Thermoplastic elastomers, synthesis polyurethanes

Marija Pergal, MSc, works at the Department for Polymeric Materials, Institute for Chemistry, Technology and Metallurgy since 2003 as Research Scientist. Since 2007 she is also Teaching Assistant for the course Chemistry of Macromolecules at Department of Chemistry, University of Belgrade. Her research interests are focused on synthesis and characterization of siloxane homopolymers and copolymers, especially thermoplastic elastomers based on poly(butylene terephthalate) and polyurethanes, as well as polyurethane networks based on hyperbranched polyester. In addition to physico-chemical, mechanical and surface properties of polymers, her particular interest is directed towards the study of biocompatibility of polymer materials. 

Synthesis and properties of polyurethane thermoplastic elastomers comprising hydrazine derivatives... 

It should be mentioned that the Contributors, the Editor, as well as the Publisher are well aware that, strictly speaking, the title Condensation Thermoplastic Elastomers is chemically not sufficiently correct for the covered classes of polymers. Nevertheless, it was preferred, e.g., to the chemically correct title Thermoplastic Elastomers by Poly condensation and Polyaddition , at least for the following reasons (i) the polyurethane group behaves chemically much more as a typical polyester or polyamide group, rather than as a polyolefin, (ii) similarly to other cases e.g., the synthesis of nylon 6) regardless of the chemical route of the synthesis, via polymerization or via polycondensation, the final polymer is distinguished by a chemical structure typical of polycondensates, and (iii) the selected title sounds more comprehensive and more attractive. 

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]. 

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

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. 

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. 

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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