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The objective of this article was preparation of curable silane‐grafted poly(ethylene‐1‐butene) nanocomposite. The poly(ethylene‐1‐butene) was a polyolefin elastomer with random high comonomer content. Two preparation methods were investigated. The method of preparing nanocomposites significantly affected the mechanical properties of the resulted nanocomposites. So that, with the same formulation and different preparation methods, silane grafting with the first was 94% (PVDS3), while with the second was 33% (PS3VD). It was shown that the tensile strength of the cured nanocomposite prepared with the method 1 (PVDS3) increased four times higher than the pure resin. The effects of different factors such as the amount of silane and also the amount of silicon carbide on the physical, mechanical, and thermal properties of the cured and uncured nanocomposites were investigated. The rate of curing was depended on the silicon carbide concentration and 5 phr (part per hundred resin), and nano‐SiC was a concentration where the tensile properties were optimum. Thermal stability and the impermeability of the cured samples improved in the presence of nano‐silicon carbide. J. VINYL ADDIT. TECHNOL., 26:244–252, 2020. © 2019 Society of Plastics Engineers

Novel results on using mixtures of two external electron donors “phenyltriethoxysilane (donor A)” and “cyclohexylmethyldimethoxysilane (donor C)” in the synthesis of polypropylene/poly (ethylene‐co‐propylene) in‐reactor blends were presented. Thermal gradient elution fractionation (TGEF) was carried out to separate crystallizable copolymer fractions from the blends. FTIR, DSC, DMTA, and SEM were used to analyze the microstructure of the blends and separated fractions. Although using donor A as pure decreased the catalyst activity and molecular weight, using “donor A” in combination with donor C had a synergistic effect on the molecular weight of polypropylene homopolymers and the blends. The glass transition temperature (Tg) of the blend rubbery phase was the lowest in the case of the blend based on pure donor A because of formation of higher sequences of polyethylene and the Tg increased with increasing donor C concentration. PP–PE copolymer concentration and impact strength were found to be higher in the case of the blend based on donor ratio of A/C: 75/25 than other blends.