聚二甲基硅氧烷干法改性气相白炭黑及其应用研究  

Dry modification of fumed silica with polydimethylsiloxane and research on its application

作　　者：万小维 毛宁轩 鞠杰 罗玲莉 胡彦杰[1] WAN Xiao-wei;MAO Ning-xuan;JU Jie;LUO Ling-li;HU Yan-jie(School of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学材料科学与工程学院,上海200237

出　　处：《现代化工》2024年第10期88-93,共6页Modern Chemical Industry

基　　金：国家自然科学基金(22378128,22108079,U22B20143,U22A20429);上海市科学技术委员会项目(22dz1205900)。

摘　　要：为了进一步改善气相白炭黑的分散性,利用中试流化床对其进行干法改性。选择高含碳量的聚二甲基硅氧烷(PDMS)为改性剂,考察了预活化、改性温度、时间、气速和改性剂质量分数对气相白炭黑疏水性能的影响。结果表明,最佳工艺条件为:预活化温度为200℃、预活化时间为30 min、用水质量分数为10%、氮气气速为4 Nm^(3)/h、改性温度为300℃、改性剂PDMS质量分数为25%、反应时间为90 min。改性后气相白炭黑含碳量为4.89%,表面羟基量降为0.15个/nm^(2),可润湿率为0%,提高了气相白炭黑的疏水性。此外,探究了改性气相白炭黑对硅橡胶的补强性能,含碳量为2.5%的气相白炭黑补强时,断裂伸长率提高了24.8%,补强系数提高18.0%,拉伸强度提高8.0%,补强效果最佳,有效提升了硅橡胶的综合力学性能。To further improve the dispersibility of fumed silica,a pilot-scale fluidized bed is utilized for its dry modification by using polydimethylsiloxane(PDMS)with a high carbon content as the modifying agent.The influences of pre-activation,modification temperature,time,gas velocity,and the mass fraction of the modifying agent on the hydrophobic properties of fumed silica are studied.Results indicate that the optimal process conditions are as follows:pre-activation temperature is at 200℃,pre-activation time is 30 min,water mass fraction is 10%,nitrogen gas velocity is 4 Nm^(3)·h^(-1),modification temperature is at 300℃,PDMS mass fraction is 25%,and reaction time is 90 min.After modification,carbon content of fumed silica is 4.89%,surface hydroxyl group content declines to 0.15 groups·nm^(-2),and the wettable rate is 0%,which enhances the hydrophobicity of fumed silica.Furthermore,the reinforcing performance of the modified fumed silica on silicone rubber is explored.As fumed silica with a carbon content of 2.5%is used to reinforce,the tensile elongation at break of silicone rubber increases by 24.8%,the reinforcement coefficient increases by 18.0%,and the tensile strength up 8.0%,showing the best reinforcement effect and effectively improving the comprehensive mechanical properties of silicone rubber.

关 键 词：气相白炭黑 PDMS 流化床 干法改性 硅橡胶性能 

分 类 号：TQ127.2[化学工程—无机化工]