MISCIBILITY BEHAVIOR OF PVC POLYMETHACRYLATE BLENDS - TEMPERATURE AND COMPOSITION ANALYSIS

The miscibility behaviour of poly(ethyl methacrylate) (PEMA), poly(n-propyl methacrylate) (PPMA), poly(n-butyl methacrylate) (PBMA), and poly(n-amyl methacrylate) (PAMA) with poly(vinyl chloride) (PVC) was investigated using differential scanning calorimetry. All of the blends are miscible, i.e. they show a single glass transition temperature, when subjected to an appropriate thermal history. A lower critical solution temperature was detected in PVC/PBMA and PVC/PAMA blends, but not in PVC/PEMA and PVC/PPMA blends (although it must exist at temperatures higher than 200-degrees-C, which was not accessible experimentally due to severe degradation of PVC). These observations lead to the conclusion that there is a miscibility window in terms of the polymethacrylate structure; the greater degrees of miscibility are found in the PEMA and PPMA blends.