红外光谱法研究XeF2表面氟化丁腈橡胶动力学

丁腈橡胶表面氟化可以在橡胶表面生成类似氟橡胶结构的保护膜,在保留基体高弹性、耐寒性等优良性能的基础上,可以使丁腈橡胶的抗摩擦、耐介质和抗老化性能得到增强,使用范围增大.用红外光谱法进行了丁腈橡胶氟化反应动力学探索,得到了实验反应速率方程,丁腈橡胶表面氟化反应表观上为1.5级反应.由于反应生成的氟化层对后续反应的影响,实验反应级数存在随氟化时间增加而减小的趋势,速率常数则随着反应温度升高而减小.

A Preliminary Study on Surface Fluorination Reaction Kinetics of NBR with XeF2

The surface of butadiene-acrylonitrile rubber(NBR) can be modified by fluorination reaction to form a film with a similar structure as fluororubber,which helps to improve the agent and aging resistance of NBR while keeping the bulk's good elasticity and cold durability.In this paper,NBR was modified by fluorinating with XeF2 and the reaction kinetics of fluorination was studied by FT-IR spectrometry.The apparent reaction order of 1.5 was suggested,which seemed to become less for long reaction time.However,the surface fluorination is different from the common kinetics in that the rate constant was smaller at higher temperature.This may be attributed to the effect of the fluorinated film on the diffusion of reactants,and the differences in the structure of the fluorinated film at different reaction temperature.