CHAIN EXTENSION OF LOW VISCOSITY PA 66 IN REACTIVE EXTRUSION PROCESS IN ORDER TO EXTRUDE THICK-WALLED PIPES

摘要

The aim of this study is to increase the complex viscosity of low viscosity polyamide 66 (PA 66) by means of a chain extension process. The technical goal of the process is to extrude thick-walled pipes from chain extended PA 66 avoiding sagging effects. The influence of styrene maleic anhydride (SMA) and epoxide (EP) on chain extension of PA 66 were studied using a co-rotating twin-screw extruder. To evaluate the coupling effects of the different extenders on PA 66, the rheological and mechanical properties of the chain extended PA 66 were investigated. The extruded pipes, obtained from chain extended PA 66, featured a considerably improved wall thickness distribution.