Effects of compatibilizers in WPC in regard to their molecular properties

摘要

The aim of this work was investigate the effects of compatibilizers in WPC in regard to their molecular properties, i.e. maleic anhydride graft level and molecular weight. Test specimens with variations in wood content and (commercial) compatibilizer share and grade were produced via compounding using a co-rotating twin screw extruder and injection molding on a conventional injection molding machine. These specimens were tested for tensile strength and modulus (according to ISO-527), to yield basic information on the improvement effects of the compatibilizers on the mechanical properties. To retrieve the maleic anhydride graft content, a hot titration method was applied. For getting information about the molecular weight of the compatibilizer grades, we used the melt volume flow rate, recorded on a melt flow rate testing device. In conclusion, we found out, that not only the maleic anhydride graft content, but also the molecular weight show influences on the effectiveness of the different compatibilizer grades. Said effectiveness was characterized via different key factors, e.g. the maximum strength improvement, and can help to choose the right grade and amount of compatibilizer for specific applications.