Improving bonding between elastomer and filler in vulcanisate - by free radical vulcanising pref. in presence of thiuram sulphide accelerator

摘要

Bonding between an elastomer and metals and white fillers in a vulcanisate is improved by carrying out free radical vulcanisation pref. using as accelerator, a thiuram sulphide and pref. in the absence of ZnO and stearic acid. Pref. accelerator is tetramethylthiuram disulphide and the white filler is a synthetic amorphous silica. Pref. elastomer is SBR. In an example, two vulcanisates were formed comprising (a) 100 pts. SBR 1509 (RTM), 20 pts. silica, 2.5 pts. sulphur and 3.8 pts. tetramethylthiuram disulphide, and (b) 100 &ts. SBR 1509, 20 pts. silica and 2.5 pts. sulphur. On swelling in benzene and testing adhesion between the silica and elastomer according to the method developed by G. Kraus J. Appl. polym. Sci. 7. 861-871 (1963), good adhesion was shown for (a) and poor adhesion for (b).