Surface modification of silica with polymethylmethacrylate-co-methacrylic acid for enhancement of self-healing performance of natural rubber composites based on metal thiolate ionic network

Polymethylmethacrylate-co-methacrylic acid (PMMA-co-MAA) was utilized for surface improvement of silica to be used as reinforcement in self-healing natural rubber based on metal thiolate ionic network. The amount of PMMAco-MAA was varied at 1, 3, and 5 wt% of silica content and the optimized PMMA-co-MAA was utilized to investigate the self-healing NR/silica composites at different filler loading (5, 10, 20, and 30 phr). The graft polymerization of PMMA-co-MAA on silica was confirmed using FTIR spectroscopy and grafting percentage was determined by thermogravimetric analysis (TGA). Intermolecular diffusion occurred at the fractured area was detected using a scanning electron microscope (SEM) and the results revealed that the composite tensile and tear performance increased 22%-70% with healing efficiency percentage ranging between 70% and 97% depending on the silica loading. KEYWORDS Methacrylic acid, modified silica, natural rubber composites, reversible ionic network, self-healing
1 | INTRODUCTION Natural rubber (NR) is an important raw material used in numerous industries, including the automotive, sporting goods, medical, and electrical fields. Their exceptional qualities, including strong chemical [...]