Study on the Modification of Nitrile-Butadiene Rubber by Halloysite Nanotube-Oleylamine Graft and Its Low-Temperature Resistance Performance

This study pioneers the grafting of oleylamine onto halloysite nanotubes (HNTs) to synthesize a low-temperature composite modifying agent for rubber (HNTs-Y). It enables the synergistic regulation of the low-temperature performance of nitrile butadiene rubber (NBR) via a “plasticization-reinforcement” mechanism, addressing both the migration propensity of conventional small-molecule plasticizers and the insufficient low-temperature modification efficacy of pristine HNTs. This work thereby provides a novel multifunctional modification strategy for optimizing the low-temperature performance of elastomers. Experimental results demonstrate that HNTs-Y significantly enhances the low-temperature resistance of NBR. Specifically, at a loading of 6 phr, the hardness difference of 4 # NBR between −40°C and 40°C is reduced by 45.2% compared to 1 # NBR, indicating improved hardness stability over a broad temperature range. Additionally, the tensile strength of 4 # NBR at −20°C is 79% higher than that at 20°C and 77% higher than that of 1 # NBR, reflecting enhanced resistance to tensile fracture under low-temperature conditions. Furthermore, with the increase in HNTs-Y content, the brittle temperature ( T b ) and glass transition temperature ( T g ) of NBR exhibit an overall downward trend. For 4 # NBR, the T b reaches −52°C and the T g is −29.5°C, manifesting excellent low-temperature resistance.