Monica Tanniru; Pankaj Tambe
Abstract
The automotive industry has a significant need for composites made of high impact strength polymer blends. Melt-mixing was used in this work to reinforce hollow glass microspheres (HGMs) with 50:50 polypropylene/ polyamide 6 (PP/PA6) blends. Using FTIR spectroscopy, it is observed that the 50PP50PA6 ...
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The automotive industry has a significant need for composites made of high impact strength polymer blends. Melt-mixing was used in this work to reinforce hollow glass microspheres (HGMs) with 50:50 polypropylene/ polyamide 6 (PP/PA6) blends. Using FTIR spectroscopy, it is observed that the 50PP50PA6 blend is compatibilized with maleated PP, producing a reactively compatible blend. The compatibilization process has refined the morphology of the 50PP50PA6 blend. Additionally, the incorporation of HGMs into the 50PP50PA6 blend produced a finer blend morphology, which helped to enhance the crystallinity of the polymer phase and mechanical properties to the maximum. The tensile modulus and impact strength of a 50PP50PA6 blend with maleated PP that contains 3 wt.% HGMs are better than those of a neat blend by 15.6% and 90.1%, respectively. Fractography was used to identify the fracture mechanism which reveals the retention of droplets over the surface of impact specimens of HGMs-filled compatibilized PP/PA6 blend. When 50PP50PA6 blend with and without maleated PP is filled with HGMs, rheological characterization shows that the blend viscosity has decreased, indicating improved processability. Dynamic mechanical analysis (DMA) revealed that the incorporation of HGMs into the 50PP50PA6 blend enhances the storage modulus.
Catalysis
Maria Carmela Sacchi; Simona Losio; Paola Stagnaro; Giorgio Mancini; Luca Boragno; Stefano Menichetti; Caterina Viglianisi; Sara Limbo
Abstract
Some innovative solutions are proposed to the problem of the unavoidable physical migration of antioxidants from plastic films for packaging, in order to minimize the consequent undesirable effect of food contamination. In previous exploratory tests, phenolic antioxidant co-units were achieved and incorporated ...
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Some innovative solutions are proposed to the problem of the unavoidable physical migration of antioxidants from plastic films for packaging, in order to minimize the consequent undesirable effect of food contamination. In previous exploratory tests, phenolic antioxidant co-units were achieved and incorporated into polyethylene chain and now the work is extended to create new families of polymeric additives properly designed for specific material. An effective route was designed to synthesize the functionalized comonomer, analogues of commercial 2,6-t-butyl-4-methoxy-phenol (BHA), containing eight methylene units as spacer between the aromatic ring and the polymerizable olefinic double bond (C8). Ethylene/1-hexene/C8 terpolymers, with 1-hexene concentration in the typical range found in commercial polyethylene grades, and propylene/C8 copolymers with microstructure similar to those of commercial packaging polypropylenes were produced. A careful 13C NMR study was conducted for the precise determination of the functionalized comonomer content on all terpolymer and copolymer samples. The samples melt blended with additive-free commercial LDPE and PP matrices, individually, were analyzed in terms of thermal and thermo-oxidative stability and compared with LDPE and PP films containing the traditional BHA additive analogue. The results demonstrate that, in either way, the polymeric additives exert a very positive effect on the degradation temperature of the polymeric matrices, retarding the thermo-oxidative sequence of reaction.
