Molding blends of silicone polymer / polypropylene with durable resistant to extreme conditions based on migration and compatibility of molecular chains

Abstract

Because of low surface energy, silicone polymers would easily peel off from polypropylene (PP) substrate as hydrophobic coatings and they are incompatible with PP in melt-blending process as well. Therefore, ethylene polymers modified with both silicone and alkane side-groups were prepared by nucleophilic substitution in this work. It was confirmed that these prepared polymers could migrate and aggregate to the surface of the blends at that melting temperature when blended with PP due to the low surface energy and high entropy of silicone side groups. Meanwhile, chain entanglement was achieved between alky side-groups of silicone polymers and polymer chain of PP by melt-blending process, so that the compatibility of the blends was improved and the bonding force of two polymers increased simultaneously. Accordingly, molding blends with stable and durable hydrophobility were successfully gained based on migration of silicone and entanglement of alkane and PP. It’s noticeable that the water contact angle of the blend remained to be about 106° from 113°, even soaking in acid (pH = 1) and alkali (pH = 14) solutions, deionized water and anhydrous ethanol, or under multiple strong frictions. This will provide a facile and effective strategy to endow general materials with durable antifouling properties directly by injection molding without additional coating.