Synthesis of Thermoplastic Polyurethane

A typical method for the preparation of a thermoplastic polyurethane (TPU) elastomer involves the following procedure the desired polyol/ 

EFFECT OF POST-CURE ON THE PHYSICAL PROPERTIES OF PARTIALLY CROSSLINKABLE THERMOPLASTIC POLYURETHANES  

Polycaprolactone, mol. wt 2000 (Capa 220 by Interox Chemicals, Warrington, Cheshire, 

Reaction stoichiometry is calculated based on the complete reaction of all diisocyanate groups with hydroxyl groups present to give a fully OH end-blocked TPU. 

Its molecular weight is 2000 and its functionality is evidently 2 hence the equivalent weight is 2000/2= 1000. Similarly, MDI of formula 

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The application of chaotic flows leads to much smaller droplets than allowed by the equilibrium between the shear and interfacial forces [204-206] and than those obtained in some commercial mixers. The smaller size of droplets can be directly traced back to their precursor thinner flbrils as the droplets originate from the fibrils by capillary instability and breakup. The exponential stretching encountered in chaotic mixers subdues the growth of interfacial instabilities in both lamellas and fibrils and consequently smaller diameter fibrils are produced. In some cases, fibrils with an aspect ratio as high as 1000 are produced [204]. In addition, the chaotic mixing conditions have been shown to slow down the rate of coalescence of droplets [207]. Another study utilized the rapid intermaterial area generation in chaotic flows to promote chemical reactions in the synthesis of thermoplastic polyurethanes [140]. 

Pattanayak, A. and Jana, S.C. (2005) Synthesis of thermoplastic polyurethane nanocomposites of reactive nanoclay by bulk polymerization methods. Polymer, 46, 3275. 

Jung, C. (2005) Synthesis of thermoplastic polyurethanes and polyurethane nanocomposites imder chaotic mixing conditions. Ph.D. Thesis, University of Akron, Akron, OH. 

More AS, Lebarbe T, Maisonneuve L, Gadenne B, Alfos C, Cramail H. Novel fatty acid based di-isocyanates towards the synthesis of thermoplastic polyurethanes. Eur Polym J 2013 49(4) 823-33. 

More, A., Lebarbe, T., Maisonneuve, L., Gadenne, B., Alfos, C., and Cramail, H. (2013) Novel fatty adds based di-isocyanates towards the synthesis of thermoplastic polyurethanes. European Polymer Journal, 49 823-833. 

Hsu T-F and Lee Y-D (1999) Properties of thermoplastic polyurethane elastomers containing liquid crystalline chain extender (I) Synthesis and properties of hard segments, FnZj/mer 40 577-587. 

The vitality of this field is further demonstrated by a continuous search for original ways of exploiting vegetable oils. Examples include self-healing elastomers in which fatty acids play a central role [46] the esterification of cellulose with fatty acids to give thermoplastic materials [47] the synthesis of a saturated aliphatic diisocyanate from oleic acid and its subsequent use in the preparation of fully biobased polyurethanes in conjunction with canola oil-derived polyols [48] and novel elastomers from the concurrent cationic and ring-opening metathesis polymerization of a modified linseed oil [49]. 

Aran-Ais E, Torro-Pala A.M., Orgiles-Barcelo A.C., Martin-Martinez J.M., Addition of rosin acid during thermoplastic polyurethane synthesis to improve its immediate adhesion to PVC, Int. J. Adhes. Adhes., 25(1), 2005, 31-38. 

Moore T. Design and synthesis of biodegradable thermoplastic polyurethanes for tissue engineering. (Australia) Swinbitme University of Technology 2005. [Ph.D. thesis]. 

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