改性白炭黑/天然橡胶复合材料的制备及性能

采用双-γ-(三乙氧基硅)丙基]四硫化物(Si69)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)、乙基三甲氧基硅烷(11-100)对白炭黑进行表面改性,并制备改性白炭黑/天然橡胶复合材料。利用红外光谱(FT-IR)、热重分析(TG)、扫描电镜、橡胶加工分析仪等测试手段对改性白炭黑及改性SiO_2/NR复合材料的结构与性能进行了表征,并研究其硫化性能及力学性能。结果表明,经FT-IR、TG分析,3种硅烷偶联剂已成功接枝到白炭黑表面;改性SiO_2/NR复合材料相对于未改性SiO_2/NR,焦烧时间变长,正硫化时间缩短,结合胶含量增大;改性SiO_2/NR与未改性SiO_2/NR相比其定伸应力、撕裂强度明显提高,但断裂伸长率有所减小;改性白炭黑在天然橡胶基体中的分散性明显提高,其中Si69-SiO_2在天然橡胶基体中的分散性最好;Si69-SiO_2/NR复合材料的滚动阻力与生热最低;改性后的SiO_2/NR复合材料的拉伸断面粗糙程度增加。

Preparation and Characterization of Modified Silica/Natural Rubber Composite Material

The silica surface was modified with three different silane coupling agents (Si69,KH570,11-100),and modified-SiO2/natural rubber (NR) composite materials were prepared.The structure and property of modified-SiO2 and modified-SiO2/NR composite materials were characterized by FT-IR,TG,SEM,and rubber process analyzer (RPA).The mechanical and sulfuration property of natural rubber composite materials were studied.The results show that three silane coupling agents is successfully grafted onto silica surface and for modified-SiO2/NR compared with unmodified-SiO2/NR,the scorch time becomes longer,the cure time is shortened,bound and the rubber content increases.In addition,the stress at definite elongation and the tear strength distinctly increase,but the elongation at break decreases;at the same time,the dispersion of modified silica in the natural rubber matrix improves significantly,the dispersion of Si69-SiO2 is the best;Si69-SiO2/NR has the lowest rolling resistance and calorigenesis Besides,the roughness of stretching surface of fracture of modified-SiO2/NR composite material increases.