research article synthesis of fluorinated amphiphilic block ...synthesis of uorinated amphiphilic...

Research ArticleSynthesis of Fluorinated Amphiphilic Block CopolymersBased on PEGMA HEMA and MMA via ATRP and CuAACClick Chemistry

Fatime Eren Erol1 Deniz Sinirlioglu2 Sedat Cosgun3 and Ali Ekrem Muftuoglu4

1 Department of Chemistry Faculty of Arts and Science Yildiz Technical University Davutpasa CampusEsenler 34220 Istanbul Turkey

2Department of Chemistry Faculty of Arts and Science Fatih University Buyukcekmece 34500 Istanbul Turkey3 Department of Chemistry Medical Laboratory Techniques Vocational School of Medical Sciences Fatih UniversityMaltepe 34840 Istanbul Turkey

4Department of Chemical Engineering Faculty of Chemical and Metallurgical Engineering Yildiz Technical UniversityDavutpasa Campus Esenler 34220 Istanbul Turkey

Correspondence should be addressed to Ali Ekrem Muftuoglu ekremmyildizedutr

Received 6 May 2014 Accepted 27 July 2014 Published 19 August 2014

Academic Editor Ali Akbar Entezami

Copyright copy 2014 Fatime Eren Erol et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Synthesis of fluorinated amphiphilic block copolymers via atom transfer radical polymerization (ATRP) and Cu(I) catalyzedHuisgen 13-dipolar cycloaddition (CuAAC) was demonstrated First a PEGMA and MMA based block copolymer carryingmultiple side-chain acetylene moieties on the hydrophobic segment for postfunctionalization was carried out This involves thesynthesis of a series of P(HEMA-co-MMA) random copolymers to be employed as macroinitiators in the controlled synthesis ofP(HEMA-co-MMA)-block-PPEGMAblock copolymers by usingATRP followed by amodification step on the hydroxyl side groupsof HEMA via Steglich esterification to afford propargyl side-functional polymer alkyne-P(HEMA-co-MMA)-block-PPEGMAFinally click coupling between side-chain acetylene functionalities and 23456-pentafluorobenzyl azide yielded fluorinatedamphiphilic block copolymers The obtained polymers were structurally characterized by 1H-NMR 19F-NMR FT-IR and GPCTheir thermal characterizations were performed using DSC and TGA

1 Introduction

The perfluoroalkyl moieties in amphiphilic molecules pro-vide distinct properties such as hydrophobicity and lipopho-bicity high thermal and chemical stability excellent mechan-ical properties at extreme temperatures low refractive indexand a strong tendency to self-assemble [1ndash6] A great dealof attention has been paid to the incorporation of fluori-nated groups into synthetic materials which combine theadvantages of both fluorinated groups and other polymers [7ndash10] Controlled radical polymerization (CRP) can serve as apowerful synthetic tool in the production of well-defined flu-orinated polymers with various architectures having prede-termined chain lengths and low polydispersities Fluorinated

block copolymers have been synthesized previously via CRPsinvolving nitroxide mediated radical polymerization (NMP)[11 12] reversible addition fragmentation chain transferpolymerization (RAFT) [13 14] and atom transfer radicalpolymerization (ATRP) [15ndash19]

Amphiphilic block copolymers consisting of hydropho-bic fluorinated blocks and hydrophilic poly[poly(ethyleneglycol)methyl ether methacrylate] (P(PEGMA)) have beensynthesized [20ndash23] P(PEGMA) block prepared by CRPs isa versatile polymer in fine-tuning hydrophobichydrophilicbalance of the amphiphile since lengths of both P(PEGMA)and PEG side-chains can be altered Besides P(PEGMA)segments may introduce favorable characteristics to thecopolymers including water solubility low toxicity and high

Hindawi Publishing CorporationInternational Journal of Polymer ScienceVolume 2014 Article ID 464806 11 pageshttpdxdoiorg1011552014464806

2 International Journal of Polymer Science

biocompatibility [24ndash26] 23456-Pentafluorobenzyl con-taining segments have been employed as the hydrophobicpart in several studies and have accounted for the above-mentioned properties stemming from perfluoroalkyl moi-eties [27ndash29] The overall macromolecules have potential inapplications involving nonlinear optics rheology modifiersand antifouling coatings

Quite recently click reactions have attracted considerableattention in synthetic polymer chemistry owing to theirhigh specificity high tolerance of functional groups andquantitative reaction yields Cu(I) catalyzed Huisgen 13-dipolar cycloaddition (CuAAC) which occurs between anazide and an alkyne to give 123-triazole ring [30 31] hasemerged as a powerful tool in the preparation of versatilemacromolecular structures when used in conjunction withcontrolledliving radical polymerization techniques [9 32]

Herein we report the synthesis of a fluorinated amphi-philic block copolymer on the basis of combined ATRP andCu(I) catalyzed Huisgen 13-dipolar cycloaddition (CuAAC)methods To the best of our knowledge this is the first studyto report the preparation of perfluoroalkylated amphiphilicblock copolymer brushes by this approach Furthermore themethod allows for facile adaptation of a variety of other clickmoieties and fine-tunes their concentration without alteringthe size of hydrophobic segment

2 Experimental

21 Materials Methyl methacrylate (MMA 99 Aldrich)and 2-hydroxyethyl methacrylate (HEMA 99 Aldrich)were distilled before use Poly(ethylene glycol) methyl etheracrylate (PEGMA 119872

119899= 480 gmol Aldrich) was passed

through basic alumina column to remove the inhibitor Ethyl120572-bromoisobutyrate (EBIB 98 Aldrich) 23456-pen-tafluorobenzyl chloride (Aldrich 99) CuCl (ge9999Aldrich) CuBr (98 Aldrich) sodium azide (NaN

3 Sigma-

Aldrich) 22-bipyridine (bpy 99 Fluka)1198731198731198731015840 11987310158401015840 11987310158401015840-pentamethyldiethylenetriamine (PMDETA 99 Aldrich)methanol (ge999 Aldrich) 1198731198731015840-dicyclohexylcarbodiimide(DCC 99 Aldrich) 4-(dimethylamino) pyridine (DMAPge9999 Aldrich) propiolic acid (99 Aldrich) and119873119873-dimethylformamide (DMF 99 Aldrich) were used asreceived

22 Typical Procedure for the Random Copolymerizationof HEMA with MMA via ATRP (1andashd) Molar ratio ofMMA and HEMA was varied to get random copolymerswith different HEMA contents For instance to obtainP(HEMA(20)-co-MMA(80)) in which the numbers inparenthesis refer to vv percentages reagents at the molarratio of [HEMA][MMA][EBIB][CuCl][bpy] 18821125were added HEMA (172 g 160mL 13mmol) MMA (601 g640mL 60mmol) CuCl (0072 g 072mmol) ethyl 120572-bromoisobutyrate (EBIB 0142 g 072mmol) and bipyridine(bpy 0145 g 0093mmol) were mixed in a Schlenk tubeequipped with a magnetic stirring bar to which 53mLof methanol ([monomer]solvent = 15 1 vv) was addedThe tube was degassed by three freeze-pump-thaw cycles

The polymerizationflaskwas placed on amagnetic stirrer andkept there for a given period at room temperature after whichthe reaction was terminated by dipping the tube into liquidnitrogen The mixture was diluted with THF and passedthrough a silica gel column to remove the complex saltsThe solution was then concentrated and precipitated into 10-fold excess hexane The precipitate was collected by filtrationand dried in a vacuum oven at 30∘C overnight (68 conv1H-NMR (CDCl

3 ppm) 120575 = 088ndash136 (s 120572-CH

3 MMA

and HEMA) 15ndash21 (s ndashCH2 MMA and HEMA) 355 (s

ndashOCH3 MMA) 378 (t ndashCH

2OH HEMA) 405 (t ndashOCH

2

HEMA) FT-IR (cmminus1) 3540 (ndashOH stretching) 2957 (ndashCHaliphatic stretching) 1726 (ndashC=O stretching) and 1151 (ndashCndashOndashCndash stretching)

23 Block Copolymerization of PEGMA Using Poly(HEMA-co-MMA)Macroinitiator via ATRP (2b 2d) In a typical pro-cedure P(HEMA(20)-co-MMA(80)) (1b) macroinitiator(041 g 0045mmol) PEGMA (872 g 18mmol) monomerCuBr (0007 g 0045mmol) and PMDETA (0016 g009mmol) were dissolved in methanolwater mixture(MeOHwater = 2 1 vv) in a Schlenk tube equipped witha magnetic stirring bar The reaction mixture was degassedby three freeze-pump-thaw cycles backfilled with nitrogenand kept in a magnetic stirrer at room temperature Afterthe given period the Schlenk tube was immersed into liquidnitrogen to terminate the reaction Upon reaching roomtemperature the mixture was diluted with THF and passedthrough a silica gel column to remove the copper salt Thesolutionwas completely dried in a rotary evaporator and thensubjected to dialysis against regularly replaced distilled waterto remove PEGMA monomer (spectraPor membranes cut-off 1000Da) The solution was again evaporated to drynessin a rotary evaporator The residue was dissolved in THFand precipitated into 10-fold excess hexane The precipitatewas collected by filtration and dried in vacuo overnightYield 75 1H-NMR (CDCl

3 ppm) 120575 = 084ndash14 (s 120572-CH

3

MMA and HEMA) 18ndash21 (s ndashCH2 MMA and HEMA)

23ndash25 (d ndashCH2 PEGMA) 338 (s CH

3Ondash PEGMA) 355

(s CH3Ondash MMA) 365 (t ndashCH

2Ondash PEGMA) 384 (t

ndashOCH2ndash HEMA) 41-42 (t ndashCH

2OH and ndashCH

2CH2O

HEMA and PEGMA) FT-IR (cmminus1) 3550 (ndashOH stretching)2870 (ndashCH aliphatic stretching) 1733 (ndashC=O stretching)and 1095 (ndashCndashOndashCndash stretching)

24 Synthesis of Alkyne-P(HEMA-co-MMA)-block-PPEGMA(3b 3d) The reagents were used according to the followingmolar ratios [side-chain OH][DCC][DMAP][propiolicacid] 11601615 To obtain alkyne-P(HEMA-co-MMA)-block-PPEGMA (3b 3d) P(HEMA-co-MMA)-block-PPEGMA (2b 2d) (05 g 0008mmol) DCC (0053 g0256mmol) DMAP (0003 g 00256mmol) and propiolicacid (0017 g 024mmol) were added in a round-bottomflask and dissolved in 50mL CH

2Cl2under stirring at room

temperature Then the mixture was concentrated in therotary evaporator and precipitated in 10-fold excess hexaneYield 87 1H-NMR (CDCl

3 ppm) 120575 = 084ndash14 (s 120572-CH

3


International Journal of Polymer Science 3

+

+

Click

O

OO

O

O

OO

OO

OO

O

O

O

OOO

OO

xx

yy

zBr

CH3

O

O

Oz

n

Br

CH3

FF

FF

F

FF

F

F

F

N3

n

Figure 1 Schematic illustration of click coupling between PEGMA based amphiphilic block copolymers bearing pendant clickable sites andazide-functional group

23-24 (d ndashCH2 PEGMA) 257 (s ndashOCequivCH) 338 (s

CH3Ondash PEGMA) 355 (s CH

3Ondash MMA) 363 (t ndashCH

2O

PEGMA) 382 (t ndashOCH2 HEMA) 41-42 (t ndashCH

2OH

and ndashCH2CH2O HEMA and PEGMA) FT-IR (cmminus1) 3320

(ndashCequivCH stretching) 2875 (ndashCH aliphatic stretching) 2350(ndashCequivCH stretching) 1735 (ndashC=O stretching) and 1099(ndashCndashOndashCndash eter stretching)

25 Synthesis of 23456-Pentafluorobenzyl Azide NaN3

(065 g 001mol) and 23456-pentafluorobenzyl chloride(2 g 0008mol) were dissolved in 50mL 119873119873-dimethyl-formamide in a round-bottomed flask equipped with amagnetic stirrer The reaction solution was stirred for 24 h atroom temperature [33ndash36] Then DMF was removed underreduced pressure in a rotary evaporator and the remainingsolid was dissolved in CH

2Cl2 The mixture was washed

thoroughly with water The organic layer was removed andrecovered solid was dried under vacuum at 25∘C Yield 801H-NMR (CDCl

3 ppm) 120575 = 367 (s ndashCH

2) FT-IR (cmminus1)

2110 (ndashN3stretching) 1650ndash1500 (ndashC=Cndash stretching) and

1235 (ndashCF stretching) 19F-NMR (CDCl3 ppm) 120575 = o ndash142

(2F) p ndash151 (1F)m ndash161 (2F)

26 Click Coupling Reaction of Alkyne-P(HEMA-co-MMA)-block-PPEGMA with 23456-Pentafluorobenzyl Azide (4)The reagents were used according to the following molarratios [side-chain acetylene][ndashN

3][CuBr][PMDETA] 11

2525 Alkyne-P(HEMA-co-MMA)-block-PPEGMA (03 g0005mmol) (3b) was dissolved together with 23456-pentafluorobenzyl azide (0016 g 007mmol) in degassedDMF under nitrogen To the reaction mixture CuBr (0025 g0176mmol) and PMDETA (0031 g 0176mmol) were addedwhile the solution was being purged with nitrogen Then

it was stirred for 48 h at room temperature after whichthe mixture was diluted with THF and passed through asilica gel column to remove the copper salt [34ndash36] Finallyexcess solvent was removed in a rotary-evaporator and theresultant solution was poured into 10-fold excess hexane forprecipitationThe solidwas collected by filtration and dried invacuo overnight (For 23456-pentafluorobenzyl functionalP(HEMA-co-MMA)-block-PPEGMA yield 83 1H-NMR(CDCl

3 ppm) 120575 = 084ndash158 (s 120572-CH

3 MMA and HEMA)

183 (s ndashCH2 MMA and HEMA) 230 (d ndashCH

2 PEGMA)

338 (s CH3Ondash PEGMA) 356 (s CH

3Ondash MMA) 365 (t

ndashCH2O PEGMA) 390 (t ndashOCH

2 HEMA) 40ndash417 (t ndash

CH2CH2and ndashCH

2CH2O HEMA and PEGMA) 447 (s ndash

CH2ndashN3) 764 (s ndashCH from triazole ring) FT-IR (cmminus1)

2870 (ndashCH aliphatic stretching) 1733 (ndashC=O stretching) and1095 (ndashCndashOndashCndash stretching))

27 Characterizations FT-IR spectra were recorded using aBruker Alpha-P in ATR in the range of 4000ndash400 cmminus1 1H-NMR spectra were recorded using a 400MHz Bruker Avancespectrometer in CDCl

3 Chemical shifts are reported in ppm

relative to TMS as internal standardThermal stabilities of the membranes were analyzed by

a PerkinElmer STA 6000 Thermal Analyzer The samples (sim10mg) were heated between 30ndash750∘C under N

2atmosphere

at a scanning rate of 10∘Cmin PerkinElmer JADE Differ-ential Scanning Calorimetry (DSC) was used to investigatethe thermal transitions of the samples The samples (sim10mg)were put into aluminum pans and then heated to the desiredtemperature at a rate of 10∘Cmin under nitrogen atmosphere

Gel-permeation chromatography (GPC) measurementswere performed on THF solutions of the polymers usingan Agilent GPC 1100 instrument The measurements werestandardized against THF solutions of polystyrene standards


O

O

O

O

O O

O

O O

O

OO O

Br

Br

Br

Br

O

OO O O

O O O

O

O

O

O

O

OO

O

NN

N

O

O OO O

O

O

O

O O OO O

O

O

HO

HO

OH

OH

+

+

+

+

EBIBCuClbpyCH3OH

x y

x y z

x y z

x y z

P(HEMA-co-MMA)

CH3n

CH3

CH3

CH3

n

n

n

CuBrPMDETAMeOHH2O

P(HEMA-co-MMA)-block-PPEGMA

Alkyne-P(HEMA-co-MMA)-block-PPEGMA

16 eq DCC016 eq DMAP

CH2Cl2

CuBrPMDETA

rt

FF

FF

F

N3

FF

F

FF

(1)

(1)

(2)

(2)

(3)

(3)

(4)

Figure 2 Synthesis of alkyne-P(HEMA-co-MMA)-block-PPEGMA (3) and its click coupling reaction (4)

3 Results and Discussion

A novel approach combining ATRP with Cu(I) catalyzedHuisgen 13-dipolar cycloaddition (CuAAC) in the prepara-tion of a fluorinated amphiphilic block copolymer has beendemonstrated (Figure 1) Synthesis of polymers based onMMA and PEGMA carrying clickable moieties for further

functionalization was carried out in a three-step strategyas depicted in Figure 2 First a series of precursor randomcopolymers (1andash1d) P(HEMA-co-MMA) were prepared viaATRP of MMA and HEMA In the second step the obtainedpolymer was employed as a macroinitiator in ATRP ofPEGMA to afford the block copolymer (2b 2d) P(HEMA-co-MMA)-block-PPEGMA


Table 1 Conditionsa and results for the synthesis of P(HEMA-co-MMA)

Entry Comonomers in feed ( volume) Polymer Time (h) bConv () c119872119899GPC

d119872119899theo

ePDI1 HEMA(5)-MMA(95) (1a) 17 91 9300 9420 1392 HEMA(20)-MMA(80) (1b) 12 68 5850 7360 1293 HEMA(30)-MMA(70) (1c) 10 60 5500 6690 1294 HEMA(50)-MMA(50) (1d) 7 43 4384 5100 123a[Monomer]solvent = 15 1 vv [M][I][CuCl][bpy] 1001125 ethyl 120572-bromoisobutyrate was used as an initiator and temperature rt bdeterminedgravimetrically cdetermined from GPC measurements dcalculated by using formula 119872119899theo = 119872119908monomer times [Monomer][Initiator] times Conv +119872119908initiator

edetermined from GPC measurements

Finally propargyl moieties were introduced via theSteglich esterification between the hydroxyl side-function-alities of HEMA and propiolic acid Alkyne-P(HEMA-co-MMA)-block-PPEGMA (3b 3d) was then click-coupledwith model compound namely 23456-pentafluorobenzylazide to yield (4) Copolymerization of methyl methacry-late (MMA) and 2-hydroxyethyl methacrylate (HEMA)was carried out via ATRP using ethyl 120572-bromoisobutyrate(EBIB) CuCl and bipyridine as initiator catalyst and lig-and respectively at room temperature in methanol Con-ditions and results are summarized in Table 1 Molar ratioof MMA and HEMA was varied to get random copol-ymers with different HEMA contents For instance toobtain P(HEMA(20)-co-MMA(80)) in which the numbersin parenthesis refer to vv percentages reagents at the molarratio of [HEMA][MMA][EBIB][CuCl][bpy] 18821125were added

Chemical structures of the copolymers were identifiedusing several techniques The FT-IR spectra of four differentcompositions of copolymers P(HEMA-co-MMA) are givenin Figure 3 The broad band at 3540 cmminus1 due to the ndashOHstretching increasing with the HEMA content in the copoly-mers was an apparent characteristic peak of the series The ndashCH stretching appeared around 2957 cmminus1The characteristicndashC=O stretching band in both HEMA andMMA units in thecopolymer occurred at 1726 cmminus1 [37 38]The strong ndashCndashOndashCndash type ester stretching band appeared at 1151 cmminus1 [38]

The 1H-NMR spectra of P(HEMA-co-MMA) copolymersare given in Figure 4The signal formethyl protons of ndashOCH

3

(a) in MMA units appeared at 355 ppm [38 39] The signalsof 120572-CH

3protons were seen at 088ndash136 ppm in both MMA

and HEMA units while for methylene protons they werein the range of 15ndash21 ppm The signals at 378 ppm (b) and405 ppm (c) correspond to ndashCH

2OH and ndashCH

2O protons

respectively [38]Copolymer compositions from 1H-NMR were calculated

by integral area of the ndashOCH3and ndashOCH

2protons using the

following [38]

Molar percent of HEMA = (11198872)

[(11198872) + (11198863)]times 100 (1)

The copolymer compositions obtained from 1H-NMRagreed well with the chargedmonomer ratio in feed as shownin Table 2

Tran

smitt

ance

(au

)

P(HEMA(5)-co-MMA(95))P(HEMA(20)-co-MMA(80))P(HEMA(30)-co-MMA(70))P(HEMA(50)-co-MMA(50))

4000 3000 2000 1000

Wavenumber (cmminus1)

Figure 3 FT-IR spectra of P(HEMA-co-MMA) copolymers

Polymerization of poly(ethylene glycol) methyl etheracrylate was carried out via ATRP using P(HEMA(20)-co-MMA(80)) (1b) and P(HEMA(50)-co-MMA(50)) (1d) asmacroinitiator and CuBrPMDETA as catalyst system atroom temperature inmethanolwater Conditions and resultsare summarized in Table 3

For both P(HEMA-co-MMA)-block-PPEGMA (2b 2d)block copolymers the 1H-NMR spectrum exhibited signalsoriginating from 120572ndashCH

3protons and ndashCH

2protons between

084ndash14 ppm and 18ndash21 ppm respectively in both MMAand HEMA units [38] as depicted in Figure 5 The appear-ance of signals at 23ndash25 ppm and 338 ppm was attributed tondashCH2and CH

3Ondash protons arising from PEGMA units [39ndash

41] The methyl protons for ndashOCH3in MMA units were at

355 ppm while ndashCH2O protons in PEGMA units appeared

at 365 ppm [24 32 34] Methylene protons of ndashCH2OH in

HEMA and ndashCH2in PEGMA gave a sharp signal around

42 ppm [38ndash41]Figure 6 shows the DSC curves of P(HEMA-co-MMA)

copolymers (1b and 1d) recorded between 0ndash180∘C A sub-stantial decrease in the glass transition temperature withincreasing HEMA content was observed which agreed withthe literature [38] The 119879

119892of P(HEMA(20)-co-MMA(80))

(1b) and P(HEMA(50)-co-MMA(50)) (1d) were detected


P(HEMA(5)-co-MMA(95))

CH2

CH3 CH3

C Cc cx y

O OO

OH

OaCH3

H2H2

H2C

a

bb

c

c

40 30 20 10

(a)


a

bc

40 30 20 10

(b)


a

bc

40 30 20 10

(c)


abc

40 30 20 10

ppm (t1)

(d)

Figure 4 1H-NMR spectra of P(HEMA-co-MMA) copolymers (1andash1d)

Table 2 Compositions of P(HEMA-co-MMA) obtained from 1H-NMR data

Comonomers in feed (volumeratio)a

Comonomers in feed HEMAMMA(mol )b

Comonomers in polymer HEMAMMA (mol )c

HEMA(5)-MMA(95) 44956 47953HEMA(20)-MMA(80) 181819 185815HEMA(30)-MMA(70) 274726 250750HEMA(50)-MMA(50) 469531 491509aby volume bby moles and ccalculated from 1H-NMR

Table 3 Conditionsa and results for the synthesis of P(HEMA-co-MMA)-block-PPEGMA

Entry Macroinitiator P(HEMA-119888119900-MMA)-119887119897119900119888119896-PPEGMA b119872119899GPC

c119872119899theo

d119872119908119872119899

1 (1b) (2b) 112620 108080 1582 (1d) (2d) 58040 60440 139a[MeOH]water = 2 1 vv [M][I][CuBr][PMDETA] 400112 temperature rt bdetermined from GPC measurements ccalculated by using formula119872119899theo =119872119908monomer times [Monomer][Initiator]times Conv +119872119908initiator

d119872119899 the number average molecular weight119872119908 the weight average molecular weight

around 100∘C and 57∘C [38] respectively PHEMA andPMMA homopolymers as well as their copolymers areamorphous and do not show any melting temperature asexpected Figure 7 shows DSC analysis of P(HEMA-co-MMA)-block-PPEGMA (2b and 2d) evaluated during theheating process from ndash48 to 180∘C P(HEMA-co-MMA)-block-PPEGMA shows a119879

119898due to the presence of crystalline

domains originating from PPEGMA blocks The presence of119879119898at around 0∘C supports the block copolymer formation

It is also noteworthy that 119879119898values for (2b) and (2d) are

almost the same although different feed ratios of precursor

P(HEMA-co-MMA) were employed in the block copolymerformation whichmight have resulted in an evident shifting of119879119898since variation of HEMA and MMA content can possibly

affect the crystallinity in the microstructure However acareful inspection reveals that the final copolymer content(in mol) of 2b (HEMAMMAPEGMA sim 1422) and 2d(HEMAMMAPEGMA sim 4422) is very close and the factthat 119879

119898values are nearly the same is just as expected

The thermal stabilities of P(HEMA-co-MMA) copoly-mers (1b and 1d) and P(HEMA-co-MMA)-block-PPEGMA(2b and 2d) block copolymers were analyzed as well as


Table 4 Temperatures of various decompositions and char yield in N2at 750∘C

Sample Temperature of 5weight loss (∘C)

Temperature of10 weight loss

(∘C)

Temperature of therapid weight loss119879max (

∘C)

Char yield at 750(∘C) in119873

2(wt)

P(HEMA(20)-119888119900-MMA(80)) 213 292 367 0P(HEMA(50)-119888119900-MMA(50)) 184 251 371 0P(HEMA(20)-119888119900-MMA(80))-119887119897119900119888119896-PPEGMA 185 277 327 0P(HEMA(50)-119888119900-MMA(50))-119887119897119900119888119896-PPEGMA 298 334 350 0

70 60 50 40 30 20 10

O

HO

O

O O OOO O

O

Bra b c

c

d e

f g

h i

j

k

l m

n

n

CH3

x y z

b g l

f

j m

n

k

d h

a c e i

ppm (t1)

Figure 5 The 1H-NMR spectrum of P(HEMA-co-MMA)-block-PPEGMA (2b 2d)

180

182

184

186

188

190

192

194

196

198

200

202

204205

0 20 40 60 80 100 120 140 160 180

Temperature (∘C)

Tg half Cp extrapolated = 10020∘C




Hea

t flow

endo

dow

n (m

W)

Heat flow endo down (mW)Heat flow endo down (mW)

= 0248 Jglowast∘C

= 0198 Jglowast∘C

ΔCp

ΔCp

Figure 6The DSC curves of P(HEMA(20)-co-MMA(80)) (1b) andP(HEMA(50)-co-MMA(50)) (1d) copolymers

shown in Figure 8 The TGA curves of P(HEMA-co-MMA)copolymers with varying composition of HEMA indicated athermal stability up to 340ndash350∘C [38] On the other handin the analysis of P(HEMA-co-MMA)-block-PPEGMA blockcopolymers the decomposition temperatures are shifted torelatively lower values with the incorporation of PEGMAunits

The temperature of 5 weight loss the temperature of10 weight loss the temperature of the rapid weight loss(119879max) before 750

∘C and the char yield at 750∘C in nitrogenare summarized in Table 4

16

18

20

22

24

26

28

30

32

minus40 minus20 0 20 40 60 80 100 120 140 160 180

Temperature (∘C)

Hea

t flow

endo

dow

n (m

W)

P(HEMA(20)-co-MMA(80))-block-PPEGMA



Figure 7 The DSC of P(HEMA-co-MMA)-block-PPEGMA (2b2d)

100

80

60

40

20

0

0 200 400 600 800

Wei

ght (

)

Temperature (∘C)

P(HEMA(20)-co-MMA(80))-block-PPEGMAP(HEMA(50)-co-MMA(50))-block-PPEGMA

P(HEMA(20)-co-MMA(80))P(HEMA(50)-co-MMA(50))

Figure 8 TGA curves of P(HEMA-co-MMA) (1b 1d) andP(HEMA-co-MMA)-block-PPEGMA (2b 2d)

Propargyl side-functional block copolymers alkyne-P(HEMA-co-MMA)-block-PPEGMA (3b and 3d) were pre-pared by the Steglich esterification between hydroxyl groupsof HEMA and propiolic acid in the presence of DCC and


C HTr

ansm

ittan

ce (a

u)

4000 3000 2000 1000


P(P(HEMA(20)-co-MMA(80))-block-PPEGMA)Propargyl-terminated polymer

(a)

Tran

smitt

ance

(au

)

4000 3000 2000 1000


C H


(b)

Figure 9 The FT-IR spectra of P(HEMA-co-MMA)-block-PPEGMA (2b 2d) and alkyne-P(HEMA-co-MMA)-block-PPEGMA (3b 3d)

DMAP at room temperature [35]TheGPC analysis providedevidence for the success of reaction As expected there was aslight increase in the119872

119899values

For P(HEMA(20)-MMA(80))-b-PPEGMA (2b) 119872119899

changed from 112620 to 113350 (PDI = 153) while forP(HEMA(50)-MMA(50))-b-PPEGMA) (2d) there was achange from 58040 to 59514 (PDI = 139) which showed theincorporation of propargyl units

Further proof was supplied by FT IR analysis as depictedin Figure 9 As compared to the spectrum of P(HEMA-co-MMA)-block-PPEGMA two new bands (2b 2d) appearedat around 2350 and 3320 cmminus1 in the spectrum of alkyne-P(HEMA-co-MMA)-block-PPEGMA (3b 3d) which wereassigned to the stretching vibration of the alkyne group [35]

Finally to assess the applicability of alkyne-P(HEMA-co-MMA)-block-PPEGMA in postfunctionalization 3b and3d having different molecular weights were click coupledwith 23456-pentafluorobenzyl azide For this purposefirst 23456-pentafluorobenzyl azide was prepared uponreaction between their halo-compounds and NaN

3in DMF

at room temperature The halogen atoms were substitutedwith azide groups via nucleophilic substitution The FT-IRspectra are illustrated in Figure 10 The appearance of sharpndashN3stretching bands between 2110 cmminus1 and 2090 cmminus1 for

23456-pentafluorobenzyl azide supported that azidationwas successful [32ndash36 42 43]

In the second step Cu(I) catalyzed Huisgen 13-dipolarcycloaddition (CuAAC) was carried out between propar-gyl side functionalities on the backbone and 23456-pentafluorobenzyl azide The 1H-NMR spectra of the clickproducts are illustrated in Figure 11 The appearance of thenew signals at 764 (f) and 559 (e) ppm regarding themethine proton and the methylene protons adjacent to thetriazole ring respectively were observed [32 34ndash36 42 43]

Further evidence for the incorporation of 23456-pentafluorobenzene was provided by 19F-NMR analysis aspresented in Figure 12 The signals which appeared in thespectrum of 23456-pentafluorobenzyl azide also existedin that of click product The signals detected at ndash142 ppmndash151 ppm and ndash161 ppm originated from the aromatic fluo-rines 2F at o-position 1F at p-position and 2F atm-positionrespectively [44]

4000 3500 3000 2500 2000 1500 1000 500

3Tr

ansm

ittan

ce (a

u)


2345-Pentauorobenzyl bromideAzido-2345-pentauorobenzene

mdashN

Figure 10 The FT-IR spectra of 23456-pentafluorobenzyl chlo-ride and azido-2345-pentafluorobenzene

80 70 60 50 40 30 20 10

ppm (t1)

O

O

OO

OO O

O OO Ox y z

Br

F

FF

F

F

NN

N

f

f

e

e

CH3

CH2

n

CH

Figure 11 The 1H-NMR spectra of the click product (4)

4 Conclusions

The strategy of combining ATRP with Cu(I) catalyzed Huis-gen 13-dipolar cycloaddition (CuAAC) in the preparation ofa novel clickable amphiphilic block copolymer was demon-strated First P(HEMA-co-MMA) copolymers were preparedvia ATRP Molar ratio of MMA and HEMA was varied


Click product

0 minus50 minus100 minus150 minus200

ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)

Figure 12 (a) The 19F-NMR spectra of click product (b) the 19F-NMR spectra of 23456-pentafluorobenzyl azide

to get random copolymers with different HEMA contentsThe copolymer compositions were obtained from 1H-NMRand agreed well with the charged monomer ratio in feedPolymerization of poly(ethylene glycol) methyl ether acrylatewas carried out via ATRP using P(HEMA(20)-co-MMA(80))(1b) and P(HEMA(50)-co-MMA(50)) (1d) as macroinitiatorto get block copolymers GPC analysis of the obtained blockcopolymers was measured as 119872

119899= 112620 (PDI = 158)

and 119872119899= 58040 (PDI = 139) respectively Both 1H-NMR

and FT-IR spectra showed peaks associated with MMAHEMA and PEGMA repeating units Thermal properties ofthe copolymers and the block copolymers were also studiedby TGA and DSC For the copolymers a thermal stabilityof up to 340ndash350∘C was detected In the next step alkyne-P(HEMA-co-MMA)-block-PPEGMA (3b 3d) was preparedby the Steglich esterification between hydroxyl groups ofHEMA and propiolic acid in the presence of DCC andDMAP at room temperature Finally Cu(I) catalyzed Huis-gen 13-dipolar cycloaddition (CuAAC) was employed as atool for postfunctionalization The click coupling betweenpropargyl side functionalities on the backbone and 23456-pentafluorobenzyl azide were evidenced by 1H-NMR and19F-NMR This synthetic route might be useful in tuningthe lengths of the hydrophilic and hydrophobic segmentsin amphiphilic polymers as well as the average number offunctionalities situated in the side chain

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This work was supported by the Scientific Research Fund ofFatih University under the Project no P50021002 2

References

[1] B Jiang L Zhang J Shi et al ldquoSynthesis characteriza-tion and bulk properties of well-defined poly(hexafluorobutylmethacrylate)-block-poly(glycidyl methacrylate) via consecu-tive ATRPrdquo Journal of Fluorine Chemistry vol 153 pp 74ndash812013

[2] M P Krafft ldquoControlling phospholipid self-assembly and filmproperties using highly fluorinated componentsmdashfluorinatedmonolayers vesicles emulsions and microbubblesrdquo Biochimievol 94 no 1 pp 11ndash25 2012

[3] E Amado and J Kressler ldquoTriphilic block copolymers withperfluorocarbon moieties in aqueous systems and their bio-chemical perspectivesrdquo SoftMatter vol 7 no 16 pp 7144ndash71492011

[4] H Nakahara M Tsuji Y Sato M P Krafft and O ShibataldquoLangmuir monolayer miscibility of single-chain partially fluo-rinated amphiphiles with tetradecanoic acidrdquo Journal of Colloidand Interface Science vol 337 no 1 pp 201ndash210 2009

[5] M Broniatowski and P Dynarowicz-Łatka ldquoSemifluorinatedalkanesmdashprimitive surfactants of fascinating propertiesrdquoAdvances in Colloid and Interface Science vol 138 no 2 pp63ndash83 2008

[6] M P Krafft ldquoFluorocarbons and fluorinated amphiphiles indrug delivery and biomedical researchrdquo Advanced Drug Deliv-ery Reviews vol 47 no 2-3 pp 209ndash228 2001

[7] K KGoli O J Rojas and J Genzer ldquoFormation and antifoulingproperties of amphiphilic coatings on polypropylene fibersrdquoBiomacromolecules vol 13 no 11 pp 3769ndash3779 2012

[8] H Peng K JThurecht I Blakey E Taran and A KWhittakerldquoEffect of solvent quality on the solution properties of assem-blies of partially fluorinated amphiphilic diblock copolymersrdquoMacromolecules vol 45 no 21 pp 8681ndash8690 2012

[9] P Scholtysek Z Li J Kressler and A Blume ldquoInteractionsof DPPC with semitelechelic poly(glycerol methacrylate)s withperfluoroalkyl end groupsrdquo Langmuir vol 28 no 44 pp 15651ndash15662 2012

[10] Z Zhao H Ni Z Han et al ldquoEffect of surface composi-tional heterogeneities and microphase segregation of fluori-nated amphiphilic copolymers on antifouling performancerdquoACS Applied Materials and Interfaces vol 5 no 16 pp 7808ndash7818 2013

[11] A Bruno ldquoControlled radical (Co)polymerization of fluo-romonomersrdquoMacromolecules vol 43 no 24 pp 10163ndash101842010

[12] N M L Hansen K Jankova and S Hvilsted ldquoFluoropolymermaterials and architectures prepared by controlled radicalpolymerizationsrdquo European Polymer Journal vol 43 no 2 pp255ndash293 2007

[13] A Chakrabarty and N K Singha ldquoTailor-made polyfluo-roacrylate and its block copolymer by RAFT polymerization inminiemulsion improved hydrophobicity in the core-shell blockcopolymerrdquo Journal of Colloid and Interface Science vol 408 pp66ndash74 2013


[14] J M Bak and H Lee ldquoNovel thermoresponsive fluorinateddouble-hydrophilic poly[N-(22- difluoroethyl)acrylamide]-b-[N-(2-fluoroethyl)acrylamide] block copolymersrdquo Journal ofPolymer Science A Polymer Chemistry vol 51 no 9 pp 1976ndash1982 2013

[15] T L Bucholz andY Loo ldquoPhase behavior of near-monodispersesemifluorinated diblock copolymers by atom transfer radicalpolymerizationrdquoMacromolecules vol 39 no 18 pp 6075ndash60802006

[16] G-D Fu Z-L Yuan E-T Kang K-G Neoh D MLai and A C H Huan ldquoNanoporous ultra-low-dielectric-constant fluoropolymer films via selective UV decompositionof poly(pentafluorostyrene)-block-poly(methyl methacrylate)copolymers prepared using atom transfer radical polymeriza-tionrdquo Advanced Functional Materials vol 15 no 2 pp 315ndash3222005

[17] W Guo X Tang J Xu et al ldquoSynthesis characterization andproperty of amphiphilic fluorinated abc-type triblock copoly-mersrdquo Journal of Polymer Science A Polymer Chemistry vol 49no 7 pp 1528ndash1534 2011

[18] E Martinelli S Agostini G Galli et al ldquoNanostructured filmsof amphiphilic fluorinated block copolymers for fouling releaseapplicationrdquo Langmuir vol 24 no 22 pp 13138ndash13147 2008

[19] G P He G W Zhang J P Hu et al ldquoLow-fluorinated hom-opolymer from heterogeneous ATRP of 222-trifluoroethylmethacrylate mediated by copper complex with nitrogen-basedligandrdquo Journal of Fluorine Chemistry vol 132 no 9 pp 562ndash572 2011

[20] N M L Hansen M Gerstenberg D M Haddleton and SHvilsted ldquoSynthesis characterization and bulk properties ofamphiphilic copolymers containing fluorinated methacrylatesfrom sequential copper-mediated radical polymerizationrdquo Jour-nal of Polymer Science A Polymer Chemistry vol 46 no 24 pp8097ndash8111 2008

[21] NM LHansenDMHaddleton and SHvilsted ldquoFluorinatedbio-acceptable polymers via anATRPmacroinitiator approachrdquoJournal of Polymer Science A Polymer Chemistry vol 45 no 24pp 5770ndash5780 2007

[22] Y Chen L Chen H Nie E T Kang and R H VoraldquoFluorinated polyimides grafted with poly(ethylene glycol) sidechains by the RAFT-mediated process and their membranesrdquoMaterials Chemistry and Physics vol 94 no 2-3 pp 195ndash2012005

[23] D Burger J Gisin and E Bartsch ldquoSynthesis of stericallystabilized perfluorinated aqueous laticesrdquo Colloids and SurfacesA Physicochemical and Engineering Aspects vol 442 pp 123ndash131 2014

[24] Y Liu J Y Lee E T Kang P Wang and K L Tan ldquoSynthesischaracterization and electrochemical transport properties ofthe poly(ethyleneglycol)-grafted poly(vinylidenefluoride) na-noporous membranesrdquo Reactive and Functional Polymers vol47 no 3 pp 201ndash213 2001

[25] P Wang K L Tan and E T Kang ldquoSurface modificationof poly(tetrafluoroethylene) films via grafting of poly(ethyleneglycol) for reduction in protein adsorptionrdquo Journal of Bioma-terials Science Polymer Edition vol 11 no 2 pp 169ndash186 2000

[26] Y Nakayama M Miyamura Y Hirano K Goto and T Mat-suda ldquoPreparation of poly(ethylene glycol)-polystyrene blockcopolymers using photochemistry of dithiocarbamate as areduced cell-adhesive coating materialrdquo Biomaterials vol 20no 10 pp 963ndash970 1999

[27] G D Fu Z H Shang L Hong E T Kang and K G NeohldquoNanoporous ultralow-dielectric-constant fluoropolymer filmsfrom agglomerated and crosslinked hollow nanospheres of poly(pentafluorostyrene)-block-poly(divinylbenzene)rdquo AdvancedMaterials vol 17 no 21 pp 2622ndash2626 2005

[28] M Paz-Pazos and C Pugh ldquoSynthesis of optically activecopolymers of 2345 6-pentafluorostyrene and 120573-pinene withlow surface energiesrdquo Journal of Polymer Science A PolymerChemistry vol 44 no 9 pp 3114ndash3124 2006

[29] A M Granville S G Boyes B Akgun M D Foster andW J Brittain ldquoThermoresponsive behavior of semifluorinatedpolymer brushesrdquoMacromolecules vol 38 no 8 pp 3263ndash32702005

[30] H C Kolb M G Finn and K B Sharpless ldquoClick chemistrydiverse chemical function from a few good reactionsrdquo Ange-wandte ChemiemdashInternational Edition vol 40 no 11 pp 2004ndash2021 2001

[31] V V Rostovtsev G Green V V Fokin and K B SharplessldquoA stepwise huisgen cycloaddition process copper(I)-catalyzedregioselective ligation of azides and terminal alkynesrdquo Ange-wandte Chemie International Edition vol 41 no 14 pp 2596ndash2599 2002

[32] M Ergin B Kiskan B Gacal and Y Yagci ldquoThermally curablepolystyrene via click chemistryrdquoMacromolecules vol 40 no 13pp 4724ndash4727 2007

[33] G D Fu E T Kang and K G Neoh ldquoThree-dimensionallyordered porous membranes prepared via self-assembly andreverse micelle formation from well-defined amphiphilic blockcopolymersrdquo Langmuir vol 21 no 8 pp 3619ndash3624 2005

[34] M Degirmenci and N Genli ldquoSynthesis of well-definedtelechelic macrophotoinitiator of polystyrene by combinationof ATRP and click chemistryrdquo Macromolecular Chemistry andPhysics vol 210 no 19 pp 1617ndash1623 2009

[35] D Sinirlioglu and A E Muftuoglu ldquoSynthesis of an inorganic-organic hybrid material based on polyhedral oligomericsilsesquioxane and polystyrene via nitroxide-mediated poly-merization and click reactionsrdquo Designed Monomers and Poly-mers vol 14 no 3 pp 273ndash286 2011

[36] O Eren M Gorur B Keskin and F Yilmaz ldquoSynthe-sis and characterization of ferrocene end-capped poly(120576-caprolactone)s by a combination of ring-opening polymeriza-tion and ldquoclickrdquo chemistry techniquesrdquo Reactive and FunctionalPolymers vol 73 no 1 pp 244ndash253 2013

[37] S Arifuzzaman A E Ozcam K Efimenko D A Fischer andJ Genzer ldquoFormation of surface-grafted polymeric amphiphiliccoatings comprising ethylene glycol and fluorinated groups andtheir response to protein adsorptionrdquo Biointerphases vol 4 no2 pp FA33ndashFA44 2009

[38] E Vargun M Sankir B Aran N D Sankir and A UsanmazldquoSynthesis and characterization of 2-hydroxyethyl methacrylate(HEMA) andmethyl methacrylate (MMA) lrdquo Journal of Macro-molecular Science A Pure and Applied Chemistry vol 47 no 3pp 235ndash240 2010

[39] M M Ali and H D H Stover ldquoWell-defined amphiphilicthermosensitive copolymers based on poly(ethylene glycolmonomethacrylate) andmethylmethacrylate prepared by atomtransfer radical polymerizationrdquoMacromolecules vol 37 no 14pp 5219ndash5227 2004

[40] B H Tan H Hussain Y Liu C B He and T P DavisldquoSynthesis and self-assembly of brush-type poly[poly(ethylene


glycol)methyl ether methacrylate]-block-poly(pentafluorosty-rene) amphiphilic diblock copolymers in aqueous solutionrdquoLangmuir vol 26 no 4 pp 2361ndash2368 2010

[41] B Kim H Lee S Jeong J Lee and H Paik ldquoAmphiphilicgradient copolymer of [poly(ethylene glycol) methyl ether]methacrylate and styrene via atom transfer radical polymeriza-tionrdquo Macromolecular Research vol 19 no 12 pp 1257ndash12632011

[42] M Degirmenci and N Genli ldquoSynthesis of poly(cyclohexeneoxide)-block-polystyrene by combination of radical-promotedcationic polymerization atom transfer radical polymerizationand click chemistryrdquo Polymer International vol 59 no 6 pp859ndash866 2010

[43] O Karagollu M Gorur F Gode B Sennik and F YilmazldquoPhosphate ion sensors based on triazole connected ferrocenemoietiesrdquo Sensors and Actuators B vol 193 pp 788ndash798 2014

[44] K T Powell C Cheng K L Wooley A Singh and M WUrban ldquoComplex amphiphilic networks derived from diamine-terminated poly(ethylene glycol) and benzylic chloride-func-tionalized hyperbranched fluoropolymersrdquo Journal of PolymerScience A Polymer Chemistry vol 44 no 16 pp 4782ndash47942006

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


biocompatibility [24ndash26] 23456-Pentafluorobenzyl con-taining segments have been employed as the hydrophobicpart in several studies and have accounted for the above-mentioned properties stemming from perfluoroalkyl moi-eties [27ndash29] The overall macromolecules have potential inapplications involving nonlinear optics rheology modifiersand antifouling coatings

Quite recently click reactions have attracted considerableattention in synthetic polymer chemistry owing to theirhigh specificity high tolerance of functional groups andquantitative reaction yields Cu(I) catalyzed Huisgen 13-dipolar cycloaddition (CuAAC) which occurs between anazide and an alkyne to give 123-triazole ring [30 31] hasemerged as a powerful tool in the preparation of versatilemacromolecular structures when used in conjunction withcontrolledliving radical polymerization techniques [9 32]

Herein we report the synthesis of a fluorinated amphi-philic block copolymer on the basis of combined ATRP andCu(I) catalyzed Huisgen 13-dipolar cycloaddition (CuAAC)methods To the best of our knowledge this is the first studyto report the preparation of perfluoroalkylated amphiphilicblock copolymer brushes by this approach Furthermore themethod allows for facile adaptation of a variety of other clickmoieties and fine-tunes their concentration without alteringthe size of hydrophobic segment

2 Experimental

21 Materials Methyl methacrylate (MMA 99 Aldrich)and 2-hydroxyethyl methacrylate (HEMA 99 Aldrich)were distilled before use Poly(ethylene glycol) methyl etheracrylate (PEGMA 119872

119899= 480 gmol Aldrich) was passed

through basic alumina column to remove the inhibitor Ethyl120572-bromoisobutyrate (EBIB 98 Aldrich) 23456-pen-tafluorobenzyl chloride (Aldrich 99) CuCl (ge9999Aldrich) CuBr (98 Aldrich) sodium azide (NaN

3 Sigma-

Aldrich) 22-bipyridine (bpy 99 Fluka)1198731198731198731015840 11987310158401015840 11987310158401015840-pentamethyldiethylenetriamine (PMDETA 99 Aldrich)methanol (ge999 Aldrich) 1198731198731015840-dicyclohexylcarbodiimide(DCC 99 Aldrich) 4-(dimethylamino) pyridine (DMAPge9999 Aldrich) propiolic acid (99 Aldrich) and119873119873-dimethylformamide (DMF 99 Aldrich) were used asreceived

22 Typical Procedure for the Random Copolymerizationof HEMA with MMA via ATRP (1andashd) Molar ratio ofMMA and HEMA was varied to get random copolymerswith different HEMA contents For instance to obtainP(HEMA(20)-co-MMA(80)) in which the numbers inparenthesis refer to vv percentages reagents at the molarratio of [HEMA][MMA][EBIB][CuCl][bpy] 18821125were added HEMA (172 g 160mL 13mmol) MMA (601 g640mL 60mmol) CuCl (0072 g 072mmol) ethyl 120572-bromoisobutyrate (EBIB 0142 g 072mmol) and bipyridine(bpy 0145 g 0093mmol) were mixed in a Schlenk tubeequipped with a magnetic stirring bar to which 53mLof methanol ([monomer]solvent = 15 1 vv) was addedThe tube was degassed by three freeze-pump-thaw cycles

The polymerizationflaskwas placed on amagnetic stirrer andkept there for a given period at room temperature after whichthe reaction was terminated by dipping the tube into liquidnitrogen The mixture was diluted with THF and passedthrough a silica gel column to remove the complex saltsThe solution was then concentrated and precipitated into 10-fold excess hexane The precipitate was collected by filtrationand dried in a vacuum oven at 30∘C overnight (68 conv1H-NMR (CDCl

3 ppm) 120575 = 088ndash136 (s 120572-CH

3 MMA

and HEMA) 15ndash21 (s ndashCH2 MMA and HEMA) 355 (s

ndashOCH3 MMA) 378 (t ndashCH

2OH HEMA) 405 (t ndashOCH

2

HEMA) FT-IR (cmminus1) 3540 (ndashOH stretching) 2957 (ndashCHaliphatic stretching) 1726 (ndashC=O stretching) and 1151 (ndashCndashOndashCndash stretching)

23 Block Copolymerization of PEGMA Using Poly(HEMA-co-MMA)Macroinitiator via ATRP (2b 2d) In a typical pro-cedure P(HEMA(20)-co-MMA(80)) (1b) macroinitiator(041 g 0045mmol) PEGMA (872 g 18mmol) monomerCuBr (0007 g 0045mmol) and PMDETA (0016 g009mmol) were dissolved in methanolwater mixture(MeOHwater = 2 1 vv) in a Schlenk tube equipped witha magnetic stirring bar The reaction mixture was degassedby three freeze-pump-thaw cycles backfilled with nitrogenand kept in a magnetic stirrer at room temperature Afterthe given period the Schlenk tube was immersed into liquidnitrogen to terminate the reaction Upon reaching roomtemperature the mixture was diluted with THF and passedthrough a silica gel column to remove the copper salt Thesolutionwas completely dried in a rotary evaporator and thensubjected to dialysis against regularly replaced distilled waterto remove PEGMA monomer (spectraPor membranes cut-off 1000Da) The solution was again evaporated to drynessin a rotary evaporator The residue was dissolved in THFand precipitated into 10-fold excess hexane The precipitatewas collected by filtration and dried in vacuo overnightYield 75 1H-NMR (CDCl

3 ppm) 120575 = 084ndash14 (s 120572-CH

3


23ndash25 (d ndashCH2 PEGMA) 338 (s CH

3Ondash PEGMA) 355

(s CH3Ondash MMA) 365 (t ndashCH

2Ondash PEGMA) 384 (t

ndashOCH2ndash HEMA) 41-42 (t ndashCH

2OH and ndashCH

2CH2O

HEMA and PEGMA) FT-IR (cmminus1) 3550 (ndashOH stretching)2870 (ndashCH aliphatic stretching) 1733 (ndashC=O stretching)and 1095 (ndashCndashOndashCndash stretching)

24 Synthesis of Alkyne-P(HEMA-co-MMA)-block-PPEGMA(3b 3d) The reagents were used according to the followingmolar ratios [side-chain OH][DCC][DMAP][propiolicacid] 11601615 To obtain alkyne-P(HEMA-co-MMA)-block-PPEGMA (3b 3d) P(HEMA-co-MMA)-block-PPEGMA (2b 2d) (05 g 0008mmol) DCC (0053 g0256mmol) DMAP (0003 g 00256mmol) and propiolicacid (0017 g 024mmol) were added in a round-bottomflask and dissolved in 50mL CH

2Cl2under stirring at room

temperature Then the mixture was concentrated in therotary evaporator and precipitated in 10-fold excess hexaneYield 87 1H-NMR (CDCl

3 ppm) 120575 = 084ndash14 (s 120572-CH

3



+

+

Click

O

OO

O

O

OO

OO

OO

O

O

O

OOO

OO

xx

yy

zBr

CH3

O

O

Oz

n

Br

CH3

FF

FF

F

FF

F

F

F

N3

n





2O


2OH







3 ppm) 120575 = 367 (s ndashCH

2) FT-IR (cmminus1)





3][CuBr][PMDETA] 11



3 ppm) 120575 = 084ndash158 (s 120572-CH

3 MMA and HEMA)


2 PEGMA)


3Ondash MMA) 365 (t



CH2CH2and ndashCH








2atmosphere




O

O

O

O

O O

O

O O

O

OO O

Br

Br

Br

Br

O

OO O O

O O O

O

O

O

O

O

OO

O

NN

N

O

O OO O

O

O

O

O O OO O

O

O

HO

HO

OH

OH

+

+

+

+

EBIBCuClbpyCH3OH

x y

x y z

x y z

x y z

P(HEMA-co-MMA)

CH3n

CH3

CH3

CH3

n

n

n

CuBrPMDETAMeOHH2O




CH2Cl2

CuBrPMDETA

rt

FF

FF

F

N3

FF

F

FF

(1)

(1)

(2)

(2)

(3)

(3)

(4)








d119872119899theo






3




2OH and ndashCH

2O protons



2protons using the

following [38]


[(11198872) + (11198863)]times 100 (1)


Tran

smitt

ance

(au

)


4000 3000 2000 1000






2protons between









119892of P(HEMA(20)-co-MMA(80))




CH2

CH3 CH3

C Cc cx y

O OO

OH

OaCH3

H2H2

H2C

a

bb

c

c

40 30 20 10

(a)


a

bc

40 30 20 10

(b)


a

bc

40 30 20 10

(c)


abc

40 30 20 10

ppm (t1)

(d)









c119872119899theo

d119872119908119872119899
















(∘C)


∘C)


2(wt)


70 60 50 40 30 20 10

O

HO

O

O O OOO O

O

Bra b c

c

d e

f g

h i

j

k

l m

n

n

CH3

x y z

b g l

f

j m

n

k

d h

a c e i

ppm (t1)


180

182

184

186

188

190

192

194

196

198

200

202

204205

0 20 40 60 80 100 120 140 160 180

Temperature (∘C)





Hea

t flow

endo

dow

n (m

W)


= 0248 Jglowast∘C

= 0198 Jglowast∘C

ΔCp

ΔCp





16

18

20

22

24

26

28

30

32

minus40 minus20 0 20 40 60 80 100 120 140 160 180

Temperature (∘C)

Hea

t flow

endo

dow

n (m

W)





100

80

60

40

20

0

0 200 400 600 800

Wei

ght (

)

Temperature (∘C)






C HTr

ansm

ittan

ce (a

u)

4000 3000 2000 1000



(a)

Tran

smitt

ance

(au

)

4000 3000 2000 1000


C H


(b)



119899values





3in DMF





4000 3500 3000 2500 2000 1500 1000 500

3Tr

ansm

ittan

ce (a

u)



mdashN


80 70 60 50 40 30 20 10

ppm (t1)

O

O

OO

OO O

O OO Ox y z

Br

F

FF

F

F

NN

N

f

f

e

e

CH3

CH2

n

CH


4 Conclusions



Click product


ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)



119899= 112620 (PDI = 158)





Acknowledgment


References























































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




+

+

Click

O

OO

O

O

OO

OO

OO

O

O

O

OOO

OO

xx

yy

zBr

CH3

O

O

Oz

n

Br

CH3

FF

FF

F

FF

F

F

F

N3

n





2O


2OH







3 ppm) 120575 = 367 (s ndashCH

2) FT-IR (cmminus1)





3][CuBr][PMDETA] 11



3 ppm) 120575 = 084ndash158 (s 120572-CH

3 MMA and HEMA)


2 PEGMA)


3Ondash MMA) 365 (t



CH2CH2and ndashCH








2atmosphere




O

O

O

O

O O

O

O O

O

OO O

Br

Br

Br

Br

O

OO O O

O O O

O

O

O

O

O

OO

O

NN

N

O

O OO O

O

O

O

O O OO O

O

O

HO

HO

OH

OH

+

+

+

+

EBIBCuClbpyCH3OH

x y

x y z

x y z

x y z

P(HEMA-co-MMA)

CH3n

CH3

CH3

CH3

n

n

n

CuBrPMDETAMeOHH2O




CH2Cl2

CuBrPMDETA

rt

FF

FF

F

N3

FF

F

FF

(1)

(1)

(2)

(2)

(3)

(3)

(4)








d119872119899theo






3




2OH and ndashCH

2O protons



2protons using the

following [38]


[(11198872) + (11198863)]times 100 (1)


Tran

smitt

ance

(au

)


4000 3000 2000 1000






2protons between









119892of P(HEMA(20)-co-MMA(80))




CH2

CH3 CH3

C Cc cx y

O OO

OH

OaCH3

H2H2

H2C

a

bb

c

c

40 30 20 10

(a)


a

bc

40 30 20 10

(b)


a

bc

40 30 20 10

(c)


abc

40 30 20 10

ppm (t1)

(d)









c119872119899theo

d119872119908119872119899
















(∘C)


∘C)


2(wt)


70 60 50 40 30 20 10

O

HO

O

O O OOO O

O

Bra b c

c

d e

f g

h i

j

k

l m

n

n

CH3

x y z

b g l

f

j m

n

k

d h

a c e i

ppm (t1)


180

182

184

186

188

190

192

194

196

198

200

202

204205

0 20 40 60 80 100 120 140 160 180

Temperature (∘C)





Hea

t flow

endo

dow

n (m

W)


= 0248 Jglowast∘C

= 0198 Jglowast∘C

ΔCp

ΔCp





16

18

20

22

24

26

28

30

32

minus40 minus20 0 20 40 60 80 100 120 140 160 180

Temperature (∘C)

Hea

t flow

endo

dow

n (m

W)





100

80

60

40

20

0

0 200 400 600 800

Wei

ght (

)

Temperature (∘C)






C HTr

ansm

ittan

ce (a

u)

4000 3000 2000 1000



(a)

Tran

smitt

ance

(au

)

4000 3000 2000 1000


C H


(b)



119899values





3in DMF





4000 3500 3000 2500 2000 1500 1000 500

3Tr

ansm

ittan

ce (a

u)



mdashN


80 70 60 50 40 30 20 10

ppm (t1)

O

O

OO

OO O

O OO Ox y z

Br

F

FF

F

F

NN

N

f

f

e

e

CH3

CH2

n

CH


4 Conclusions



Click product


ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)



119899= 112620 (PDI = 158)





Acknowledgment


References























































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




O

O

O

O

O O

O

O O

O

OO O

Br

Br

Br

Br

O

OO O O

O O O

O

O

O

O

O

OO

O

NN

N

O

O OO O

O

O

O

O O OO O

O

O

HO

HO

OH

OH

+

+

+

+

EBIBCuClbpyCH3OH

x y

x y z

x y z

x y z

P(HEMA-co-MMA)

CH3n

CH3

CH3

CH3

n

n

n

CuBrPMDETAMeOHH2O




CH2Cl2

CuBrPMDETA

rt

FF

FF

F

N3

FF

F

FF

(1)

(1)

(2)

(2)

(3)

(3)

(4)








d119872119899theo






3




2OH and ndashCH

2O protons



2protons using the

following [38]


[(11198872) + (11198863)]times 100 (1)


Tran

smitt

ance

(au

)


4000 3000 2000 1000






2protons between









119892of P(HEMA(20)-co-MMA(80))




CH2

CH3 CH3

C Cc cx y

O OO

OH

OaCH3

H2H2

H2C

a

bb

c

c

40 30 20 10

(a)


a

bc

40 30 20 10

(b)


a

bc

40 30 20 10

(c)


abc

40 30 20 10

ppm (t1)

(d)









c119872119899theo

d119872119908119872119899
















(∘C)


∘C)


2(wt)


70 60 50 40 30 20 10

O

HO

O

O O OOO O

O

Bra b c

c

d e

f g

h i

j

k

l m

n

n

CH3

x y z

b g l

f

j m

n

k

d h

a c e i

ppm (t1)


180

182

184

186

188

190

192

194

196

198

200

202

204205

0 20 40 60 80 100 120 140 160 180

Temperature (∘C)





Hea

t flow

endo

dow

n (m

W)


= 0248 Jglowast∘C

= 0198 Jglowast∘C

ΔCp

ΔCp





16

18

20

22

24

26

28

30

32

minus40 minus20 0 20 40 60 80 100 120 140 160 180

Temperature (∘C)

Hea

t flow

endo

dow

n (m

W)





100

80

60

40

20

0

0 200 400 600 800

Wei

ght (

)

Temperature (∘C)






C HTr

ansm

ittan

ce (a

u)

4000 3000 2000 1000



(a)

Tran

smitt

ance

(au

)

4000 3000 2000 1000


C H


(b)



119899values





3in DMF





4000 3500 3000 2500 2000 1500 1000 500

3Tr

ansm

ittan

ce (a

u)



mdashN


80 70 60 50 40 30 20 10

ppm (t1)

O

O

OO

OO O

O OO Ox y z

Br

F

FF

F

F

NN

N

f

f

e

e

CH3

CH2

n

CH


4 Conclusions



Click product


ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)



119899= 112620 (PDI = 158)





Acknowledgment


References























































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






d119872119899theo






3




2OH and ndashCH

2O protons



2protons using the

following [38]


[(11198872) + (11198863)]times 100 (1)


Tran

smitt

ance

(au

)


4000 3000 2000 1000






2protons between









119892of P(HEMA(20)-co-MMA(80))




CH2

CH3 CH3

C Cc cx y

O OO

OH

OaCH3

H2H2

H2C

a

bb

c

c

40 30 20 10

(a)


a

bc

40 30 20 10

(b)


a

bc

40 30 20 10

(c)


abc

40 30 20 10

ppm (t1)

(d)









c119872119899theo

d119872119908119872119899
















(∘C)


∘C)


2(wt)


70 60 50 40 30 20 10

O

HO

O

O O OOO O

O

Bra b c

c

d e

f g

h i

j

k

l m

n

n

CH3

x y z

b g l

f

j m

n

k

d h

a c e i

ppm (t1)


180

182

184

186

188

190

192

194

196

198

200

202

204205

0 20 40 60 80 100 120 140 160 180

Temperature (∘C)





Hea

t flow

endo

dow

n (m

W)


= 0248 Jglowast∘C

= 0198 Jglowast∘C

ΔCp

ΔCp





16

18

20

22

24

26

28

30

32

minus40 minus20 0 20 40 60 80 100 120 140 160 180

Temperature (∘C)

Hea

t flow

endo

dow

n (m

W)





100

80

60

40

20

0

0 200 400 600 800

Wei

ght (

)

Temperature (∘C)






C HTr

ansm

ittan

ce (a

u)

4000 3000 2000 1000



(a)

Tran

smitt

ance

(au

)

4000 3000 2000 1000


C H


(b)



119899values





3in DMF





4000 3500 3000 2500 2000 1500 1000 500

3Tr

ansm

ittan

ce (a

u)



mdashN


80 70 60 50 40 30 20 10

ppm (t1)

O

O

OO

OO O

O OO Ox y z

Br

F

FF

F

F

NN

N

f

f

e

e

CH3

CH2

n

CH


4 Conclusions



Click product


ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)



119899= 112620 (PDI = 158)





Acknowledgment


References























































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





CH2

CH3 CH3

C Cc cx y

O OO

OH

OaCH3

H2H2

H2C

a

bb

c

c

40 30 20 10

(a)


a

bc

40 30 20 10

(b)


a

bc

40 30 20 10

(c)


abc

40 30 20 10

ppm (t1)

(d)









c119872119899theo

d119872119908119872119899
















(∘C)


∘C)


2(wt)


70 60 50 40 30 20 10

O

HO

O

O O OOO O

O

Bra b c

c

d e

f g

h i

j

k

l m

n

n

CH3

x y z

b g l

f

j m

n

k

d h

a c e i

ppm (t1)


180

182

184

186

188

190

192

194

196

198

200

202

204205

0 20 40 60 80 100 120 140 160 180

Temperature (∘C)





Hea

t flow

endo

dow

n (m

W)


= 0248 Jglowast∘C

= 0198 Jglowast∘C

ΔCp

ΔCp





16

18

20

22

24

26

28

30

32

minus40 minus20 0 20 40 60 80 100 120 140 160 180

Temperature (∘C)

Hea

t flow

endo

dow

n (m

W)





100

80

60

40

20

0

0 200 400 600 800

Wei

ght (

)

Temperature (∘C)






C HTr

ansm

ittan

ce (a

u)

4000 3000 2000 1000



(a)

Tran

smitt

ance

(au

)

4000 3000 2000 1000


C H


(b)



119899values





3in DMF





4000 3500 3000 2500 2000 1500 1000 500

3Tr

ansm

ittan

ce (a

u)



mdashN


80 70 60 50 40 30 20 10

ppm (t1)

O

O

OO

OO O

O OO Ox y z

Br

F

FF

F

F

NN

N

f

f

e

e

CH3

CH2

n

CH


4 Conclusions



Click product


ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)



119899= 112620 (PDI = 158)





Acknowledgment


References























































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







(∘C)


∘C)


2(wt)


70 60 50 40 30 20 10

O

HO

O

O O OOO O

O

Bra b c

c

d e

f g

h i

j

k

l m

n

n

CH3

x y z

b g l

f

j m

n

k

d h

a c e i

ppm (t1)


180

182

184

186

188

190

192

194

196

198

200

202

204205

0 20 40 60 80 100 120 140 160 180

Temperature (∘C)





Hea

t flow

endo

dow

n (m

W)


= 0248 Jglowast∘C

= 0198 Jglowast∘C

ΔCp

ΔCp





16

18

20

22

24

26

28

30

32

minus40 minus20 0 20 40 60 80 100 120 140 160 180

Temperature (∘C)

Hea

t flow

endo

dow

n (m

W)





100

80

60

40

20

0

0 200 400 600 800

Wei

ght (

)

Temperature (∘C)






C HTr

ansm

ittan

ce (a

u)

4000 3000 2000 1000



(a)

Tran

smitt

ance

(au

)

4000 3000 2000 1000


C H


(b)



119899values





3in DMF





4000 3500 3000 2500 2000 1500 1000 500

3Tr

ansm

ittan

ce (a

u)



mdashN


80 70 60 50 40 30 20 10

ppm (t1)

O

O

OO

OO O

O OO Ox y z

Br

F

FF

F

F

NN

N

f

f

e

e

CH3

CH2

n

CH


4 Conclusions



Click product


ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)



119899= 112620 (PDI = 158)





Acknowledgment


References























































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




C HTr

ansm

ittan

ce (a

u)

4000 3000 2000 1000



(a)

Tran

smitt

ance

(au

)

4000 3000 2000 1000


C H


(b)



119899values





3in DMF





4000 3500 3000 2500 2000 1500 1000 500

3Tr

ansm

ittan

ce (a

u)



mdashN


80 70 60 50 40 30 20 10

ppm (t1)

O

O

OO

OO O

O OO Ox y z

Br

F

FF

F

F

NN

N

f

f

e

e

CH3

CH2

n

CH


4 Conclusions



Click product


ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)



119899= 112620 (PDI = 158)





Acknowledgment


References























































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




Click product


ppm (t1)

(a)

o

o

o

p

p

m

m

m


ppm (t1)

F

FF

F

FN3

(b)



119899= 112620 (PDI = 158)





Acknowledgment


References























































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials












































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



research article synthesis of fluorinated amphiphilic block ...synthesis of uorinated amphiphilic...

Documents