Improving Abrasion Resistance of Rubber/Nanocellulose Composite Sheets

ABSTRACT Nanocellulose materials are promising candidates to partly replace petroleum‐based carbon black (CB) as fillers for rubber composites. This study considers the actual rubber manufacturing process in preparing nanocellulose‐containing and vulcanized (i.e., sulfur‐ or S‐crosslinked) natural rubber (NR) composite sheets. Their abrasion resistance, which is significant in actual applications, in addition to their normal properties, was investigated using S‐crosslinked NR/CB composite sheets as references. The S‐crosslinked NR/CB composite sheets showed higher tensile strengths and abrasion resistance than those of the S‐crosslinked nanocellulose‐containing NR composite sheets prepared under various conditions. However, the peroxide (PO)‐crosslinked NR/nanocellulose composite sheet exhibited higher tensile strengths and higher stress values at 20%, 50%, 100%, and 300% strain than those of the NR/CB composite sheets and an abrasion resistance similar to those of the NR/CB composite sheets. Therefore, the advantages of using nanocellulose as a filler were demonstrated by preparing NR composite sheets via PO‐crosslinking. Pulsed nuclear magnetic resonance is a useful tool for characterizing the network structures of composite sheets at the nano‐level, and the obtained spin–spin relaxation‐related data were well correlated with the macroscopic tensile properties and abrasion resistance of the composite sheets.