Lengths, elastomer properties

M. M. Sonpatki, K. Ravindranath, S. Ponrathnam, Random thermotropic elastomers. I Effects of substitution and hard/soft segment lengths on properties J. Polym. Sci. Part A Polym. Chem., 32, 2999-3007 (1994). 

A.K. St. Clair, T.L. St. Clair, and S.A. Ezzell, "The Effect of Elastomer Chain Length on Properties of Silicone-Modified Polyimide Adhesives," NASA TM-83172 (1981). 

Plastic elastomers are generally lower-modulus flexible materials that can be stretched repeatedly and will return to their approximate original length when the stresses are released. The rubber materials have been around for over a century. They will always be required to meet certain desired properties, but thermoplastic TPEs are replacing traditional TS natural and synthetic rubbers (elastomers). TPEs are also... 

The mechanical properties of X depend partly on the length of the oli-goethyleneoxy groups. The polymers are solid for x=l, highly viscous gums for x=3 and elastomers for x=7.2. The maximum conductivity of these complexes at 30 °C are reported in Table 16. Gel electrolytes have also been obtained by adding propylene carbonate (PC) (10-50 wt%) to these polynorbornene de-... 

The properties of PHAs are dependent on their monomer composition and therefore it is of great interest that recent research has revealed that, in addition to PHB, a large variety of PHAs can be synthesized microbially. The monomer composition of PHAs depends on the nature of the carbon source and microorganism used. PHB is a typical highly crystalline thermoplastic whereas medium chain length PHAs are elastomers with low melting points and a relatively lower degree of crystallinity. By (chemical) modification of the PHAs, the ultimate properties of the materials can be adjusted even further, when necessary. 

Block copolymers possess unique and novel properties for industrial applications. During the past 20 years, they have sparked much interest, and several of them have been commercialized and are available on the market. The most common uses of block copolymers are as thermoplastic elastomers, toughened thermoplastic resins, membranes, polymer blends, and surfactants. From a chemist s point of view, the most important advantage of block copolymers is the wide variability of their chemical structure. By choice of the repeating unit and the length and structure of both polymer blocks, a whole range of properties can be adjusted. 

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