Thermal/Peroxide Induced Degradation and Maleation of Polypropylene by Reactive Extrusion

Abstract

Abstract Experimental studies of three types of reactive extrusion are reported: thermal degradation, peroxide induced degradation and maleation of polypropylene for intermeshing modular co-rotating and counter-rotating twin screw extruder. The studies were carried out in a modular intermeshing twin screw extruder which can be co-rotating or counter-rotating and possesses different screw configurations. Generally thermal degradation was found to be more effective in intermeshing counter-rotating twin screw extruders when similar screw configurations and operating conditions are used. For peroxide induced degradation both counter-rotating and co-rotating machines performed about the same. For the maleation reaction the co-rotating twin screw extruder achieves higher conversions than the counter-rotating machine with all screw configurations and conditions studied. It would appear that the intermeshing counter-rotating twin screw extruder operates at a higher temperature and has poorer mixing characteristics than the co-rotating machine. Differences between the co-rotating and counter-rotating machines decrease with introduction of kneading disc blocks.