Elastomers containment

L. D. Albia and M. M. Lynn, Chemistry of Elastomers Containing Vinylidene Fluoride, at the MCA Meeting of the Energy Rubber Group, Rubber Division, Educational Symposium, Arlington, Tex, Sept. 23, 1985, American Chemical Society, Washiagton, D.C. 

Aromatic Amines. Antioxidants derived from -phenylenediarnine and diphenylamine are highly effective peroxy radical scavengers. They are more effective than phenoHc antioxidants for the stabilization of easily oxidized organic materials, such as unsaturated elastomers. Because of their intense staining effect, derivatives of -phenylenediamine are used primarily for elastomers containing carbon black (qv). 

Although these curative systems may also be used with the polyepichlorohydrin elastomers containing AGE, the polymers were developed to be cured with conventional mbber curatives, sulfur, and peroxides. These polymers containing the pendent aHyl group are readily cured with a typical sulfur cure system such as zinc oxide, and sulfur along with the activators, tetramethylthiuram mono sulfide [97-74-5] (TMTM) and... 

Figure 2.2 Stress-strain curve of polyester elastomer containing 58 wt% PBT. A, slope = Young s modulus B, yield stress. (Reprinted with permission from ref. 190, p. 96. Copyright 1988 John Wiley Sons, Inc.)...

Anionic polymerization of pivalolactone with the polystyrene anion produced only homopolymer mixtures, but the polystyrene carboxylate anion was able to give a block copolymer336. The block efficiency depends on catalyst ratio and conversion because the initiation step is slow compared with propagation337. Tough and elastic films were obtained by graft copolymerization or block copolymerization of pivalolactone onto elastomers containing tetrabutylammonium carboxylate groups338,339. ... 

Skaija GA and Woodhouse KA. S3mthesis and characteization of degradable pol)oirethane elastomers containing an amino acid based chain extender. J Biomater Sci Polym Ed, 1998, 9, 271-295. 

PU elastomers contain alternative soft and hard segments, which separate into different phases. Hard domains play a role of cross-links, whereas soft blocks provide extensibility. Therefore, morphology and properties of PU are defined by relative amount of soft and hard segments. For example, at 70% concentration of soft segments, the material is described as a mbbery matrix with... 

Kumar, R.C., Fuhrmann, I., and Kocsis, J.K., LDPE-based thermoplastic elastomers containing ground tire rubber with and without dynamic curing, Polym. Degrad. Stab., 76, 137, 2002. 

Ionomer-type elastomers, containing small amounts (less than 5%) of metal carboxylate or sulfonate groups, have potential as a new class of thermoplastic elastomers. Carboxylic acid groups are introduced into polymers such as polybutadiene by copolymerization with a monomer such as acrylic or methacrylic acid. 

This estimated value of is twofold or more larger than the computed values of Gj ax in Table m. This difference could result if the sol fractions (Table I) are actually less than the true values, for reasons mentioned earlier, and if h is greater than zero. For PDMS elastomers containing trifunctional junctions, h has been reported (19) to be 0.95. 

Elastomers containing fluorine, also called fluorelastomers. These combine the good physical properties of organic elastomers with the thermal stability of inorganic materials. Trade names are Viton, Fluorel, Kel-F and Technoflon. 

The reaction of polyethylene with chlorine in the presence of sulfur dioxide yields an elastomer containing both chloro and chlorosulfonyl groups... 

Figure 13. Critical stress (a) vs. Young s modulus of elastomers containing spherical inclusions. k= 0.74 minr1 T = 25°C.

Known as MR. butyl rubber is a copolymer of isobutylene and isoprene. The elastomers contain only (1.5 2.5 mole 9r of isoprene. This is introduced to effect sufficient unsaturatinn to make the rubber vulcanizublc. Polymerizations are usually earned out at low temperature (-80 to -1(KJ C) with methyl chloride as solvent. Anhydrous aluminum chloride and a trace of water serve as catalyst. 

Acrylic elastomer, containing only 0.1 phr Wingstay V and 0.1 phr of DLTDP 1000... 

The carboxyl terminated polybutadiene (C-3000) is about equally effective to CTBN in heat distortion temperature and impact but considerably less effective in strength. From the haze data (the percent haze of ERL-4221 modified with 10 phr of CTBN and C-3000 were 17 and 85% respectively) it is quite clear that this elastomer (C-3000) is highly incompatible with the epoxy-hardener system in the cured state. A 2000 molecular weight polybutadiene elastomer, containing no carboxyl groups, was completely incompatible with the epoxy system and segregated in the cured state. 

Fluorouracil was relatively stable in PVC containers compared with glass, but this depends on concentration and storage temperature. Fluorouracil solutions are incompatible with synthetic elastomers containing packaging and infusion materials.218,219... 

Gornowicz G et al. (2003) Thermoplastic elastomers containing polyurethanes and silicone. WO Patent 2003035757... 

Title Synthesis of Energetic Thermoplastic Elastomers Containing Both Polyoxirane and Polyoxetane Blocks... 

In order to fully develop physical properties such as tensile strength, elongation, and compression set, perfluoro elastomers must be cured. Perfluoro elastomers containing vinyl acetate units were prepared that, when saponified with sodium hydroxide, provide hydroxyl cure sites. 

The thermal stability of fluorocarbon elastomers also depends on their molecular structure. Fully fluorinated copolymers, such as copolymer of TFE and PMVE (Kal-rez), are thermally stable up to temperatures exceeding 300°C (572°E). Moreover, with heat aging this perfluoroelastomer becomes more elastic rather than embrittled. Eluorocarbon elastomers containing hydrogen in their structures (e.g., Viton, Dyneon, and DAI-EL EKM) exhibit a considerably lower thermal stability than the perfluori-nated elastomer. Eor example, the long-term maximum service temperature for FKM... 

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