Oil-Soluble and Core-Cross-linked Fibrous Nanofillers with Excellent Comprehensive Performances Generated by In Situ Cross-linking Polymerization-Induced Self-Assembly

Reinforcement of polymeric materials by incorporating rigid nanofillers (especially nanofibers) is a promising strategy, which mainly relies on the elaborate design of nanofillers. Herein, we report an oil-soluble and core-cross-linked fibrous nanofiller with superior comprehensive properties. In situ cross-linking polymerization-induced self-assembly (PISA) in mineral oil is demonstrated to be a powerful strategy for producing oil-soluble nanofibers with excellent reproducibility (100% in 10 repeated experiments). The oil-soluble stabilizer enables good compatibility of the nanofibers with various hydrophobic polymer matrices, and the core-cross-linked structure endows the nanofibers with robust stability to resist the severe processing environment (high temperature and high shearing) of fabricating polymer–nanofiller composites. The nanofibers show superior reinforcement effects on the polymer–nanofiller composites but without the expense of transparency, recyclability, and self-healing ability. With only 1 wt % dosage of the nanofibers, the tensile stress, elongation, and toughness of the polymer–nanofiller composites increased by approximately 2.6, 3.5, and 7.2 times, respectively. The oil-soluble and core-cross-linked nanofibers based on the in situ cross-linking PISA strategy are attractive candidates of nanofillers to reinforce plastics, gels, or elastomers in various industrial applications, which not only have excellent comprehensive performances but also meet the requirements of sustainable development.