Mechanical and Aging Performances of Hydrogenated Nitrile Butadiene Rubber/Polyvinyl Alcohol Fibers ( <scp>HNBR</scp> / <scp>PVA</scp> ) Composites Prepared Using Various <scp>PVA</scp> With Incremental Diameter and Length

ABSTRACT This study utilized polyvinyl alcohol fibers (PVA) as reinforcing agents to prepare a series of hydrogenated nitrile butadiene rubber/polyvinyl alcohol fibers (HNBR/PVA) composites by using a physical mixing technique. Effects of the diameter (20–30 μm), length (1 and 2 mm), and content of PVA on the properties of HNBR/PVA composites were systematically investigated through rheological, mechanical, and aging tests. The results demonstrated that, compared to the pure HNBR, the total crosslink level of HNBR/PVA composites increased by roughly 15%, and the vulcanization efficiency enhanced without jeopardizing the processing safety. The integration of PVA altered the tensile behaviors of HNBR/PVA composites remarkably, resulting in a considerable enhancement in the modulus at initial strain. Notably, the HNBR/PVA20‐2‐5 composite (20 μm in diameter, 2 mm in length and 5 phr in content of PVA) exhibited remarkable dimensional stability, which could be reflected by the 288% increase in modulus at 100%. The mass change rate of HNBR/PVA composites aged in IRM903 reference oil at 150°C remained consistently lower than that of pure HNBR, underscoring the enhanced oil resistance. It can be expected from this work that the high‐performance rubber products based on HNBR/PVA composites could be developed, such as the high‐temperature oil‐resistant sealings and other sealings bearing substantial mechanical loads.