Metal ion-accelerated poly(catechol/polyamine) deposition and epoxy-functionalized modification: building bridges between aramid pulp and carboxylated nitrile butadiene rubber/cis-polybutadiene rubber

In this work, we prepare epoxidized aramid pulp (AP) by grafting ethylene glycol diglycidyl ether (EGDE) onto the surface of AP via poly catechol/polyamine (PCPA). Subsequently, we premix the epoxidized AP with carboxylated nitrile butadiene rubber (XNBR) to induce a chemical reaction with the carboxyl group in XNBR. The carboxylated nitrile butadiene rubber/cis-polybutadiene rubber/aramid pulp (XNBR/BR/AP) composites are prepared by mechanical blending. Water contact angle, FTIR, and XPS confirm the grafting of EGDE onto AP via an epoxy group ring-opening reaction. The rheological performance results indicate that the addition of EGDE decreases the curing time of the composites and increases the degree of cross-linking of the composites. The compatibility between AP and rubber is analyzed by SEM, and it is deduced that the interfacial bonding between AP and composite is enhanced by EGDE. The tensile strength, tear strength, abrasion resistance, and solvent resistance of the composites are significantly improved after EGDE modification. RPA results show that the modified AP is uniformly dispersed in the composites and reduces the rolling resistance of the composites. A new and effective strategy is provided for the surface functionalization of aramid pulp meal, which has a wide range of rubber industry applications. Highlights: Composite mechanical properties increase with increasing EGDE content. Rheological properties of composites improved by EGDE incorporation. EGDE improves filler dispersion, reduced rolling resistance of composites. Increased interfacial bonding between AP and rubber due to EGDE.