甲基丙烯酸改性丁苯橡胶/埃洛石纳米管复合材料的研究

Study of styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by methacrylic acid

采用一种新型非石油资源橡胶补强剂—埃洛石纳米管(Halloysite Nanotubes,HNTs)对丁苯橡胶进行补强,采用甲基丙烯酸(Methacrylic Acid,MAC)为改性剂进一步改善硫化胶的性能,并研究了MAC用量对混炼胶的硫化特性、硫化胶力学性能和交联密度的影响.结果表明,甲基丙烯酸的加入对焦烧时间的影响不大,会降低硫化初期最低扭矩(ML),有利于提高SBR/HNTs的加工性能;MAC的加入可进一步有效改善HNTs的补强效果;当MAC用量大于5phr时,所制备的SBR/HNTs复合材料变为半透明状,说明HNTs在SBR橡胶基体中的分散效果很好;当HNTs和MAC用量分别为40 phr和12phr时,复合材料的综合性能最优,其300%定伸应力、拉伸强度和撕裂强度分别可达6.3 MPa,15.1MPa和51.3 kN/m,同时断裂伸长率可达700%;MAC的加入可以有效提高总交联密度和离子交联密度,对离子交联密度的影响更为显著.

Abstract： A new kind of rubber reinforcing agent from non-petroleum resource, halloysite nanotubes （HNTs） were adopted to reinforce styrene-butadiene rubber （SBR） in this paper. Methacrylic acid （MAC） was employed as interfacial modifier to improve the comprehensive properties of the vulcanizates. The effects of MAC loading on vulcanization characteristics of SBR/HNTs compounds, mechanical properties of vulcanizates and crosslink density （based on Flory-Rehner equation） were investigated. The results showed that HNTs could increase the tensile strength and modulus of SBR vulcanizates. The scorch time of the compounds was basically independent of the MAC content although the torsion of the compounds be- fore scorch was decreased with MAC content. SBR/HNTs compounds incorporated with MAC showed greatly increased tensile strength and modulus. When the MAC loading was higher than 5 phr, translucent samples were surprisingly obtained, indicating uniform dispersion of halloysite nanotubes in the rubber matrix. When the contents of HNTs and MAC were 40 phr and 12 phr respectively, 300% stress, tensile strength and tear strength of the vulcanite reached 6.3 MPa, 15.1 MPa and 51.3 kN/m respectively, with elongation at break up to 700%. The crosslink densities calculated from Flory-Rehner equation indicated that the total crosslink density and the ionic crosslink density of the vulcanizates were increased while the effect on the ionic crosslink density was more obvious.