自乳化硫共聚物的合成及绿色交联胶乳

Sulfur dispersion is the most common crosslinking agent for latex vulcanization. However, sulfur dispersion is unstable and its preparation process is complex, and toxic zinc-containing accelerators should be used together for effective crosslinking. In recent years, synthesizing sulfur copolymers through inverse vulcanization of elemental sulfur and vinyl monomers has received widespread attention. Herein, self-emulsified sulfur copolymers (STD) were prepared by inverse vulcanization of elemental sulfur, polysorbide 80 and 1,3-diisopropylbenzene. The effect of monomer feed ratio on the structure and yield of STD was studied. According to laser particle size distribution analyzer and scanning electron microscope measurements, STD emulsion could be stably dispersed in water for a long time with an average size of about 80 nm. Further, STD was used as the crosslinking agent for carboxylated nitrile rubber latex, and the influences of STD content and composition on the properties of crosslinked rubber were systematically studied. The results showed that the fractions of sulfur and polysorbate 80 in STD determine the properties of crosslinked rubber by affecting crosslinking density and plasticizing effect, respectively. Compared with sulfur dispersion, STD emulsion is more stable with smaller micelle size and has higher reactivity, which avoids using toxic zinc-containing accelerators and imparts the crosslinked networks with better mechanical properties, thus exploring new avenue for the green crosslinking of rubber latex and the preparation of high-performance rubber materials.