Study of the features of vulcanization and the character of vulcanization structures of nitrile butadiene rubber

The study investigated how temperature affects the cross-linking process in nitrile butadiene rubber, specifically in binary systems composed of SKN-40 with hexachloroparaxylene and with epoxy resin.Cross-linking, a crucial step in elastomer processing, determines the final mechanical and chemical properties of the rubber.Infrared (IR) spectroscopy was used to analyze changes in the molecular structure of the SKN-40+hexachloroparaxylene and SKN-40+epoxy resin systems during thermal treatment.The distribution of double bonds in the nitrile butadiene rubber matrix was assessed by measuring the optical densities of absorption bands at 967, 912, and 750 cm -1 .These bands are characteristic of different types of unsaturation within the elastomer, providing insight into how cross-linking agents interact with the polymer backbone.Thermal treatment at 150C for 40 min led to significant cross-linking in both systems.The number of cross-links formed was calculated to be 1.0510 mol/cm for the SKN-40+hexachloroparaxylene system and 0.6610 mol/cm for the SKN-40+epoxy resin system, indicating a higher cross-linking efficiency of hexachloroparaxylene under the given conditions.The effectiveness of cross-link formation was further validated by evaluating changes in spatial grid parameters, which reflect the network structure of the cross-linked rubber.These findings demonstrate that crosslinking efficiency is highly dependent on both the chemical nature of the cross-linking agent and the processing temperature, with hexachloroparaxylene showing superior performance in enhancing the structural integrity of nitrile butadiene rubber under heat