Melt processing and property testing of a model system of plastics contained in waste from electrical and electronic equipment

Abstract

In the present research, blending of polymers used in electrical and electronic equipment, i.e. acrylonitrile–butadiene–styrene terpolymer, polycarbonate and polypropylene, was performed in a twin-screw extruder, in order to explore the effect process parameters on the mixture properties, in an attempt to determine some characteristics of a fast and economical procedure for waste management. The addition of polycarbonate in acrylonitrile–butadiene–styrene terpolymer seemed to increase its thermal stability. Also, the addition of polypropylene in acrylonitrile–butadiene–styrene terpolymer facilitates its melt processing, whereas the addition of acrylonitrile–butadiene–styrene terpolymer in polypropylene improves its mechanical performance. Moreover, the upgrading of the above blends by incorporating 2 phr organically modified montmorillonite was investigated. The prepared nanocomposites exhibit greater tensile strength, elastic modulus and storage modulus, as well as higher melt viscosity, compared with the unreinforced blends. The incorporation of montmorillonite nanoplatelets in polycarbonate-rich acrylonitrile–butadiene–styrene terpolymer/polycarbonate blends turns the thermal degradation mechanism into a two-stage process. Alternatively to mechanical recycling, the energy recovery from the combustion of acrylonitrile–butadiene–styrene terpolymer/polycarbonate and acrylonitrile–butadiene–styrene terpolymer/polypropylene blends was recorded by measuring the gross calorific value. Comparing the investigated polymers, polypropylene presents the higher gross calorific value, followed by acrylonitrile–butadiene–styrene terpolymer and then polycarbonate. The above study allows a rough comparative evaluation of various methodologies for treating plastics from waste from electrical and electronic equipment.