Rubber blends properties

Improvement in the solvent and oil resistance of rubbers can be achieved via grafting of acrylonitrile onto rubber [140-142] and rubber blends [143]. The careful control of the degree of grafting allows vulcanized rubber with high-mechanical properties compared with ungrafted vulcanized rubber to be obtained. Also, acid resistance [144] and resistance to microbiological attack [145,146] was improved for cellulose grafted with acrylonitrile, and increases in base resistance were also noted for MMA and a mixture of MMA and ethyl acrylate [13],... 

The reactive extrusion of polypropylene-natural rubber blends in the presence of a peroxide (1,3-bis(/-butyl per-oxy benzene) and a coagent (trimethylol propane triacrylate) was reported by Yoon et al. [64]. The effect of the concentration of the peroxide and the coagent was evaiuated in terms of thermal, morphological, melt, and mechanical properties. The low shear viscosity of the blends increased with the increase in peroxide content initially, and beyond 0.02 phr the viscosity decreased with peroxide content (Fig. 9). The melt viscosity increased with coagent concentration at a fixed peroxide content. The morphology of the samples indicated a decrease in domain size of the dispersed NR phase with a lower content of the peroxide, while at a higher content the domain size increases. The reduction in domain size... 

Handbook of elastomers , A.K. Bhowmick and H.L. Stephens Marcel Dekker (1988) Series Plastics Engineering, Volume 19 ISBN 0824778006. This handbook systematically addresses the manufacturing techniques, properties, processing, and applications of rubbers and rubber-like materials. The Handbook of Elastomers provides authoritative information on natural rubbers, synthetic rubbers, liquid rubbers, powdered rubbers, rubber blends, thermoplastic elastomers, and rubber-based composites— offering solutions to many practical problems encountered with rubber materials. 

Typical Properties of Thermoplastic Elastomers Developed from Nylon-6-Acrylate Rubber Blends... 

Unlike a plastic blend where the properties largely depend on the properties of the individual component and the compatibUizer used, those of a rubber blend depend on the solubility and diffusivity of the curatives, reaction rates, scorch time, etc. Figure 11.16 gives relative cure rate and scorch time for a number of accelerators. Hence, in designing a rubber blend, aU these parameters have to be taken into consideration in order to obtain good properties along with good processability. 

Hong, B. K. and Jo, W. H. (2000) Effects of molecular weight of SEBS triblock copolymer on the morphology, impact strength, and rheological property of syndiotactic polystyrene/ ethylene-propylene rubber blends. Polymer, 41, 2069-2079. 

One of the first applications envisioned of ROMP was the preparation of polyenes with rubber-like properties by ROMP of cyclopentene. Although this polymer did not have the optimum product profile, the polymer obtained by ROMP of cyclooctene can indeed be used in blends with other rubbers, conferring on the final product improved mechanical properties and simplifying its processing. This polymer, called Vestenamer 8012, is being produced by Chemische Werke Hiils, Marl, Germany, and the annual capacity in 1990 reached 12000t. 

As regards high Irons- 1,4-poly butadiene, it has a few applications, especially as a blend with natural rubber. Syndiotactic 1,2-polybutadiene is a unique material that combines the properties of plastic and rubber. These properties lead to applications both as a thermoplastic resin and as a rubber. As regards isotactic 1,2-polybutadiene, one may note that its properties have not excited sufficient interest for commercial development. 

Kole S, Roy S, Bhowmick AK (1995) Influence of chemical interaction on the properties of silicone-EPDM rubber blend. Polymer 36(17) 3273-3277... 

Blends with Nitrile Rubbers. The data in Table III show the importance of using a terpolymer rubber to obtain good impact strength in a blend with styrene-acrylonitrile-DBPF terpolymer resin. Blend No. 1 gives the properties of a conventional nitrile rubber blend type ABS. Blends 2-4, involving terpolymer resins with the same amount of the rubber used in Blend 1, have a much lower impact strength. 

Table V. Effect of Tricresyl Phosphate on the Properties of a Nitrile Rubber Blend DBPF-Containing ABS...

Nitrile rubber finds broad application in industry because of its excellent resistance to oil and chemicals, its good flexibility at low temperatures, high abrasion and heat resistance (up to 120°C), and good mechanical properties. Nitrile rubber consists of butadiene—acrylonitrile copolymers with an acrylonitrile content ranging from 15 to 45% (see Elastomers, synthetic, nitrile rubber). In addition to the traditional applications of nitrile rubber for hoses, gaskets, seals, and oil well equipment, new applications have emerged with the development of nitrile rubber blends with poly(vinyl cliloride) (PVC). These blends combine the chemical resistance and low temperature flexibility characteristics of nitrile lubber with the stability and ozone resistance of PVC. This has greatly expanded the use of nitrile rubber in outdoor applications for hoses, belts, and cable jackets, where ozone resistance is necessary. 

Ismail, H. Suzaimah, S. Hairunezam, H.M. Curing characteristics, mechanical properties and oil resistance of styrene butadiene rubber/epoxidized natural rubber blends. J. Elastomers Plast. 2002, 34 (2), 119-130. 

Sanchez-Solis, A. Estrada, M.R. Cruz, J. Manero, O. On the properties and processing of polyethylene terephthalate/styrene-butadiene rubber blend. Polym. Eng. Sci. 2000,40 (5), 1216-1225. Luzinov, I. Xi, K. Pagnoulle, C. Huynh-Ba, G. Jerome, R. Composition effect on the core-shell morphology and mechanical properties of ternary polystyrene/styrene butadiene rubber polyethylene blends. Polymer 1999, 40 (10), 2511-2520. 

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