Polymer nanocomposites on the basis of low density polyethylene and dressed kaolin

Abstract

The influence of the organosilicon coupling agent — aminoethylaminopropyltrimethoxysilane — on the physicomechanical properties of nanocomposites based on a low density polyethylene and kaolin is considered. The kaolin nanoparticles with a size of 80-120 nm were obtained during the processing of the powdered mineral in a laboratory mill mark A-11 at a rotor speed of 30,000 rpm. The regularity of changes in the properties of the dressed polymer nanocomposites depending on the concentration of the filler and coupling agent is shown. For comparative analysis, composites with dressed and undressed filler were used. The results of the study showed that nanocomposites with dressed nanoparticles are characterized by relatively high values of ultimate tensile stress, elongation at break, and flexural strength. Only when the concentration of the filler is 20 wt.% and higher, there is a noticeable deterioration in strength and elongation at break of the composites. This is interpreted by the fact that in the process of crystallization and growth of spherulites most of the filler accumulates in the amorphous region which consists of a large number of “feed-through chains” determining the mechanism of formation of the “neck” under uniaxial tension. The increase in the proportion of filler particles in the inter-spherolite space is accompanied by the fact that the feed-through chains become “walled up” in amorphous space.