Mechanochemical degradation of the crosslinked and foamed EVA multicomponent and multiphase waste material for resource application

Abstract

Effects of mechanochemical degradation of the crosslinked and foamed ethylene-vinyl acetate copolymer (EVA) multicomponent and multiphase waste material in a solid state are studied with a HAAKE rheometer. The ruptures of chemical bonds in its net and stereo-structures are caused by external mechanical energy input by the Roller rotors of the HAAKE rheometer. A resource application method of the degradation product is obtained. The optimum mechanochemical degradation conditions are at 120–130 °C in a Roller rotor rotation speed range of 40–60 rpm for 24 min. Smaller polymer molecules have been generated so that the interfacial morphology, phase compatibility and plastic flow properties of the degradation product are all improved. The sol extracted from the degradation product is characterized with thermogravimetric analysis, gel permeation chromatography, nuclear magnetic resonance and Fourier transform infrared spectroscopy. Free radical reaction mechanisms are demonstrated in the degradation process. The degradation product partly replaces pure EVA in preparing the crosslinked and foamed material. Results show that the degradation product could be in resource application.