Enhanced Impact Strength of Recycled PET/Glass Fiber Composites

In this paper, we report a study on the effects of different ethylene copolymers in improving the impact strength of a fiber-reinforced composite based on a recycled poly(ethylene terephthalate) (rPET) from post-consumer bottles. Different ethylene copolymers have been selected in order to evaluate the effects of the polar co-monomer chemical structure and content. The composite mixtures were prepared via melt extrusion, and the samples were manufactured by injection molding. Impact strength was evaluated using Izod tests, and a morphological study (FESEM) was performed. As a result, a composite with substantially improved impact properties was designed. This study demonstrates that a post-consumer PET from the municipal waste collection of plastic bottles can be successfully used as a matrix of high-performance, injection-molded composites, suitable for use in the automotive sector, among others, with no compromise in terms of mechanical requirements or thermal stability.

PHYSICOMECHANICAL PROPERTIES OF NANOCOMPOSITES BASED ON COPOLYMERS OF ETHYLENE WITH α-OLEFINS AND CLINOPTILOLITE

The results of studying the effect of clinoptilolite concentration on the properties of nanocomposites based on of ethylene with butylene and of ethylene with hexene copolymer are presented. The effect of clinoptilolite particle size on ultimate tensile stress, elongation at break, flexural modulus, heat resistance, and melt flow index of composites was studied. It is shown that nanocomposites based on ethylene copolymers are characterized by higher values of physicomechanical properties. The additional use of ingredients such as alizarin and calcium stearate contributes to a significant improvement in the complex of properties of nanocomposites based on ethylene copolymers and clinoptilolite

Thermal behavior of ethylene copolymers with di- and tri-alkenylsilsesquioxane comonomers synthesized by post-metallocene catalysts

This paper reported thermal properties of ethylene copolymers with di- and tri-alkenylsilsesquioxanes (POSS) synthesized by bis(phenoxy-imine) Ti, Zr, V, and V salen-type complexes. Ethylene copolymers with multi-alkenyl POSS obtained by such complexes contain multi-alkenyl POSS incorporated into the polymer chain as a side group. They were characterized by different thermal behavior depending on the kind of multi-alkenyl POSS comonomer, and type of the catalyst used, as well as polymerization conditions and thus the structure of the copolymer chain. Ethylene/POSS copolymers differed in incorporation of POSS into the polymer chain, content of specific unsaturation groups, and molecular weight, as well as heterogeneity of polymer chain compositions. The incorporation of multi-alkenyl POSS into the polymer chain affected melting and crystallization processes of copolymers in different ways. The POSS units could act as a nucleating agent of macromolecules. The increasing POSS content in E/POSS copolymers resulted in increasing thermal stability of obtained products, regardless of the kind of multi-alkenylsilsesquioxanes used. Thermal stability of such copolymers increased with decreasing content of trisubstituted vinylene groups (internal saturations) as well. The highest improvement of thermal stability over 85 °C in comparison with PE was observed in case of E/POSS copolymers synthesized by bis(phenoxy-imine) zirconium catalyst. The composition heterogeneity of E/POSS copolymers was found to affect markedly thermal stability of E/POSS copolymers.