High density poly(ethylene)/CaCO3 hollow spheres composites for technical applications

Abstract

Observed data in this study indicated creation of the combined plastic elastic mechanical behavior when spherical hollow sphere CaCO3 particles were used as a HDPE polymer matrix filler. It was found that with increasing filler concentration the corresponding increase of the Young's modulus of elasticity was accompanied with corresponding decrease of the upper yield point and elongation at break. Dynamic mechanical testing of the studied composites performed by means of the frequency dependent transfer damping function indicated lower stiffness of the filled HDPE composites in comparison to the neat polymer matrix. This founding corresponded with the strong effect of the filler particles on lowering the creation of the higher molecular conformational structures of the crystalline regions of the HDPE in favor to the amorphous parts. SEM analysis of the fracture surfaces showed typical elongation bands of high plasticity deformation regions characteristic with a typical shearing bands interpenetrated with clear cavities created around filler particles. Thermal analysis data showed minor change of the crystallinity with increasing filler particles content in the polymer composite matrix in such a way, that the higher amorphous phase content was found with increasing filler concentration. Creep behavior of the tested specimens indicated higher plasticity of the nanocomposites matrix in comparison with the virgin HDPE.