硅烷偶联剂改性水镁石/天然胶乳复合胶膜的性能

摘要

采用硅烷偶联剂y-氨丙基三乙氧基硅烷(KH 550)改性水镁石,然后与天然胶乳(NRL)共混制备了改性水镁石/NRL复合胶膜,研究了改性水镁石的微观形貌、悬浮性能和元素含量,考察了改性水镁石用量对NRL流变性能及其复合胶膜硫化特性、物理机械性能的影响.结果表明,KH 550改性水镁石的表面含有有机亲油基团,能够悬浮于水中,且与未改性水镁石相比,其表面铝、铁、钙元素含量有所减小,碳元素含量增大;随着改性水镁石用量的增加,NRL的黏度和表面张力均增大,NRL复合胶膜的最大转矩与最小转矩均先增大后减小,转矩差值增大,正硫化时间缩短,硫化速率提高,拉伸强度先升高后降低,300％定伸应力与邵尔A硬度均增大,扯断伸长率降低,当改性水镁石用量为3份时,拉伸强度为24.15 MPa,相比纯NRL胶膜提高了16％,且改性水镁石均匀分散在橡胶基体中,与橡胶基体两者界面结合良好.%The brucite was modified by silane coupling agent γ-aminopropyltriethoxysilane (KH 550) and then blended with natural latex (NRL) to prepare modified brucite/NRL composite film.The morphology,suspension properties and element content of modified brucite were studied.The effects of modified brucite on rheological properties of NRL and curing characteristics and mechanical properties of the composite films were investigated.The results showed that the surface of KH 550 modified brucite contained organic lipophilic group and could be suspended in water,aluminum,iron and calcium element content on surface decreased,and carbon content increased compared with those of unmodified brucite.With increasing modified brucite amount,both of the viscosity and surface tension of NRL increased,the maximum torque and the minimum torque increased first and then decreased,and the torque difference increased,the curing time shortened,curing rate increased.And the tensile strength increased first and then decreased,the modulus at 300％ and Shore A hardness increased and the elongation at break decreased.When the amount of modified brucite was 3 phr,the tensile strength was 24.15 MPa,which was 16％ higher than that of the pure NRL film,the modified brucite was evenly dispersed in the rubber matrix,and the interface was well bonded with the rubber matrix.