Study On Zn?MAA?₂/S Composite Vulcanization System Of High Performance Natural Rubber

As a kind of unsaturated carboxylic acid salts of rubber additives,zinc dimethacrylate?Zn?MAA?₂?is as the crosslinking agent and reinforcing agent of rubber products in peroxide curing system at the first.It makes rubber products get high modulus,high strength,good wear resistance,excellent heat aging resistance.Due to the special chemical structure,zinc dimethacrylate has high activity in the presence of free radicals.However,for natural rubber,sulfur curing system is the most important curing system.It is very significant for Zn?MAA?₂ to applicate in natural rubber vulcanization to improving the properties of natural rubber.This paper studies the effect on sulfur curing properties of natural rubber under the condition of ZnO and a small amount of Zn?MAA?₂?0.45phr-2.25phr?coexistence,and put forward the mechanism.Then inspected the Activation of a small amount Zn?MAA?₂?2.25phr-8phr?in the sulfur vulcanized natural rubber without ZnO and the properties influence of vulcanized rubber.Finally,preliminary discuss the Zn?MAA?₂ modified sulfur system?Zn?MAA?₂/S^*?enhanced adhesion of natural rubber and brass plated steel cord.The results show that the presence of ZnO a small amount of Zn?MAA?₂ can significantly improve the hardness,tensile stress and crosslink density,reduce the compression heat with the sulfur curing activation energy of natural sulfur vulcanized rubber.When using two benzoyl peroxide?BPO?pretreatment of sulfur and Zn?MAA?₂,the physical and mechanical properties and the compression heat performance of vulcanizated rubber decreased slightly.This shows that the reaction degree of Zn?MAA?₂ and sulfur is enhanced,Part of the sulfur loss.This results in a slight decrease in the physical and mechanical properties of vulcanized natural rubber.Increase the amount of sulfur in rubber which is containing Zn?MAA?₂,which can obtain more excellent physical and mechanical properties of vulcanized rubber by vulcanization.On the condition of coexistence of ZnO and Zn?MAA?₂,in M,DM,NOBS and DZ four accelerators,DM can give higher MH-ML and curing rate;DZ has a more obvious and delayed longer scorch safety period.The most excellent mechanical properties for NOBS is given.M can give a better performance of thermal oxidative aging.The compression fatigue temperature rise of NOBS is the highest,and the compression fatigue temperature of M is the lowest;For no ZnO system,the activation activity of Zn?MAA?₂ is similar to that of ZnO,and can give a better scorch safety,faster curing rate and higher curing degree,higher crosslinking density,lower activation energy than ZnO.Physical and mechanical properties and thermal aging performance are also more excellent.Better dynamic fatigue properties can be obtained in the experimental range.Under the scanning electron microscope can be observed after curing Zn?MAA?₂ in the rubber the aggregation state changed obviously,which the particle size is significantly smaller,and the particle size of Zn?MAA?₂ in the vulcanizated rubber was obviously less than ZnO's.Finally,activator pretreatment sulfur and Zn?MAA?₂ obtains Zn?MAA?₂/S^* composite,which can be given higher adhesive force between natural rubber and brass plated steel cord.The amount of activator and Zn?MAA?₂/S^*composite has an optimal value,which makes the best adhesion;The addition of stearic acid is not conducive to the adhesion of Zn?MAA?₂/S^* composite vulcanized natural rubber and copper plated steel cord.