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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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14
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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