Elastomer definition

Classification Polymer synthetic elastomer Definition Unsaturated polymer of chloroprene Empirical (C4H5CI),... 

Classification Epichlorohydrin elastomer Definition Vulcanized with sulfur or peroxides vulcanizates have good heat/weather/flame/oil resist, exc. low temp, props. 

Classification Polymer synthetic elastomer Definition Unsaturated polymer of chloroprene Empirical (C4HsCI)x Formula [CH2CH=CCICH2]x Properties As solid, latex, or flexible foam m.w. 100,000-300,000 dens. 1.23-1.35 brittle pt. -35 C softens. 80 C ref. index 1.5512 (20 C) high tens, str. resilient resistant to oils, oxygen, ozone, elec, current, abrasion... 

Polyfll 40, Polyfll 70. See Aluminum silicate Polyfll 100. See Aluminum hydroxide Polyfll DL, Polyfll F, Polyfll FB, Polyfll HG, Polyfll HG-90, Polyfll X, Polyfll XB. See Aluminum silicate Polyfin. See Polyethylene wax Polyflex 300 Retention Aid. See Polyacrylamide Polyfluoroalkoxyphosphazene Synonyms PNF Poly (fluoroalkoxyphosphazene) elastomer Definition Elastomer with exc. low-temp, flexibility, good resist, to weather/soivs./acid, good mech. props, at -75 to 150 C... 

Classification Thermoplastic elastomer Definition Polymer of isoprene major component of natural rubber, also made synthetically avail, in range of std., oil-extended and carbon bik.-filled grades props, vary with catalysts used in mfg. (lithium, titanium)... 

Classification Thermoplastic elastomer Definition Polymer consistg. of hard segments embedded in a soft, elastomeric polyol phase exc. abrasion/impact resist. high str. wide working temp, range good hydrolytic stability two types polyether- or polyester-based Properties Solid... 

Classification Elastomer Definition Rubber deriv. mfg. by passing chlorine into sol n. of rubber in chloroform, CCI4, etc. characterized by good film-forming and elec./thermal insulation props. good resist, to acids, alkalis... 

Classification Thermoplastic elastomer Definition Produced by coupling styrene-isoprene diblock copolymers into S-l-S triblock with typical styrene content of 14%... 

The rubber definition with its swelling test certainly limits it to only the natural latex tree sources, whereas the elastomer definition is more in line with modem new... 

Various materials (e.g., metal, plastics, or rubber) are used to make the flexing elements in these couplings. The use of the couplings is governed by the operational fatigue limits of these materials. Practically all metals have fatigue limits that are predictable, therefore, they permit definite boundaries of operation to be established. Elastomers such as plastic or rubber, however, usually do not have a well-defined fatigue limit. Their service life is determined primarily by conditions of installation and operation. 

For satisfactory operation, the rubber lining must be adequately bonded to the substrate it is protecting. BS 6374 part 5 gives definitive load to peel levels for various elastomers, but it is usually required that, on separation, the rubber should tear rather than part either at the primer/rubber interface or the primer/substrate interface. 

Microcellular elastomers16 bridge the gap between solid elastomers and low-density foams. Although they may appear to be noncellular, these materials have a microscopic cell structure and so are by definition high-density foams, with densities between noncellular solids and standard foams. The most commercially important applications include shoe soles, carpet backing, chair armrests,... 

At present the situation in the field of inorganic polymeric materials is dominated by polysiloxanes (silicones) [14, 24-27], whose utilization as low temperature elastomers, thermally stable fluids, biomaterials etc., is definitely well established. 

More definitive evidence of enzymatic attack was obtained with 1 1 copolymers of e-caprolactone and 6-valerolactone crosslinked with varying amounts of a dilactone (98,99). The use of a 1 1 mixture of comonomers suppressed crystallization and, together with the crosslinks, resulted in a low-modulus elastomer. Under in vitro conditions, random hydrolytic chain cleavage, measured by the change in tensile properties, occurred throughout the bulk of the samples at a rate comparable to that experienced by the other polyesters no weight loss was observed. However, when these elastomers were implanted in rabbits, the bulk hydrolytic process was accompanied by very rapid surface erosion. Weight loss was continuous, confined to the... 

The value of Q is obtained from the plot of /2(X - X-2) versus and extrapolating to = 0. By comparison with the theory of elasticity, it has been proposed that Q = V2 NRT, where N is cross-link density, R the gas constant and T absolute temperature (of the measurement). When carbon black or other fillers are added to the elastomer, the prediction of the cross-link density is less definitive. 

Rubber - An elastomer, generally implying natural rubber, but used loosely to mean any elastomer, vulcanized and unvulcanized. By definition, a material that is capable of recovering from large deformations quickly and forcibly. 

RESINS (Synthetic). A manufactured high polymer resulting from a chemical reaction between two (or more) substances, usually with heat or a catalyst. This definition includes synthetic rubbers and silicones (elastomers), but excludes modified, water soluble polymers (often called resins). Distinction should be made between a synthetic resin and a plastic the formei is the polymer itself, whereas the latter is the polymer plus such additives as niters, colorant, plasticizers etc. See also Elastomers and Plasticizers. 

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