Effects of nano-Fillers and Process Conditions on the Microstructure and mechanicla Properties of MicrocellarInjection Molded Polyamide Nanocomposites.

摘要

This paper presents the effects of process conditions and nano-clay fillers on teh microstructure (namely,size,density,and distribution of microcells within samples) and theresultign mechanical properties of microcellular injection molded polyamide-6(PA-6) nanocomposite an dits neat-resin counterpart.Based onthe design of experiments (DOE) matrices,samples were molded at various supercriticalfluid(SCF) levels,melt temperatures,shot sizes,melt plastication pressures(MPP), and injection speeds.These samples were then subjected to scanning electron microscope(SEM) analysis,tensile testing,and impact testing.For both materials,the microstructure and the mechanical properties of the molded samples were found to be dependent on the process conditions and presence of nano-clay,which couldserve as microcell nucleating agent.At higher weight reductions,the nanocomposite samples exhibit much smaller microcells and higher cell densities than thoseobtained in the neat-resin samples.The SEM micrographs reveal noticeable differesin.A statistical design analysis was used to identify the optimal porcess couditions that would result in desirable cell size an ddensity and,thus,better mechanical properties.For example,thehighest tensile strengths have been observed atthe highest levels of shot size,MPP,injection speed,and SCF level,and at the lowest level of melt temperature.