An interpenetrating polymer network (IPN) based on poly(ethyl methacrylate) (PEMA) and carboxylated nitrile rubber was synthesized. Peroxide crosslinked XNBR was swollen in ethyl methacrylate containing benzoyl peroxide as initiator and tetraethylene glycol dimethacrylate as crosslinking agent. A full and sequential IPN is formed by the two independently crosslinked phases of XNBR and PEMA. Dynamic mechanical analysis of the 50/50 XNBR/ PEMA IPN shows a single, broad peak whereas a 50/50 blend shows two distinct peaks, indicating the pinning down of a microheterogeneous structure during the IPN formation rather that macrophase separation as in blends. SEM analysis confirms the development of a cocontinuous intimate structure of the IPN.

An investigation on the effect of filler geometry/shape on the dynamic mechanical properties of polymers was conducted. The viscoelastic damping matrix chosen was SBR and the fillers chosen were graphite, aramid, and carbon short fibers. The study was conducted by taking a control base compound of 20 parts N330 carbon black-filled styrene butadiene rubber (SBR). Dynamic mechanical thermal analyzer was used to investigate the viscoelastic damping of the rubber composites at low dynamic strain levels. Compressive hysterisis at moderate degree of strain were evaluated for all the composite samples to probe into their high strain static damping properties. SEM was used to investigate the matrix-fiber interaction and distribution of the fillers. Investigations demonstrated that the matrix-filler interface plays a major role in energy dissipation. The amount of interface was analyzed by considering the half height width of tan d peak. Fiber matrix interaction parameter was calculated from the tan d max values for matrix and composite. It was observed the interaction parameter and the low strain tensile stress values register similar trend. Aramid short fibers were most effective in more energy dissipation than other fillers under consideration.

Polyaniline doped with (Ϯ)-camphor sulfonic acid was blended with polyvinyl chloride/nitrile rubber. The thermoplastic blend was characterized for its conductivity, mechanical and dynamic mechanical properties, and microwave response. The blend was found to be compatible in nature. Loss component of relative permittivity increased with polyaniline content. Storage modulus increased with polyaniline content, whereas tan ␦ showed decline.

Ternary blends of thermoplastic polyurethane and a poly(vinyl chloride)/nitrile rubber blend were investigated in this work. The blends, with weight ratios of 100/0, 80/20, 40/60, 60/40, 80/20, and 0/100, were prepared via melt blending. Dynamic mechanical analysis showed that the blends with ratios of 20/80 and 80/20 were miscible, whereas the 40/60 and 60/40 blends were partially miscible. IR spectroscopy studies showed shifts in the peaks due to specific interactions in the blends. The blends showed degradation behavior between the blend components. The fracture toughness was investigated with the J-integral by the locus method; the components and the miscible blends had good fracture toughness, whereas the other blends had lower toughness. Similar behavior was observed for the tensile properties. Scanning electron microscopy studies showed the morphological variations in the blends.

A novel route for the preparation of rubber–carbon black–nanoclay (NC) nanocomposites with XNBR as a matrix and a carboxyl‐terminated copolymer of butadiene and acrylonitrile (CTBN) as a low‐molecular‐weight modifier for commercially available NC is presented in this article. The addition of NC to the rubber (after the NC was mixed with CTBN in a 2 : 1 ratio) showed remarkable improvement in the mechanical properties. The clay loading was varied from 0 to 10 parts per hundred rubber (phr). An amount of 20 phr N330 black was incorporated into all of the formulations. The properties were compared with those of a control XNBR compound having only 20 phr N330. X‐ray diffraction revealed a combination of a high level of intercalated and exfoliated structures in such nanocomposites. Transmission electron microscopy confirmed the improvement in dispersion as a result of addition of CTBN. A 127% increase in the tensile strength and a 53% increase in the elongation at break were achieved. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013