A New Hydrogenated Butadiene-Acrylonitril-Butylacrylate Rubber and Its Properties

A new kind of ternary copolymer rubber (BNBR) was synthesized by butadiene, acrylonitrile and butylacrylate. Due to - CN, - COOR,- CH = CH- groups in the molecular structure,  the ternary copolymer rubber exhibited the excellent properties of NBR and ACM. However, the degradation of the material properties, such as the thermal stability and the ozone resistance, was induced because of -C = C – bonds in the ternary copolymer rubber. As we known, hydrogenation is an important method to improve the properties of unsaturated elastomers so that saturated elastomers with greater stability against thermal and ozone degradation can be obtained.

In this paper, a new kind of the ternary copolymeric rubber (BNBR) was carried out hydrogenation by homogenous rhodium compound RhCl(PPh₃)₃ in chlorobenzene as catalyst. The degree of hydrogenation was evaluated by proton nuclear magnetic resonance spectroscop (¹HNMR) technique and FTIR spectroscopic technique. The effect of catalyst concentration, reaction time, hydrogen pressure on the conversion and product selectivity was discussed. The result shows that hydrogenation degree of product (HBNBR) can be extended to 98%. The thermal stability behavior and the ozone resistance of hydrogenated ternary copolymers rubber (HBNBR) was investigated by thermogravimetric analyses (TGA) and by CCD camera, respectively. The results exhibited that hydrogenated ternary copolymer rubber (HBNBR) showed excellent thermal stability behavior and the ozone resistance properties comparing to ternary copolymer rubber (BNBR).

 Keywords: Ternary copolymer rubber (BNBR) Homogeneous hydrogenation; Rhodium catalyst; Thermal stability; Ozone resistance