synthesis and properties of hydrophobic starches · 59. starch convention; detmold, april 16-17,...

Synthesis and Properties of HydrophobicStarches

Waltraud Vorwerg, Kay Hettrich, Sylvia Radosta

59. Starch Convention; Detmold, April 16-17, 2008

59. Starch Convention; Detmold, April 16-17, 2008 2

Outline

• Introduction

• Synthesis of starch esters-Alkenylsuccinate starch-Ester with fatty acid chlorid

• Synthesis of starch ethers-Benzylated starch-Epoxidised triglycerides-Glycidic ethers – bi- and trifunctional

• Amphiphilic starch

• Investigation of application

• Summary


Potentially technical applications of starch derivatives require improved resistanceto diffusion and penetration of water.

The general concept of “water resistant starch” are classified according the application areas or properties:

• Modified Starch is utilised to improve the sensitivity of textile fibre against wetnessby reinforcement of bonds between fibres

• Modified Starch is applied as water-repellent (hydrophobic) agent reducingpenetration of moisture

• Application fields: Surface sizing in paper making, adhesive for paper and corrugated board , textile sizing and finishing

Stability against high humidity of air and penetration of waterDesire

Introduction


Synthesis of esters – Alkenyl succinate starch

Octenyl succinate starch

OSAStarch +

OO O

O

HOO

OH

HO O

HOO

OH

O

HOO

OH

O

O

HOO

OH

HOO

HOOC

T, Solventcatalyst

- H2O Succinic acid derivatives:

OSA: Octenyl-DDSA: Dodecenyl-LASAR: Alkenyl- (C16-C18)


Synthesis of esters – Alkenyl succinate starch

• reagent yield between 50 und 90%

• reaction efficiency is increasing according the followingconditions:

- efficiency of reagent: OSA >> DDSA > ASA- homogeneous state of swelling of the starch during reaction- high ratio of starch : water- NaOH is more suitable than Na2CO3

- reaction temperature between 40-70°C

• molecular degradation is limited at pH 8-10


Ester with long alkyl chains

O

Cl

- H2O, - Na+, - Cl-

1. 2.5 M NaOH

2. O

HOOOH

HO O

HOOOH

O

HOOOH

O

O

HOO

OH

HO O

Starch

DS: 0,06...0,15

Advantage: - quick reaction

Disadvantages: - hydrolysis of reagent

- unavailability of commercial chlorides of fatty acids

Fatty acid chlorides:- Octanoyl chlorid- Polymergin acid chloride


10-2 10-1 10010-3

10-2

10-1

100

G',

G''

[Pa]

Frequency [Hz]

HS-21 G' HS-21 G'' HS-34 G' HS-34 G''

measuring temp. 60 °C

104 105 106 107 1080.0

0.2

0.4

0.6

0.8

dW/d

(log

M)

Molar mass [g/mol]

d.s. MW[106g/mol] HS-15 0,15 2.43 HS-21 0,025 2.86 HS-34 0,045 2.87

Molar mass distribution

Ester with Octanoyl and Polymergin acid

Dynamic rheology


Principle: Benzylation (DS 0,1 ... 0,25)

1 10 1000

5

10

15

20

25

30

Vol

ume

(%)

Particle size (µm)

hydrophobic dispersion

Jet-coker

Dispersion with stable viscosity

native potato starch

Sedimentation

Change of distribution of particle size by pressure cooking

H H

O

HO

H

O

H

OH

OH

CH2 OH

+Cl

- HCl

OHCH2

O

HO

H

O

H

HO

O

HH

Synthesis of ethers – benzyl starch


Ethers with epoxidised triglycerides

O

HOO

OH

HO O

HOO

OH

O

HOO

OH

O

O

HOO

OH

HO

+ Starch+ OH-

O

O

O

C

C

C CH

CH

CH

CH

CH

CH

R

H2C

HC

HC

H2C R

OO

O

O OR

OO

R'

- Autoklave

- Temperature: 120 bis 160°C

- NaOH, H2O, Na2SO4

Bien et al. 2001


Ethers of triglycerides with linseed and soy been oil

Components: linseed oil soy been oil

• linolenic acid 52% 8%

• linoleic acid 17% 56%

• oleic acid 22% 21%

• stearic acid 4% 4%

• palmitic acid 5% 10%

Lein: Edenol B 316 (Fa. Cognis), ELO (Fa. Hobum)Soja: Edenol D81 (Cognis), ESBO u. EME (Hobum)

Composition


Molecular composition of ethers with triglycerides

different molecular degradationby applied synthesis conditions

104 105 106 107 1080,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

dW

/d(lo

g M

)

Molar mass [g/mol]

MW[106g/mol] HS-20 3.61 HS-23 8.68 HS-25 2.38 HS-30 3.16 HS-14 2.64 HS-17 8.92

*methyl ester

Kind of oil DS Mw[106 g/mol]

Soy (HS-14) 0,06 2,64

Soy (HS-20) 0,03 3,61

Soy (HS-25)* 0,01 2,38

Soy (HS-30) 0,03 3,16

Lin (HS-17) 0,05 8,92

Lin (HS-23) 0,02 8,68


Flow behaviour of ethers with triglycerides

100 101 102

10-2

10-1

100

Visc

osity

[Pa·

s]

Shear rate [1/s]

HS-14 HS-17 HS-20 HS-23 HS-25 HS-30

measuring temperature: 60°C

Viscosity is not dependent on kind of epoxidised triglyceridebut more on the degree of substitution, synthesis conditions respectively swelling state inaqueous solution.


OO

OO CH3

CH3

OO

O

O

GE11: Cyclohexandimethanol-diglycidic ether GE14: Neopentylglycol-diglycidic ether

CH3

OO

O

O

n, n=4-6

GE19: Polypropylenglycol-diglycidether

Synthesis with glycidic ethers - bifunctional


100 101

10-1

100

101

Visc

osity

[Pa·

s]

Shear rate [1/s]

Corn starch GE11 GE14 GE19

measuring temperature 80°C

Synthesis with glycidic ethers - bifunctional

10-1 100 101 102 10310-2

10-1

100

101

102

103

G',

G''

[Pa]

Shear stress [Pa]

Corn starch G' Corn starch G'' GE11 G' GE11 G'' GE14 G' GE14 G'' GE19 G' GE19 G''

measuring temperatre 20°C

Flow behaviour Stress sweep


GE9: Polyglycerol-triglycidic ether GE12: Glycerin-triglycidic ether

OO

OO

O

O

n, n=3-6

O

O O

O

O

O

Synthesis with glycidic ethers - trifunctional


4x100 6x100 8x100 101

10-3

10-2

10-1

Visc

osity

[Pa·

s]

Shear rate [1/s]

Maisstaerke GE12 GE9


Synthesis with glycidic ethers - trifunctional

10-2 10-1 100 101 102

10-3

10-2

10-1

100

101

102

G',

G''

[Pa]

shear stress [Pa]

Corn starch G' Corn starch G'' GE12 G' GE12 G'' GE09 G' GE09 G''

Flow behaviour Stress sweep


Amphiphilic starch with hydrophobic Quab

Cl OH

N+

CH3

CH3

RCl-N+

CH3

CH3

RCl-

O

- H2O, - Cl-

+ OH-

O

HOO

OH

HO O

HOO

OH

O

HOO

OH

O

O

HOO

OH

HO

N+CH3

H3C R

Quab

+ Starch(OH-)

HO

R: Dodecyl- (Quab 342),Cocoalkyl- (Quab 360),Stearyl- (Quab 426)

Müller, Gruber et al. 2000

Amphiphilic starch


• Heterogeneous or homogeneous reaction in dependence on thetype of material

• Reaction temperature 40 bis 80°

• advantage: short time of reaction

• disadvantage : surfactant properties of reagents

• Potential of application: Paper additiv, adhesive und textil sizingreplacement of polyacrylate



104 105 106 1070.0

0.2

0.4

0.6

0.8

dW/d

(log

M)

Molar mass [g/mol]

MW[106g/mol] Quab342 3.74 Quab360 3.89 Quab426 5.67

10-2 10-1 10010-5

10-4

10-3

10-2

10-1

100

101

102

G',

G''

[Pa]

f requency [Hz]

Quab342 G' Quab342 G'' Quab360 G' Quab360 G'' Quab426 G' Quab426 G''



Molar mass distribution Frequency sweep


Investigation of application

Surface sizing of paper

• Application of aqueous

starch dispersion with size

press

• Defined method for water

adsorption – Cobb60 test

• Inkjet-printability – ink

density, ink penetration

• Contact angle

before sizing

after sizing


OSA Quab 342 Quab 360 Quab 426 Octanoyl Polymerg. Epoxylipid0

10

20

30

40

50

60

70

Cob

b 60-V

alue

Starch derivative

Degree of substitution

OSA 0,07

Quab 342 0,03

Quab 360 0,02

Quab 426 0,02

Octanoyl 0,07

Polymergin acid 0,06

Epoxy triglyceride 0,02

Hydrophobic starch - Cobb60-Value

Dr. K.L. Woll, Emsland-Stärke GmbH


Investigation of water penetration

• Starch on copper sheet

• droplet of water ca. 20 µl

• needle touches the surface of the film

• Measurement of resistance between copper sheet and pin in dependence on time

• resistance is high at the start and breaks down when the drop of water has penetrated the film.

• Advantage: quick and easy method with small portions of the film sample.

St. Kröpke, A. Holländer (IAP)

Determination of the velocity of water penetration

Ω

Ω

water dropletfilm

copper sheet

needle


0 60 120 180 240-0,7

-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

d, µm t, s OSA (1. measurem.) 106 104 OSA (2. measurem.) 122 114 OSA (3. measurem.) 116 121 calculated curve 1. Determination of time

Time, s

Volta

ge, V

OSA Starch Different hydrophobic starches

0

50

100

150

200 Epoxi Lasar OSA OSA OSA Epoxi Epoxi Epoxi Quab Epoxi Epoxi Octanoyl

Tim

e [s]

Thickness of the f ilm layer 100µm

Hydrophobic Starch - water penetration


100 %

10 % 1 %100 %

100 %100 %

Density D = -log b b = Reflexion

b = reflected light/emitted lightD = log 1/b

b = 1,0 b = 0,1 b = 0,01

D = 0 D = 1,0 D = 2,0 Papier

Hydrophobic starch – inkjet printing



1,5640,02Epoxy tryglyceride

2,1480,06Polymergin

1,6290,07Octanoyl

2,4200,02Quab 426

2,3200,02Quab 360

2,5170,03Quab 342

2,7170,07OSA

Colour densityCobb60-ValueD.S.Kind of derivative

Effects of hydrophobic starches in surface sizing



• Hydrophobic reagents with different chemical structure are suitable for the modification of starch influencing surface properties of paper.

• Reaction efficiency is dependent on the kind of reagent; e.g. anhydride or epoxid, length of alkylene chains and the presence of phenyl groups.

• Optimized reaction conditions cause only low molecular degradation of the starch and guarantee film forming properties.

• The degree of substitution (0.02 – 0.5) is dependent on starch type or derivative.

• The hydrophobization of starch can be combined with ionic ethers to develop amphiphilic starch products.

Hydrophobic starch - conclusions


• Financial support: Agency for Renewable Recources/ BMELV

• Co-workers of IAP

Dr. Kay Hettrich Stephan LangDr. Sylvia Radosta Gabriela Reimer Dr. Andreas Ebert Marion Stage Matthias Nenneker Barbara BrettnacherStefan Kröpke Dr. Andreas Holländer

• Industry partner: Emsland-Stärke GmbH, Hobum Fettchemie, UPPC AG

Acknowlegement


Contact address:

Dr. Waltraud VorwergWissenschaftspark GolmGeiselbergstraße 6914476 Potsdam-Golm

phone: +49/331-568-1609e-mail: [email protected]

synthesis and properties of hydrophobic starches · 59. starch convention; detmold, april 16-17,...

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