Thermoplastic polyurethane synthesis

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. 

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. 

Fig. 2.4. Synthesis principle for simple thermoplastic polyurethane elastomers.

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. 

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

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. 

The general reaction chemistry used in the synthesis of common rubbers and elastomers mentioned in Table 21.1 is described in the following. The discussion covers four types of rubbers styrene-butadiene rubbers (SBRs), polybutadiene, ethylene-propylene-diene rubbers, and thermoplastic polyurethanes. 

Rogulska, M., Podkoscielny, W., Kultys, A., Pikus, S., Pozdzik, E. (2006), Studies on thermoplastic polyurethanes based on new diphenylethane-derivative diols. Part 1 Synthesis and characterization of nonsegmented polyurethanes from HDl and MDl, Eur. Polym. J., 42,1786-97. 

Sonnenschein M F, Rondan N, Wendt B and Cox J M (2004) Synthesis of transparent thermoplastic polyurethane elastomers, J Polym Sci Part A Polym Chem 42 271-278. Sonnenschein M F, Lysenko Z, Brune D A, Wendt B L and Schrock A K (2005) Enhancing polyurethane properties via soft segment crystallization. Polymer 46 10158-10166. 

PUs can be both thermoplastic and thermosetting materials composed by HS and SS. Thermoplastic polyurethanes (TPU) are formed by linear polymer chains with functionality equal to two. This means that the SS, the polyol, is a diol and the HS, the isocyanate, is a diisocyanate. The thermodynamic incompatibility between the hard and the SSs as well as the NCO OH ratio, the synthesis procedure, etc. can generate a phase separation into the TPU. On the other hand, the thermosetting PUs are formed by polyols and/or isocyanates with functionalities higher than 2, with a NCO OH ratio higher than 1 or are obtained by using cross-linker agents. 

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. 

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