The morphology and mechanical properties of NBR/ZDMA/nano-CaCO_3 composites

摘要

The nano-calcium carbonate (nano-CaCO_3) is an important nano-material, of which the surface modification and application has been widely studied. The reinforcement action of nano-CaCO_3 in rubber was also widely concerned with, but the synergistic reinforcement effect of nano-CaCO_3 with zinc methacrylate (ZDMA) was barely noticed by the researchers. In this paper, ternary composites of NBR, nano-CaCO_3 and ZDMA were prepared. Three kind of nano-calcium carbonate were used, in which U-CaCO_3 is an unmodified nano-calcium carbonate, CCR is a commercial nano-CaCO_3 treated by stearic acid, and M-CaCO_3 is a new modified nano-CaCO_3 prepared in our laboratory. The synergistic reinforcement effect between nano-calcium carbonate and ZDMA were investigated. In the peroxide curing system, the apparent synergistic reinforcement effect of CCR and ZDMA to NBR was observed. In the multiple curing systems of peroxide and sulfur, M-CaCO_3 and ZDMA appeared obvious synergistic reinforcement to NBR. The application of multiple curing systems improved the extensibility of composites obviously. The acetone extraction experiments indicated that the close combine between M-CaCO_3 and rubber matrix were formed. Scanning electron microscopy (SEM) showed that M-CaCO_3 particles disperse well in the rubber matrix, the mechanical properties of NBR/M-CaCO_3/ZDMA vulcanizates were superior to those of NBR/M-CaCO_3 system. The addition of ZDMA improved the dispersity and combining power of M-CaCO_3 in NBR.