Flow and structure of compatibilized Nylon12/natural rubber blend with functional copolymer

Abstract

Polyamide12 (Nylon12)/natural rubber (NR) blend was prepared by melt mixing in a Brabender mixer using polystyrene/maleated natural rubber (PS/MNR) copolymer as a reactive compatibilizer. The influence of compatibilizer loading (1, 3, 5, 7, and 10 phr), shear rate (10–500 s−1), and temperature (200–220°C) on the flow properties (i.e., shear viscosity ( η), power law index, flow activation energy ( Ea), and extrudate swell) of (Nylon12/NR)/(PS/MNR) blends was investigated. The blends showed pseudoplastic behavior from an evident increase of shear stress and a reduction of η with increasing shear rate. The values of η and Ea of the blends were also found to increase with the compatibilizer loading. It suggests that PS/MNR copolymer functioned properly and enhanced the compatibility and interfacial interaction between Nylon12 matrix and NR domains via the formation of amide and succinimide linkages at the interfaces. This reactive compatibilization also caused in a reduction of extrudate swell apparently due to slower elastic recovery of polymer chains.