Starch Based PolyurethanePresenter

Muhammad Minhas Azeem

7616

Dept. Applied Chemistry & Biochemistry

Government College University Faisalabad

Polyurethane

Starch

Starch based polyurethane

Advantages

Applications

Drawbacks

References

Polymers are broadly classified into:

Synthetic Polymers: Obtained by polymerization of petroleum based raw materials.

Natural Polymers: Obtained from different renewable resources

Polyethylene

Polypropylene

Polytetrafluoroethylene (Teflon®)

Polyvinylchloride

Polyvinylidenechloride

Polystyrene

Polyvinylacetate

Polymethylmethacrylate (Plexiglas®)

Polyacrylonitrile

Polybutadiene

Polyisoprene

Polycarbonate

Polyester

Polyamide (nylons)

Polyurethane Polyimide

Polyureas

Polysiloxanes

Polysilanes

Polyethers

It is formed by the condensation polymerization of adiisocyanate and polyol or dialcohol. The polymer chain islinked by urethane groups (–O–CO–NH–).

The NCO group of the diisocyanate can react with –OH group toform NCO terminated PU prepolymer, which can be furtherreacted with diol or diamine to form final polyurethane.

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Polyurethane foam is used for the thermal insulation.

If Polyurethane based fine threads combine with nylon then prepared light weight stretchable garments.

Polyurethane is used in all parts of the automobiles for example in seats, doors, windows and tires.

Polyurethane Soft solid elastomers are used for gel pads and print rollers

Under the effect of high beam radiations, It emits toxic fumes, greenhouse gases.

Synthetic PU may cause some health problem such as allergic reactions, difficulty in breathing.

Most of the PU are biocompatible and some are not.

PU are not significantly degradable

Polyurethane based products are more expansive as compared to other materials.

The drawbacks of the polyurethane polymerscan be overcome by the incorporation ofnatural polymer into the backbone of syntheticpolymer. The resulting material will havebetter mechanical, thermal properties, lowlevel of toxicity, biodegradable, eco friendlyand biocompatible.

• Polyesters– Polylactic acid– Polyhydroxyalkanoates

• Proteins– Silk– Soy protein– Corn protein (zein)

• Polysaccharides– Xanthan– Gellan

– Starch– Chitin– Chitosan– Cellulose– Alginate

• Polyphenols– Lignin– Tannin– Humic acid

• Lipids– Waxes– Surfactants

• Specialty polymers– Shellac– Natural rubber– Nylon (from castor oil)

Starch is the principal carbohydratestorage product of plants

Starch is consists of two types ofmolecules.

(i) Linear amylose (20 to 25%)

(ii)Branched amylopectin (75 to80%)

It contain large number of glucose

monomers linked through α (1, 4)

and α (1, 6) glycosidic bonds.

Starch is extracted primarily from corn;with lesser sources being potatoes, rice,barley, sorghum, and wheat

Forthcoming slides will give you an overview about different sources of starch.

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Starch based polyurethane are usually formed bythe copolymerization of thermoplastic starch andthermoplastic polyurethane.

Poly-addition (a type of condensationpolymerization) reactions are preferred in theformation of Starch based polyurethane becauseno by-products are formed.

The reaction rate of starch urethanizationdepends on the nature of the reaction medium,the kind of isocyanate and the temperature used.

Barikani and Mohammadi (2007) synthesized abiodegradable polymer. Prepolymer wasprepared by addition of HDI intopolycaprolactone diol. The resultant product isobtained is NCO terminated prepolymer.

Starch Based Polyurethane

Preparation of polycaprolactone based prepolymer

Preparation of Starch based Polyurethane

FT-IR spectra of prepolymer with Capa225 and HDI a) Capa, b) prepolymer

FT-IR spectra of (a):Starch,(b): Starch Modified Polyurethane32

The variation of contact angle with % of grafted prepolymer on starch

contact angle(q)ºPrepolymer on starch

(%)

Sample no.

00Starch

8721

8852

91103

105174

107255

M. Barikani *, M. Mohammadi Carbohydrate Polymers, 68 (2007) 773–780

It can be observed that hydrophobicity increases with increasing amount of prepolymer

(b) (c)

SEM micrographs of (a): Starch, (b): Starch modified urethane ;( sample no.3), (c): (sample no. 5)

The scanned surface reveals that starch granules were completely covered by polyurethane.

This criteria confirms the strong adhesion between the polyurethane and starch granules.

A.L. Da Roz et al(2009) synthesized the cross-linked starch based PU.

PPO/TDI based PU prepolymer

+ Starch swollen in DMSO,

+DBTDL as catalyst.

The hydrophilicity of the modified sample was decreased.

Chemically modified sample has amorphous structure.

The cross linking produced the change in the morphology of the starch.

Yongshang Lu et al (2005) synthesized plasticized starch basedwaterborne polyurethane.

First of all rapeseed oil was epoxidized to form epoxidizedrapeseed oil and after some chemical modification rapeseedoil polyol was prepared.

The prepared polyol was dispersed with IPDI in the presenceof DMPA and TEA to form water borne PU dispersion. Thenthermoplastic starch which is obtained from wheat was mixedwith the PU dispersion.

Rapeseed oil

CH3 CH2 HC CH CH2 CH CH CH2 CO2 CH2

CH

CH2

CH3 CH2 CH CH CH2 CO2

CH2 CO2CH3 CH2 HC CH

4 7

77

117

CH2 HC CH CH2 CH CH CH2 CO2 CH2

CHCH3 CH2 CH CH CH2 CO2

CH2 CO2

O

CH2 HC CH

O

CH3

CH2CH3

4 7

77

117

HCL

Epoxidized rapeseed oil

CH3 CH2 HC CH CH2 CH CH CH2 CO2 CH2

CH2

CH3 CH2 CH CH CH2 CO2

CH2CH3 CH2 HC CH

Cl

OH

OH

Cl

CH

CO2

4 7

77

117

Rapeseed oil polyol

OUTCOME OF THE STUDY

Contact angle is increased

Tensile strength is increased from 2.8 to 4.1 Mpa

Elongation at break is increased from 84 to 480 %

Toughness is increased from 1.8 to 7.1 MPa

Youngshang Lu et al (2005) modified the TPS withWPU

Castor oil, IPDI and DMPA based PU prepolymer

Starch, glycerol and water (70:20:10) based TPS

TPS was blended with PU prepolymer to formed

starch based polyurethane

OUTCOME OF THE STUDY

Hydrophobic character is increased

Water absorption and swelling are decreased

Contact angle is increased from 34º to 63º

Young’s modulus is increased from 40 to 75MPa

Yixiang Wang et al (2010) synthesized the WPU compositereinforced with SN and CW.

PPG and TDI based WPU matrix SN and CW are used as reinforcement

The mechanical properties of the composite increased byincorporation of the nanofillers such as

Tensile strength is increased 252% Elongation at break is increased 136% Young’s modulus is increased 135%

Xiaodong Cao et al (2008) modified the PS with

poly(ε-caprolactone) based WPU.

PCL, IPDI and DMPA based prepolymer Starch, glycerol and water(7:3:90) were used to form PS

OUTCOME OF THE STUDY

Amorphous character is increased Hydrophobicity is increased Tensile strength is increased from 2.4 to 3.9 MPa Elongation at break is increased from 35% to 886%

Seung-kyu Ha et al(2002) synthesized theblend of polyurethane and starch granules.

PCL and MDI based prepolymer

+ Starch granules

+ DBTDL catalyst

OUTCOME OF THE STUDY

Tg is increased

Swelling character is decreased

Mechanical properties are also increased

MODIFICATION OF PU BY INCORPORATING STARCH GRANULES

Guangjun Chen et al (2008) introduced the newnanocomposites of WPU reinforced with StNs.

PBA and TDI based PU matrix + Starch nanocrystals

OUTCOME OF THE STUDYElongation at break is increased 1406%Tensile strength is increased 28 to 51 MPaTg is also increased

The powdered starch basedpolyurethane is used for surgical glovesas non sticking powder.

The starch based polyurethane is usedfor culture growth of Penicilliumexpansum and Aspergillus oryzae.

Starch-polyurethane blend isalso used in formation of foams.

It is biodegradable and notharmful for terrestrial andaquatic life.

The films formed by starchbased polyurethane are usedin the food packaging becausethey are colorless, odorless,tasteless and non toxic.

It is used in agriculture forcontrolled release of fertilizerand its films are used to coverthe greenhouse.

It is also used in the medical field because is biocompatible, better mechanical properties and the products produced after their degradation are non toxic in nature.

This material provides information about theformation of biodegradable polymer from therenewable resources, improves their properties andthe modified polymers are recyclable, biodegradableand also have large number of applications such as inmedical field and fertilizer industry.

1. Barikani M., Mohammadi M. (2007). Synthesis and characterization of starch modified polyurethane, Carbohydrate Polymer.68:773-780.

2. Kugler S. (2010). Trend in development of biodegradable starch and polyurethane materials, Science techniques.64:7-8,531-538.

3. Santayanon R., Wootthikanokkan J. (2003). Modification of cassava starch by using propionic anhydride and properties of the starch-blended polyester polyurethane, Carbohydrate Polymer.51:17-24.

4. Lu Y., Tighzert L., Dole P., Erre D. (2005). Preparation and properties of starch thermoplastics modified by waterborne polyurethane from renewable resources, Polymer.46:9863-9870.

5. Ha S.K., Broecker H.C. (2002).Characteristics of polyurethane incorporating starch granules, Polymer.43:5227-5234.

6. Da Roz A L., Curelo A.A.S., Gandini A.(2009). Preparation and characterization of cross-linked starch polyurethane, Carbohydrate Polymer.77:526-529.

7. Chen G., Wei M., Chen J., Dufresne., Chang P R.(2008). Simultaneous reinforcing and toughening: New nanocomposites of waterborne polyurethane filled with low loading level of starch nanocrystals, Polymer.49:1860-1870.

8. Cao X., Chang P R., Huneault M. A.(2008).preparation and properties of plastizedstarch modified with poly(ε-caprolactone) based waterborne polyurethane, CarbohydratenPolymer.91:119-125.

9. Lu Y., Tighzert L.,Berzin F., Rondot S.(2005). Innovative plasticized starch film modifed with waterborne polyurethane from renewable resources, Carbohydrate Polymer.61:174-182.

10. Wang Y., Tian H., Zhang L.(2010). Role of starch nanocrystals and cellulose whiskers in synergistic reinforcement of waterborne polyurethane, Carbhohydrate Polymer.80:665-671.

11. Zia K M., Barikani M., Bhatti I J., Zuber M.(2008). Synthetic and thermomechanical characterization of polyurethanen elastomer extended with α,ω- Alkane diol, Applied Polymer Science.109:1840-1849.

12. Wang Y., Lue A., Zhang L.(2008). Rheological behaviour of waterborne polyurethane/starch aqeous dispersion during cure, Polymer.50:5474-5481.

13. Spychaj T., Wilpiszewska., Spychaj S.(2007). Starch-urethane polymer phesicochemical aspects,properties, appliccation, Engineering biopolymer: Homopolymer blend and composites:155-165.

14. Alfani R., Iannace S., Nicolais L.(1998) Synthesis and characterization of starch-based polyurethane fomes, Applied polymer Science.68:739-745.

References

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