Enhanced Mechanical Properties of Natural Rubber by Block Copolymer-Based Porous Carbon Fibers

Nanosized particles have a large surface area to facilitate interfacial contact and thus are promising fillers for polymers. However, poor dispersion of nanoparticles limits the reinforcement effect. Herein, by rationally tailoring the internal porous structures, specific surface area, and surface chemistry, we prepared porous carbon fiber (PCF) filler from poly(acrylonitrile-block-methyl methacrylate) (PAN-b-PMMA) block copolymers. PCF had a three-dimensional porous network and provided improved filler–matrix interactions. Owing to the enhanced filler–matrix interlocking, large interfacial contact area, and strong interfacial affinity induced by nitrogen and oxygen doping, PCF was uniformly dispersed in rubber. Uncured nature rubber composites containing 5 parts of PCF per hundred parts of rubber (phr) showed 4.3 times higher Young’s modulus and twice the tensile strength at 300% strain compared to the neat rubber. PCF represents an effective reinforcing filler for polymers.