Elastomer properties

Butadiene—Methacrylic Acid Ionomers. Carboxyl groups can readily be introduced into butadiene elastomers by copolymerization, and the effects of partial neutralization have been reported (63—66). The ionized polymers exhibit some degree of fluidity at elevated temperatures, but are not thermoplastic elastomers, and are very deficient in key elastomer properties such as compression set resistance. 

Crosslinking Structures and Elastomers Properties, Technical Bulletin, Miles, Inc., Akron, Ohio. 

Fig. 3. Elastomer properties as a function of monomer composition, butyl acrylate (BA), ethyl acrylate (FA), and methoxyethyl acrylate (MEA). (a), (—) glass-transition temperature (------------) swelling in ASTM No. 3 oil (b) (-) residual elongation at break, %, after heat aging.

BRYDSON, j. A., Thei moplastic Elastomers Properties and Applications, RAPRA Review Report 81 (Vol. 7, no. 9) 1995... 

RUBBER AND SYNTHETIC ELASTOMERS Table 18.6 Summary of elastomer properties... 

ABA triblock copolymers of the styrene-diene type are well known, and owe their unique properties to their heterophase morphology. This arises from the incompatibility between the polystyrene A blocks and the polydiene B blocks, leading to the formation of a dispersion of very small polystyrene domains within the polydiene matrix. This type of elastic network, held together by the polystyrene "junctions", results in thermoplastic elastomer properties. 

Report 81 Thermoplastic Elastomers - Properties and Applications, J.A. Brydson. 

TiCl4 concentration, and blocking time. The star blocks exhibit an excellent combination of thermoplastic elastomer properties. The products exhibited excellent strengths and elongations (up to 27 MPa and 500%), in spite of the presence of 10-15% contaminants. They are potential easily processiable TPEs. 

Chain extenders Diols and diamines are generally used as chain extenders in PU industry and choice of chain extender influences elastomer properties considerably. The standard diol chain extender used for the synthesis of PU elastomer is 1,4-butane diol (BDO). Compared with a diol, better physical properties usually result when a diamine is employed as an extender. This is probably due to the introduction of urea linkages which enter into strong hydrogen bonded interactions. A diamine is usually chosen as the chain extender when a relatively unsymmetrical diisocyanate is employed. Diamines also function as efficient catalysts in addition to chain extenders. 

The surface of PDMS is hydrophobic which results in poor wettability with aqueous solvents and promotes non-specific protein adsorption. It is also relatively inert to chemical modification [25]. The liquid silicon rubber chosen for fabrication of the reaction plate contained pyrogenic silicic acid as a filler. Aside from its effect on elastomer properties the silicic acid can be expected to provide additional silanol... 

There are regulatory and handling problems in using methylene bis(2-chloroaniline) as a chain extender (curative or cross-linker) for toluene diisocyanate (TDI)-terminated prepolymers, to produce urethane elastomers (1,2). There is, therefore, a strong interest in achieving similar elastomer properties with other curatives and methylene diphenyl diisocyanate (MDI)-terminated prepolymers(3,4). 

Carboxylate-containing elastomers and the effects of the free acid and metal carboxylate groups on elastomer properties have been studied... 

J.A. Brydson, Thermoplastic Elastomers Properties and Applications, Rapra Review Report No.81, Volume 7, No.9, Rapra Technology, Shrewsbury, UK,... 

Polystyrene (S) was grafted on the butyl backbone by converting the ally lie chloride sites to initiating carbonium ions (R AlR Cl ). The product has thermoplastic elastomer properties. Most recently Kennedy and coworkers have developed techniques for grafting... 

Elastomer Properties. Mechanical properties, wettability, and swelling characteristics of a typical elastomer are summarized In Table IV. 

While true miscibility may not be required for elastomer properties, adhesion between the immiscible phases is required. Immiscible polymer blends that fulfill this criteria provide a significant opportunity to change the rheological, tensile, and wear properties of elastomer blends compared to miscible blends. 

Adhesion promoters added to the mixture (so-called direct bonding systems such as resorcin-formaldehyde-silica), are advantageous because the dipping process is unnecessary. Disadvantages include the high resin consumption level and the potential elastomer property changes similar to the effects of mold release agents in the mixture [32]. 

TPE can thus be processed like thermoplastics, but show typical elastomer properties under moderate conditions, see Sect. Structure of plastics in Chap. Properties of Plastics in Structural Components. ... 

Chem. Descrip. Proprietaiy Uses Defoamer for latex, PVC, and elastomers Properties Liq. 100%> solids BExM-1 [Tomah]... 

Chem. Descrip. Diethylene glycol linear adipate diol Uses Polyol for PU coatings, adhesives, elastomers Properties Vise. 19,000 cps hyd. no. 34-38 Storage Hygroscopic store in tightly closed containers Fomrez 11-56 [Uniroyal]... 

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