Peroxide crosslinking of rigid poly(vinyl chloride)

Peroxide crosslinking of unplasticised poly(vinyl chloride), PVC with trimethylolpropane trimethacrylate (TMPTMA) has been investigated. Formulations used in this work contained a nontoxic lead free stabiliser and showed good colour and heat stability. The samples have been examined by differential scanning calorimeter(DSC) and tensile properties at room temperature and at 130oC were measured. Gel content or tetrahydrofuran (THF) insoluble material was measured as an indication of crosslinking. It is shown that premature crosslinking can be avoided during processing. It was found that 190oC was the optimum processing temperature for maximum gel content. The residual unsaturation was monitored using FTIR.