Boehmite alumina nanoparticles are added to PP‐g‐MAH‐compatibilized blends of PA 12 and PP to study the effects of nanoparticle loading in the resulting composites. WAXD and SEM data suggest that the nanoparticles enhanced the coalescence of PP. DSC, DMA, and TGA reveal that the final properties such as crystallization temperature, flexural storage modulus, thermal degradation temperature, etc., improve with increasing nanoparticle loading for blend/based composites. FTIR results show that the nanoparticles interfere with the interfacial activity at 5 wt% nanoparticle loading. All results are compared between the neat polymers and the compatibilized blend and show that despite a slight increase in dispersed‐phase domain size, all other properties improve with the addition of AlO(OH).

A composite of boehmite alumina nanoparticles and a PP/PA12 blend is prepared. WAXD and SEM suggest that a low filler loading enhances the coalescence of PA12, whereas a higher loading reverses the situation. DSC, DMA and TGA reveal that the final properties of the blend composites such as crystallization temperatures, flexural storage moduli, or thermal degradation temperatures improve with increasing nanoparticle loading. The data are compared with the neat polymers and the compatibilized blend, and the results show that the compatibility increases only at high nanoparticle loading, and most of the thermal properties improve with increasing nanoparticle content in the blends. The presence of interfacial interactions between the polymer matrices and the filler was confirmed via FTIR.

The short chain branching distribution (SCBD) and thermal properties of ethylene/1‐pentene copolymers were studied using SEC‐FTIR and SEC‐HPer DSC. The copolymers, synthesized with Cp2ZrCl2/MAO, were fractionated using size exclusion chromatography (SEC). The infrared analysis of the fractions showed that the copolymers had—on average—higher 1‐pentene concentration in the low molecular weight range. Furthermore, the thermal properties of the SEC deposits of these copolymers on a Germanium disc were studied using high performance differential scanning calorimetry (HPer DSC). Single SEC separations were used to accumulate fractions in the microgram range that were directly analyzed with regard to their thermal properties, thus allowing us to study SCBD as well as thermal behavior simultaneously. When these fractions (with masses ranging from 10–80 μg) were analyzed using HPer DSC, good melting and crystallization temperature distributions were obtained, proving that HPer DSC can be used as a complementary method to SEC‐FTIR. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2956–2965, 2007

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Ethylene/1-pentene copolymers were prepared using a [(CO) 5 Wϭ C(Me)OZr(Cp) 2 Cl] (1)/MAO catalyst system. 1-Pentene incorporation in the copolymer was monitored using 13 C-NMR spectroscopic methods. The weight average molecular weights (M w ) of the copolymers were between 142,000 and 629,000 g/mol, with polydispersity indexes (PDIs) ranging from Ϸ 2 to 90, as analyzed by size exclusion chromatography (SEC). Melting and crystallization temperatures, determined using differential scanning calorimetry (DSC) and crystallization analysis fractionation (CRYSTAF), decreased linearly as the amount of 1-pentene in the copolymer increased. SEC-FTIR revealed that the 1-pentene is predominantly incorporated in the low molecular weight fraction.