Preparation Of High-performance SiO₂/NR Tire Tread Compound Based On SiO₂ Surface Modification Technology

In green tires,when SiO₂is used in large quantities,it needs to be used together with a silane coupling agent.However,the occurrence of silanization reaction requires specific conditions(temperature and time),and VOC gas will be generated during the chemical reaction,and it needs to be guaranteed by the heat preservation section.High reaction rate not only requires high processing technology and pollutes the environment,but also increases energy consumption during processing.Based on this background,this paper studies the use of a green and efficient modifier to replace the traditional silane coupling agent bis[?-triethoxysilylpropyl]disulfide(Si-75)modified SiO₂(ST@SiO₂)to prepare pre-modified SiO₂(M@SiO₂)to develop green,high-performance,low rolling resistance tire treads.On the basis of M@SiO₂,graphene(GE)and carbon nanotubes(CNT)were added to prepare the loading filler(CTGS),and the effect of CTGS on the functionality(electrical and thermal conductivity)and other properties of the tire tread compound was studied.First,the non-ionic surfactants Tween-80(TW),oleylamine(YA),Span 80(SB),oleic acid amide(YSXA)and Tween-80 and oleylamine were formulated in a 1:1 ratio(WA)completely replaced the traditional silane coupling agent modified silica,and systematically analyzed the infrared spectrum,thermogravimetric spectrum,contact angle,specific surface area,scanning electron microscope and sedimentation volume of the modified silica,The optimal modifiers TW,YA,WA were selected according to the macroscopic properties of the composites.By focusing on comparing the comprehensive properties of M@SiO₂/NR and ST@SiO₂/NR,TW@SiO₂/NR,YA@SiO₂/NR and WA@SiO₂/NR composites were found to have excellent properties such as high physical and mechanical properties,high wear resistance and low rolling resistance.among which WA@SiO₂/NR has the best comprehensive performance(mechanical strength 29.13MPa,rolling resistance tan?@60?value 0.063,energy consumption 35.93KJ),compared with ST@SiO₂/NR(mechanical strength 26.49MPa,rolling resistance tan?@60?value 0.100,energy consumption 42.55KJ),mechanical strength increased by 10.8%,rolling resistance and energy consumption decreased by37.0%and 18.4%,respectively.When TW and YA are compounded to modify SiO₂in a ratio of 1:1,it can not only synergistically modify silica,but also effectively prolong the scorch time of YA@SiO₂/NR composites and improve the reversion phenomenon;in addition,compared with SiO₂/NR composites prepared by other commonly used silanecouplingagents(Bis-(?-triethoxysilylpropyl)tetrasulfide(Si-69),?-aminopropyltriet hoxysilane(KH550),?-glycidoxypropyltrimethoxysilane(KH560),?-Methacryloxypropy ltrimethoxysilane(KH570)),YA@SiO₂/NR and WA@SiO₂/NR composites have higher physical and mechanical properties and lower rolling resistance,indicating the superiority of YA and WA in applications.Secondly,due to the phenomenon of reversion and scorch in the M@SiO₂/NR composites prepared by TW,YA and WA,therefore,the reversion time and scorch time of M@SiO₂/NR composites were adjusted by adding anti-reversion agent KA9188 and adjusting the compound ratio of TW and YA.After the addition of KA9188,the reversion time of the M@SiO₂/NR composites was effectively prolonged,and the reversion performance of the TW@SiO₂/NR composites was improved most obviously,from 42.88 min to 74.78 min.Under the premise of the existence of KA9188,adjusting the ratio of TW and YA in the WA@SiO₂/NR composite can effectively increase the scorch time of the WA@SiO₂/NR composite,and also improve its reversion performance.When the ratio of TW and YA is 3:1,the WA@SiO₂/NR composite has the best reversion performance and scorch performance.The reversion time increases from 36.75 min to 41.88 min,and the scorch time increases from 15.02 min to 18.4min.Finally,in order to endow the M@SiO₂/NR composite with a certain functionality,on the basis of M@SiO₂,the?-?conjugation between tannic acid(TA)and GE(or CNT)was used for GE(or CNT))to carry out surface functionalization treatment,and the loading filler(CTGS)of GE(or CNT)and M@SiO₂was prepared by using the polyhydroxyl structure on the surface of TA and the functional group of the M@SiO₂surface modifier molecule or the hydrogen bond of the silanol group.In order to realize the co-dispersion of GE(or CNT)and M@SiO₂rubber matrix.Among them,using carbon nanotubes as carbon materials and oleylamine as"molecular bridges",the prepared CTGS4/NR composites have the best electrical and thermal conductivity,and the electrical conductivity of the composites is increased from the original 2.321*10^-6S.m^-1to 4.111*10^-4S.m^-1;the thermal conductivity is increased from the original0.2476 w/m.k to 0.2615w/m.k,and the physical and mechanical properties,rolling resistance,wear and fatigue temperature rise properties can reach the requirement of original ST@SiO₂/NR composites.