Modified talcum as crosslinking agent for polyolefins

Abstract

The aim of this study is to investigate the modification of talcum and its support as crosslinking agent for polyolefins. To improve the crosslinking of polyolefin chains a thermal initiator is linked to the talcum surface. During the extrusion process the initiator decomposes and radicals are formed. These radicals will start and support crosslinking between the polymer chains. To produce crosslinked polymers, two steps were necessary. The first step was the modification of the mineral filler. For that purpose alkoxysilanes were grafted onto the talcum surface. After that, the initiator was linked to the silanes grafted onto the talcum surface. To prove the active molecular components on the particles, the silanized and modified talcums were characterized with different measurement methods such as x-ray photoelectron spectroscopy, infrared spectroscopy and thermogravimetric measurement. The second step were the crosslinking experiments with the modified talcum in polyolefins. Compounds of polyolefins and modified talcum were kneaded, plates were compression molded and analyzed with a plate/plate rheometer regarding their crosslinking behavior.