For the purpose of developing a novel vulcanizing agent and selfhealing material

melamineformaldehyde(MF)resinwalled microcapsules containing sulfur were prepared by insitu polymerization. Such parameters as pH value

mass ratio of water to sulfur

molar ratio of formaldehyde to melamine

surfactant concentration and core content

were investigated by analyses of microcapsule morphology

particle size distribution and encapsulation efficiency. The morphology of microcapsules indicated that optimal pH value was 4. The mean diameter of microcapsules decreased with increasing surfactant concentration but changed slightly with core content. High encapsulation efficiency was achieved when mass ratio of water to sulfur was 8∶1

and the molar ratio of formaldehyde to melamine was 2∶1. In curometer test

the microcapsules coating sulfur curing system had longer scorch time and optimum curing time

and the vulcanized nitrile butadiene rubber(NBR)had better mechanical properties compared with those of sulfur vulcanized NBR.