The effect of softener on vulcanization

Softeners used to improve the plasticity of unvulcanized adhesives have different chemical properties.

The effects of the following initiators have been studied: naphthalene oil (crude from rosin and prophyl), forest oil (crude from aromatic compounds), polydiwei (unsaturated) and heavy oil (mainly composed of oil oligocenes and resins).

The effect of softener on vulcanization

The softening effect of styrene-butadiene rubber compound was studied. The formula was as follows :CKC-30A-100, sulfur -- 2, stearic acid -- 2, sulfohinamine 6T-2, zinc grade --5, mineral rubber --5, carbon black --50 and softener --50. The compound was prepared by an open refining mechanism in a solid chamber, and was vulcanized at 1430C.

If a mixture of softener (100 parts by weight) sulfur (2 parts by weight) and accelerator ST(2 parts by weight) is heated at 143 "for 50 minutes (i.e. under curing conditions), the softener and sulfur are added. The maximum amount of sulfur is added with unsaturated and aromatic softeners. As expected, petroleum jelly, which is saturated, does not combine with sulfur.

The sulfur addition kinetics is obviously consistent with the addition of sulfur and softener. Aromatic and resinous initiators (oil and crude petroleum yayqing) can slightly accelerate the addition of sulfur in the initial stage of sulfurization, while chitosan oil can block the addition of sulfur and lead to a phenomenon similar to the initiation of sulfurization.

In spite of their effect on the rate of addition to vulcanization, all the initiators greatly reduced the plasticity. A saturated softener (petroleum jelly) makes the compound less resistant to early vulcanization. The active softener can improve the early vulcanization resistance of the compound.