Compatibilization of a Crystalline Polymer Blend by Molecular Design and Control of Crystallization

Managing end-of-life plastics is a challenging problem for a variety of reasons, including the complexity of recycling mixed waste streams. Most polymer pairs don’t mix, and any product made from such a mixture will exhibit poor properties. These polymer mixtures can be enhanced by their compatibilization with proper polymeric interfacial modifiers. A compatibilizer strengthens the interface between immiscible polymers to stabilize the blend. Previous research by our group has examined the ability of chlorinated polyethylene (cPE) to compatibilize PVC and polyolefin elastomers (POE). However, the correlation of cPE and POE crystallinity on the compatibilization process is not fully understood. We will report on the correlation of annealing temperature to the strength of a POE/PVC interface that is compatibilized with a blocky cPE. These results show a correlation of interfacial strength to the rate of crystallization of each component, i.e., where the annealing temperature sits relative the Tg and Tm of the blend components. This presentation will therefore provide insight into the molecular design and thermal processing protocols needed to rationally control crystallization for phase separated crystalline polymer blends, including those that are most relevant for mixed waste streams in polymer recycling.