Physico-mechanical properties elastomers

Table 1. Dependence of the kinetic parameters of the reaction, the structural parameters of the network and the physico-mechanical properties of polyurethane elastomers on the molar fraction of OH groups in the monofunctional reagent21...

The PU elastomers obtained from polyether diols with DMC catalysts (Acclaim Polyols of Bayer) have a spectacular improvement in the majority of physico-mechanical properties when compared with PU elastomers made from the polyether diols, obtained by anionic catalysis. 

Chapter 12.5). Polyester polyols in reality, have the theoretical functionality, which is a great advantage for many polyurethane applications. For polyester diols the functionality is 2 OH groups/mol. This structural aspect results in the polyester diols giving PU elastomers with excellent physico-mechanical properties, superior to all polypropylene glycols obtained by anionic PO polymerisation. 

The hydroxyl terminated polybutadienes lead to PU with physico-mechanical properties significantly lower than those of PU based on polyether or polyester polyols. The nonpolar polymeric chain and the extraordinary hydrophobicity mean that hydroxy terminated polybutadienes are used for special applications, due to their excellent electrical insulation properties which are equal or superior to epoxies or silicone elastomer systems. The hydrolytic stability of PU elastomers derived from hydroxyl terminated polybutadiene is superior to the majority of other types of PU. Thus, some specific applications of... 

This relative order explains that numerous physico-mechanical properties of the polyurethanes based on polyester polyols are superior to the polyurethanes derived from polyether polyols or from polyhydrocarbon polyols (this relative order is valuable for PU elastomers, flexible and rigid PU foams). 

Odler, L, and Liang, L. (1992) Physico-mechanical properties of cementitious systems modified by elastomer dispersions, in Proceedings 7th International Congress on Polymers in Concrete, Moscow, pp. 201-212. 

In the case of elastomers according to E.M Dannenberg, the reinforcement represent the phenomenon of the increase of rigidity, modulus, fracture energy, resistance to fatigue, cracking, and abrasion [1193]. From the practical point of view, it is defined as the process that determines the increase of the exploitation period of polymers, due to the increase of their physico-mechanical properties. 

Sahoo BP, Naskar K, Tripathy DK (2012) Conductive carbon black-filled ethylene acrylic elastomer vulcanizates physico-mechanical, thermal, and electrical properties. J Mater Sci 47 2421... 

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. 

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