Thermoplastic elastomers high-performance

OBCs are advantaged in their eapability to retain oil when compared to Polyolefin Elastomers of similar density and Ml, and can therefore deliver lower hardness compounds ( 20 Shore A). This is hypothesized to be due to the OBC block structure wherein the blocks of amorphous segments may allow for more swelling and oil incorporation. Oil-filled OBCs also show decreased compression set at both room temperature and elevated temperature, which is again attributed to their imique block structure. These combined benefits expand Ae application range of OBC compounds to include markets currently served by high performance thermoplastic elastomers, such as styrenics block copolymers (SBCs), thermoplastic urethanes (TPUs) and thermoplastic vulcanizates (TPVs). 

Even when phase separation of a rubber such as CTBN or a HBP is optimized to produce an effective material, there will be the small fraction of the disperse phase that is soluble in the continuous phase, and trapped there at gelation. As noted earlier, this can affect the Tg if an elastomer is used, but is not a problem with the high-performance thermoplastics such as PES. 

Sonnenschein, M. R, Ginzburg, V. V., Schiller, K. S., Wendt, B. L. (2013). Designing, polymerization, and properties of high performance thermoplastic polyurethane elastomers from seed-oil derived soft segments, Po/h 1 j 18,1350-1360. 

While a process of iterative redesign is often the only way to proceed when considering the use of high performance polyester elastomers, completely new thermoplastic elastomers are being invented with a range of properties and cost savings which permit them to be substituted directly for conventional thermoset rubber. 

Seymour, R. B., Engineering Polymer Sourcebook , McGraw-Hill, New York, 1990. The design, processing, fabrication and application of many high performance thermosets and high performance, thermoplastics is presented, including elastomers, styrenic, acrylic, polycarbonate, acetal polyamides, isocyanate, poly(phenylene oxide), fluorocarbons, polyimides and polyethers. 

High Performance Thermoplastic Aramid Elastomers Synthesis, Properties, and Applications... 

Uses. Vinyhdene fluoride is used for the manufacture of PVDF and for copolymerization with many fluorinated monomers. One commercially significant use is the manufacture of high performance fluoroelastomers that include copolymers of VDF with hexafluoropropylene (HFP) (62) or chlorotrifluoroethylene (CTFE) (63) and terpolymers with HEP and tetrafluoroethylene (TEE) (64) (see Elastomers, synthetic-fluorocarbon elastomers). There is intense commercial interest in thermoplastic copolymers of VDE with HEP (65,66), CTEE (67), or TEE (68). Less common are copolymers with trifluoroethene (69), 3,3,3-trifluoro-2-trifluoromethylpropene (70), or hexafluoroacetone (71). Thermoplastic terpolymers of VDE, HEP, and TEE are also of interest as coatings and film. A thermoplastic elastomer that has an elastomeric VDE copolymer chain as backbone and a grafted PVDE side chain has been developed (72). 

Polyesters are one of the most versatile classes of polymers ever produced, covering a wide range of properties and applications. Polyesters are present in fibers, engineering thermoplastics, and high-performance polymers as well as in thermosetting resins and elastomers. Table 2.1 lists the chemical structure, abbreviations, and uses of some commercially important thermoplastic polyesters. 

As a result of its saturated polymer backbone, EPDM is more resistant to oxygen, ozone, UV and heat than the low-cost commodity polydiene rubbers, such as natural rubber (NR), polybutadiene rubber (BR) and styrene-butadiene rubber (SBR). Therefore, the main use of EPD(M) is in outdoor applications, such as automotive sealing systems, window seals and roof sheeting, and in under-the-hood applications, such as coolant hoses. The main drawback of EPDM is its poor resistance to swelling in apolar fluids such as oil, making it inferior to high-performance elastomers, such as fluoro, acrylate and silicone elastomers in that respect. Over the last decade thermoplastic vulcanisates, produced via dynamic vulcanisation of blends of polypropylene (PP) and EPDM, have been commercialised, combining thermoplastic processability with rubber elasticity [8, 9]. 

It would seem that such broadened use of flexible plastics and rubbers in exterior-body structural members will compel the conclusion that high performance materials are needed. They must not only be relatively light, flexible, serviceable at temperature extremes, and easily fabricated and finished, but they must be as strong and as tough as possible. The public will demand this. One type of flexible synthetic polymer which meets these requirements very well indeed is the thermoplastic urethane elastomers which have already proved themselves in flexible front ends, sight shields, and fascia in production model automobiles. 

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