Special Types of Polyurethane Elastomers

In addition to the well-established classes of polyurethane elastomers, a variety of chemically modified varieties have been marketed commercially designed for specific applications. An account of some of these is now given. 

---

Polyurethane rubbers are a special type of PU elastomer. The PU rubbers are highly resistant to oil and fuel and have high abrasion resistance and tensile strength similar to PU elastomers. Polyurethane rubbers maintain their flexibility even at a temperature as low as -40° C and are thermally stable up to 125°C. Polyurethane rubbers have better mechanical strength and resist abrasion, ozone, and oil better than other specialty rubbers such as acrylates and nitrile butadiene. ... 

Among the polyurethane, polyester, and polyamide thermoplastic elastomers, those with polyether-based elastomer segments have better hydrolytic stabihty and low temperature flexibiUty, whereas polyester-based analogues are tougher and have the best oil resistance (43). Polycaprolactones and aUphatic polycarbonates, two special types of polyesters, are used to produce premium-grade polyurethanes (12). 

A curable epoxy resin containing a crosslinked elastomeric latex " yields a special type of sequential IPN. The elastomers mentioned include SBR, EPR, NBR, silicone rubber, and PEA. Hawkins " described an epoxy/polyurethane semi-SIN, and Mendoyanis " revealed an epoxy/liquid rubber SIN. The liquid rubbers were based on polysulfide rubber or polyethylene. The final products could be extended to 400% at... 

Castable Polyurethane Elastomers explains the production process of polyurethane components from both the theoretical and practical points of view. It describes the underlying concepts for the raw material supplier recommendations and explains how to achieve application-specific properties in polyurethane. The book explains the production of prepolymers with special focus on health and safety issues. It presents the different types of methods available on both the micro and macro levels and explains the rationale behind choosing the system needed to create a cost-effective, application-specific product. 

Rubbers and elastomeric products for practical applications are usually blends of different elastomer types that develop specific domain morphologies at the microscale, and, therefore, they are a part of this chapter. The most common representatives of the ruhher family are natural ruhher (NR) and the synthetic polyhutadiene ruhher (PB). There are various copolymers of butadiene with styrene (styrene butadiene rubber, SBR) or acrylonitrile (acrylonitrile-butadiene rubber, NBR). Several elastomers have been developed for special purposes, such as EVA (ethylene vinyl acetate copolymer), PU (polyurethane), EPDM (ethylene propylene terpolymer), and siUcone rubber. 

---