Vulcanization of chlorobutyl rubber. II. A revised cationic mechanism of ZnO/ZnCl2 initiated crosslinking

Characteristics and mechanism of low temperature dehydrochlorination of poly(vinyl chloride) in the presence of zinc(II) oxide

“…This result suggests that the activation energy of cross-linking dehydrochlorination is lowered in the presence of ZnO. Hendrikse et al [25,26] There have been many kinetic studies [1,4,11,22,24] for the dehydrochlorination of pure PVC, and the activation energy of the dehydrochlorination 1 is 109-134 kJ mol -1 .…”

Organo-Chlorinated Thin Films Deposited by Atmospheric Pressure Plasma-Enhanced Chemical Vapor Deposition for Adhesion Enhancement between Rubber and Zinc-Plated Steel Monofilaments

“…According to certain studies, 39,40 these zinc salts can act as catalyzers for chlorinated polymers cross-linking. ZnCl 2 could therefore, locally, assist sulfur as a cross-linking promoter, inside the plasma layer and in the region close to the plasma layer.…”

Vulcanization of chlorobutyl rubber. III. Reaction mechanisms in compounds containing combinations of zinc dimethyldithiocarbamate, tetramethylthiuram disulfide, sulfur, and ZnO

“…HCl initiated reversion was discussed in an earlier report in this series. 25 The reason for the slow increase in crosslink density on prolonged heating as shown in Figure 7 is not known; no more ZnCl 2 is formed at this stage.…”

“…Again, there was a delay between ZnCl 2 formation and crosslinking, indicating that the formation of conjugated diene butyl on dehydrohalogenation is a necessary precursor to crosslinking. 7,25 Treatment of the vulcanizate with methyl iodide 27 showed that the majority of the crosslinks were carbon-carbon (Table I). After 30 min, a crosslink density of 3.3 ϫ 10 Ϫ5 mol/mL was attributable to carbon-carbon crosslinks (62% of total), similar to the carbon-carbon crosslinks formed in the absence of sulfur (3.3 ϫ 10 Ϫ5 mol/ mL).…”