Features of PVC/ABS compositions filling

Abstract

The work is devoted to the filling of PVC (polyvinyl chloride) compositions modified with ABS (acrylonitrile-butadiene styrene) in a wide concentration range, intended for the production of profiles and moldings of various functional purposes, with short-fiber basalt fiber. Powdered samples were made by extrusion (in the form of flat profiles) and by thermoplasticizing on rolls (in the form of films). Introduction of 10-40 phr ABS in PVC formulation makes it easier to recycle the composition. Similar situation is observed when these compositions are filled with basalt fiber, which leads to insignificant decrease of MFR (melt flow index) and thermal stability, which in general does not reflect negatively on melt flow conditions, at the same time extrudate swelling index decreases by 10-15%, which indicates possibility to provide products with more precise geometric dimensions. The change in the supramolecular structure was evaluated by thermomechanical tests and by energy dispersive analysis using electron microscopy data. Thermomechanical analysis showed that the presence of large doses of ABS has a positive effect on the technological properties, leading to an earlier development of highly elastic deformations and a decrease in the yield point of the compositions. Basalt fiber contributes to an insignificant decrease in the value of high elastic deformations and an increase in the density index of meshing knots. Energy dispersion analysis has shown that introduction of basalt fiber leads to formation of homogeneous structure of PVC at lower concentrations of ABS in the composition, influencing on increase of melt flowability and thermal stability. Improved technological properties of PVC compositions filled with short-fiber basalt fiber, modified with different concentrations of ABS, allow to recommend them for production of a wide range of profile and molded products.