文献类型：期刊文献

英文题名：Reinforcement Mechanism of Silica Surface Hydroxyl: Janus Effects

作者：Wang, Bohui[1]; Hu, Jinneng[1]; Liu, Kunpeng[1]; Zhang, Ling[1]; Jiang, Haibo[1]; Li, Chunzhong[1]

机构：[1] Shanghai Engineering Research Center of Hierarchical Nanomaterials, Key Laboratory for Ultrafine Materials, Ministry of Education, School of Materials Science and Engineering, East China University of Science & Technology, Shanghai, 200237, China

年份：2022

外文期刊名：SSRN

收录：EI(收录号：20220416197)

语种：英文

外文关键词：Dispersions - Fillers - Molecular dynamics - Reinforcement - Silicone rubber - Tensile strength

摘要：Silica is one of the best reinforcing fillers for silicone rubber due to its similar structure to the main chain of silicone rubber and abundant surface hydroxyl groups. However, for the role of surface hydroxyl groups in reinforcement, there are many conflicting conclusions. This paper combines experiments and molecular dynamics calculations to illustrate that the reinforcing mechanism of the hydroxyl group is two-sided, namely, "Janus Effects". Firstly, at 30 phr, the tensile strength increases as the number of hydroxyl groups decreases, molecular dynamics calculations show that as the number of hydroxyl groups increases, (I) the interaction forces between the silica particles increase, inhibiting their dispersion in the silicone rubber; (II) physical-adsorption water increases and the strength of the rubber-filler interfacial interaction decreases, reducing the reinforcing effect. At 5 phr, the tensile strength and the filler-rubber interfacial interaction of Silica-5 phr are higher than A200-5 phr; molecular dynamics calculations show that the strength of the filler-rubber interfacial interaction increases gradually with increasing hydroxyl groups for similar dispersion states. This paper would help design more desirable silica structures with a highly branched structure and multiple hydroxyl groups as an ideal reinforcing agent. ? 2022, The Authors. All rights reserved.