macromolecular chemistry s112003 -...

Supporting material for students registered to subject:

Macromolecular chemistry S112003

Teacher: Jan Merna, Department of Polymers, Institute of Chemical Technology ,Prague

Lecture authored by Jan Merna is licensed under a Creative Commons Attribution-

NonCommercial-NoDerivs 3.0 Unported License

Sources:

Prokopová I.: Makromolekulární chemie, VŠCHT Praha, 2007. (educational text in Czech)

Merna J.: Polymers Instantly, educational text in English, freely accessible from

http://merna.eu/teaching/macromolecular-chemistry/

Encyclopedia of Polymer Science and Technology, J.Wiley Sons, Interscience, Publ., New York, 1964-1991

merna@vscht.cz, B130

Lectures + exercises (2+1)

Recommended literature:•Stevens M.P.: Polymer Chemistry� An Introduction. Oxford University Press, Inc.,

New York 1999.

•Chanda M.: Introduction to Polymer Science and Chemistry. A Problem Solving

Approach. CRC Press Boca Raton 2006.

•Young R.J., Lovell P.A.: Introduction to Polymers. Third Edition. CRC Press Boca

Raton 2011.

Supporting materials: http://merna.eu/teaching/macromolecular-chemistry/

Evaluation:

written tests:

•One test in the mid of semester•Final exam test

MACROMOLECULAR CHEMISTRY

Outline of the course:

1. Basic terms, history, nomenclature

2. Structure of macromolecules, molecular weight.

3. Molecular structure and properties of polymers.

4. Polymerizability of low molecular substances.

5. Free radical polymerization - elemental reactions.

6. Kinetics of free radical polymerization.

7. Free radical copolymerization.

8. Ionic polymerization and copolymerization.

9. Insertion polymerization, polymerization practice.

10.Ring-opening polymerization.

11.Step-growth polymerization - characterization, reactivity of

monomer functional groups.

12.Polycondensation - mechanism and kinetics, molecular

weight distributions.

13.Polyadditions - typical syntheses.

14.Reactions of polymers.

(1838) polyvinylidenchloride

(1839) polystyrene ?

1820 processing of natural rubber

1839 rubber vulcanization

1862 celluloid- nitrocellulose+camphor

1897 Galalith - casein (milk protein) and formaldehyde

HISTORY OF MACROMOLECULAR CHEMISTRY

1906 Bakelite – phenol-formaldehyde resin

1915 „methyl-rubber “ - poly(dimethylbutadiene)

1926 – 1939 alkyd resins, aminoplastics, polymethylmethacrylate, polybutadiene, polyvinylacetate, polystyrene, polyvinylchloride, polyethyleneoxide, polychloroprene, unsaturated polyesters, polyizobutylene, butadiene-styrene rubber, polyamide 66

1939 – 1945 polyvinylidenchloride, PE (LD), polyamid 6, polyurethanes, polyakrylonitrile, silicons

1946 – 1955 epoxides, polytetrafluorethylene, polyethylenterephtalate, polycarbonates, PE (HD)

1956 – 1965 polybutadiene (cis-1,4), polypropylene, polyformaldehyde,aromatic polyamides, block copolymers Sty-Bu-Sty

HISTORY OF MACROMOLECULAR CHEMISTRY

Fathers of macromolecular chemistry

Wallace Carothers (1896-1937)Hermann Staudinger (1881-1965), NP 1953

Paul J. Flory (1910-1985), NP 1974

theory of polycondensation

solution and solid phase polymer properties,

theory of crosslinkingKarl Ziegler Giulio Natta, NP 1963

1950

1960

1970

1980

1990

2000

2010

0 2 4 6 8

Year

Nobel prices in polymer science

Natta & Ziegler

Heeger & MacDiarmid

& Shirakawa

Polymer production worldwide

300 Mt/year (7% of oil)

1. PE 80 Mt/y

2. PP 50 Mt/y

3. PET 50 Mt/y

4. PVC 30 Mt/y

5. PS-styrene polymers

Rubbers- 20 Mt/y

Price of basic polymers

1-2 €/kg

Age of plastics

Polymers advantages and role in today‘s society:

•Low density•Cheap manufacture and sources•Easy processing•Insulation properties-thermal+electro

•Polymers save more energy than used for their production(buildings, transportation)•Food protection•Fabrics-synthetic fibres-save land, fertilizers, water

Utilization of plastics in Europe:

Plastics classification:

•Consumable (commodity)_PE,PP,PS, PVC, PET

•Engineering (construction) plastics-better properties

•Special (high-performance)P

ric

e +

pe

rfo

rma

nc

e

Pro

du

cti

on

vo

lum

e (

t/y)

Thermoplastics classification

Special

Engineering

Commo

dity

Plastics recycling in Europe

polymer ( macromolecular compound)

Oligomer

monomer

polymerization

polyreaction

step-growth

chain-growth

ring-opening

regular (irregular) polymer

constitutional unit

Constitutional repeating unit (CRU)

Monomeric unit (mer)

Polymerization degree

Copolymer

Basic terms

CH2 CH

Amonomer

polyreactionCHCH2 CHCH2 CH2 CH

A A ARegular polymer

CHCH2 CH2 CH2CHCH

AAAIrregular polymer

CHCH2

A

CH2CH

A

Repeating constitutional units (CRU)

,CH2

constitutional unit

CH

A

CHCH2 CH2

A

CHCH2 CH2

A

,, , ...

n

CH2 CH2CH2 CH2

monomer (ethylene) Polyethylene with degree of polymerization n

CRUCH2

Monomeric unitCH2CH2

Basic terms

IUPAC. Pure Appl. Chem. 84, 2167–2169 (2012).

Polymer nomenclature

PRINCIPALS OF STRUCTURE BASED POLYMER NOMENCLATURE

The order of subunit seniority in preferred CRU: 1. heterocycles

2. heteroatoms3. C-cycles4. C-chains

Naming of pref. CRU: listing of names of largest possible subunits

CRU usually divalentC atom with double bond have the lowest locant number

free valences in C-cycles – lowest locant numbers

• Choice of preferred CRU

• Naming of CRU (according to nomenclature rules of org. chem.)

• prefix poly-

Polymer nomenclature

>

1. podjednotka s největším počtem kruhů

poly(4,2-pyridindiylimino-1,4-phenylene-benzylidene)

N NNHNH CH CH

Hierarchy of heterocyles

More unsaturated (less hydrogenated) unit is favoured

Hierarchy of heteroatoms

O,S, Se, Te, N, P, As, Sb, Bi, Si, Ge, Sn, ….

Hierarchy of C-cycles

1. Subunit with largest amount of cycles

>

2. podjednotka s největším individ. kruhem

>

3. podjednotka s největším počtem atomů společných dvěma cyklům

> >

5. podjednotka nejméně hydrogenovaná

4. podjednotka s nejnižšími čísly lokantů v prvním rozdílném bodě

spojení kruhů

10a

>

8a

5a

1

2

3456

7

8

9 10

1 2

3

4

10

56

7

8

98a

2. Subunit with the largest individual ring

3. Subunit with the highest number of common atoms between two cycles

4. Subunit with the lowest number of locants in first different point of cycles connection

5. The most unsaturated cycles is the most preferred

Substituents

n

CH2CH

BrCl

1 3

5

2

46

a) Included to trivial name of subunitb) Named using prefixes joined to the name of corresponding subunit

poly[(6-chlorocyklohex-1-ene-1,3-diyl)(1-bromoethylene)]

poly[(6-chlorocyklohex-1-ene-1,3-diyl)(1-bromoethanediyl)]

Functional derivatives as a part of CRU

as substituents ad b)

poly[oxy(2-methoxycarbonyl)ethane-1,1-diyl]

- chemical

constitution

- type and arrangement of structural units - molar mass

configuration

conformation

- physical

mutual arrangement of macromolecules

2. STRUCTURE OF POLYMERS

1. Constitution

Monomer with functionality two : linear polymers (a)

Monomer with functionality two or higher : branched (b)

crosslinked polymers (c)

(a) (b) (c)

Types of enchainment of monomer units

R

CH CH2

CH2

RHCR R

CH CH2 CH CH

2

CH2

R

CH CH2

R R

CHCH CH2

Connection head to tail

Connection tail to tailResp. head to head

Modes of monomer units connection for conjugated diene

polymerization

1

2

3

4

2-methylbuta-1,3-diene isoprene

1

4

12

34

1,2-addition

1,4-addition

n

3,4-addition

Non-symetrical substituted diene: isoprene

symmetrical diene: butadiene

CH2CH2 CH CH

CH2CH2 CH CH

CH2

CH2 CH

CH

1,4 - addition

1,2 - addition

(the same as 3,4-addition)

Special macromolecular architectures

Grafted-copolymercomb

star

dendrimer

ladder

cyklic

polycatenane

polyrotaxane

Copolymers:

statistical

alternating

block

grafted

Reasons for spatial isomers:

a) tetrahedral arrangement of substituents on asymmetrical carbon atom

zig-zag conformation of polyethylene

2. Macromolecules configuration

Reasons for spatial isomers :

b) Planar arrangement of substituents on carbon atoms connected by double bond

cis isomers

trans isomers

- arrangement (sequence) of stereoisomeric centers

Atactic polymer

R RR R RR

isotactic polymer syndiotactic polymer

Polymer tacticity

Ditactic polymers

erythro-diizotactic threo-diizotactic

erythro-disyndiotactic threo-disyndiotactic

R H H HRR R

H H H

H

HR RH H

H H

H H

H H

R R R,

R,

R,

R,

R,

R,

R,

R,

Ditactic polymers

R H H H HR R

H H H H

R

H

R

H H H H H H H

R R R

R,

R,

R,

R,

R,

R,

R,

R,

erythro-diizotactic threo-diizotactic

erythro-disyndiotactic threo-disyndiotactic

synperiplanar (sp) antiperiplanar (ap)conformation conformation

3. Molecule conformation

Ethane

sp ap

H

H

H

H

H

H

HH

HH

HH

H H

H

H H

H

H H

H

H

H

H

Angle of rotation

180°sp

-180°sp

-120°ap

-60°sp

0°ap

60°sp

120°ap

Potentialenergy

Molecule conformation

Butane

least probable! !

Rotational movement of atoms in polymer chain

1

2

3

4

5

Free rotation is restricted by stericbarriers and by interaction with neighbor macromolecules

Chain segment

rotating part of chain (between nodes)

Dimensions of macromolecular coil

rmax

r = 0

oo

r opt

Average end-to-end distance

ideal chain (freely-jointed chain)

Polymer: mixture of polymerhomologues – nonuniform polymer

n1, n2, ...ni – number of molecules

M1, M2, ...Mi – molar mass of molecules

Types of average molar mass of polymers

- number

- mass (weight)

- viscosity

- z-average

ii

i

iin Mx

n

MnM

ii

ii

2

iiw Mw

Mn

MnM

a

1a

iiv MwM

ii

2

ii

2

ii

3

iiz

Mw

Mw

Mn

MnM

Molar mass of polymers

Uniform polymer: all macromolecules are of the same size

Relationships between molar mass averages:

zwn MMM

zwn MMM

< <

Uniform polymer

Non-uniform polymer

Analogy of polymer molar mass

498 pcs à 1 kg = 498 kg2 pcs à 250 kg = 500 kg

500 pcs 998 kg

400 pcs à 1 kg = 400 kg100 pcs à 6 kg = 600 kg500 pcs 1000 kg

kg1,9962498

kg250)x21x(498Mn

kg2,00

100400

kg6)x1001x(400Mn

kg125,75250x21x498

kg)250x21x(498M

22

w

kg4,00

6x1001x400

kg)6x1001x(400M

22

w

-the relationship between the number of moles of each polymer species (ni) and the molar mass (Mi) of that species

Am

ou

nt

of

poly

mer

Mol. mass

nM

wM

zM xi

0Mol. mass

Distribution of polymer molar mass

Methods of molar mass determination

Mn: osmometry, ebulioscopy, cryoscopy, determination of end-groups

Mw: light scattering

Mv: viscometry

Determination of molar mass distribution:

Size exclusion chromatography-SEC (gel permeation chromatography-GPC)PS calibration x absolute detection

Separation mechanism of SEC