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Blends of polypropylene (PP) and thermoplastic elastomers (TPE), namely SBS (styrene-butadienestyrene) and SEBS (styrene-ethylene/1-butene-styrene) block copolymers, were prepared to evaluate the effectiveness of the TPE type as an impact modifier for PP and influence of the concentration of elastomer on the polymer properties. Polypropylene homopolymer (PP-H) and ethylene-propylene random copolymer (PP-R) were evaluated as the PP matrix. Results showed that TPEs had a nucleating effect that caused the PP crystallization temperature to increase, with SBS being more effective than SEBS. Microstructure characterization tests showed that in most cases PP/ SEBS blends showed the smallest rubber droplets regardless of the matrix used. It was seen that SEBS is a more effective toughening agent for PP than SBS. At 0°C the Izod impact strength of the PP-H/SEBS 30% b/w blend was twofold higher than the SBS strength, with the PP-R/SEBS 30% b/w blend showing no break. A similar behavior on tensile properties and flexural modulus were observed in both PP/TPE blends. Yield stress and tensile strength decreased and elongation at break increased by expanding the dispersed elastomeric phase in the PP matrix.

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Cationic homo-and co-polymerization of indene (Ind), styrene (St), limonene (Lim), and 5-ethylidene-2-norbornene (ENB) was performed with AlCl 3 in dichloroethane at À20°C under inert N 2 . The aim of this work is to investigate the effect of the reaction conditions on the molecular weight of polyindene (PInd) obtained by cationic polymerization with AlCl 3 without an electron donor, and also to determine the effect of the use of cyclic diolefin comonomers on the polymer properties. The polymers were synthesized at a monomer/catalyst molar ratio (MR) of 100; St and Lim showed the highest and lowest reactivity, respectively. The polymers were characterized by 13 C and 1 H NMR spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, size exclusion chromatography, differential scanning calorimetry, and thermogravimetric analysis. PInd with a number average molecular weight (M n ) of 45 Â 10 3 g/mol and a glass transition temperature (T g ) of 207°C was obtained, whereas only oligomeric polylimonenes were obtained. Cyclic diolefins depressed both the M n and T g values of the Ind-copolymers. There was a dramatic decrease in the M n of the polymers: those obtained at a MR of 1:1 in the feed presented M n values lower than 10 4 g/mol, with the exception of poly(Ind-co-ENB), which is cross-linked. Poly(Ind-co-Lim) with lateral double bonds, a comonomer content of 1 to 20 mol%, and T g values in the range of 140-200°C were obtained.