Synergistic Effect of Copper Sulfate and Tetramethylthiuram Monosulfide Induced Metal‐Coordination Cross‐Linking in Nitrile–Butadiene Rubber

Abstract

The cross‐linking microstructure formed by the metal‐coordination bonds provides excellent properties for rubber materials. Copper sulfate (CuSO4) and tetramethylthiuram monosulfide (TMTM) are successfully compounded with nitrile–butadiene rubber (NBR) to fabricate vulcanizates by the coordination cross‐linking. The curing characteristics, mobility of macromolecular segment, mechanical properties, morphology analysis, swelling properties, and dynamic features under cyclic compression of the vulcanizates are investigated systematically. The results indicate that the microstructure of 3D cross‐linking is held together by the metal‐coordination bonds between Cu2+ and CN. The torque during static vulcanization, tensile strength, and cross‐linking density of the obtained NBR/CuSO4/TMTM vulcanizates are better than that of NBR/CuSO4 vulcanizates, which is attributed to the synergistic effect between the radicals formed by the splitting of TMTM under thermal activation and the Cu2+; moreover, the highly reactive [Cu(SnCNMe2)]•2+ complexes are formed by the synergistic effect and promote the coordination stability of NBR and CuSO4 effectively. The excellent tensile properties of the prepared NBR/CuSO4/TMTM vulcanizates via synergistic effect made the metal‐coordination cross‐linking attractive in the field of industrial application.

The effect of different forms of iron substances on the aging properties of carbon‐black filled natural rubber

“…Investigation of the role and mechanism of metal materials on rubber is important in not only developing combined polymer material, such as crosslinking by copper sulfate, [ 34 ] adhesion between rubber and brass‐plated steel wire in tire, [ 35 ] and but also studying mechanical and thermal properties of rubber materials. [ 36 ] NR‐based tire‐tread compound can be influenced by metal poisoning.…”

Synthesis of Diaryl Sulfides by Using Tetramethylthiuram Monosulfide (TMTM) as Organosulfur Source: A Practical C(sp2)−S Bond Construction

“…[21] Due to its unique structure, TMTM can easily form a metal-coordinated crosslinked structure with metal, which provides excellent properties for rubber materials. [22] In addition, this sulfidation reagent can preferentially generate monosulfur structures to affect the sulfidation rate and efficiency, and ultimately promote the progress of the sulfidation reaction. [23] We previously reported the synthesis of benzoxazoles using the thiocarbonyl moiety of tetramethylthiuram monosulfide [21c] (Scheme 1d).…”

“…As a rarely reported organosulfurization reagent, tetramethylthiuram monosulfide (TMTM) has aroused our research interest [21] . Due to its unique structure, TMTM can easily form a metal‐coordinated cross‐linked structure with metal, which provides excellent properties for rubber materials [22] . In addition, this sulfidation reagent can preferentially generate monosulfur structures to affect the sulfidation rate and efficiency, and ultimately promote the progress of the sulfidation reaction [23] .…”

One-Step Simultaneous Synthesis of an Industrially Important Rubber Accelerator and a Lubricant Additive by Disulfide Bond Contraction

“…Although the overall production is not as huge as that of commodity chemicals, TMTM is considered a key chemical product in the rubber industry as it carries unique advantages, including no color change during vulcanization, reduced pollution, a high sulfurization speed, and excellent scorch safety. [5][6][7] It is often applied in association with aldehyde-ammonia and guanidine-type accelerators to enhance their activities or used as a secondary accelerator for sulfonamide and thiol accelerators. 8 Besides its wide utility in the rubber industry, TMTM is also a versatile reagent in organic synthesis.…”