ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The crosslinking efficiency of sulfur in the vulcanization of natural rubber in the presence of 2-mercaptobenzothiazole, zinc oxide, and lauric acid has been determined as a function of cure time, cure temperature, and lauric acid concentration. With a low concentration of lauric acid structurally complex networks are formed, which contain 11-19 combined sulfur atoms per chemical crosslink present. The complexity increases with time of vulcanization. With a high lauric acid concentration much simpler networks are formed, which become progressively more simple as reaction proceeds (6 network-combined sulfur atoms per chemical crosslink, decreasing to 2.4 with time). Increasing the cure temperature from 100 to 140°C. reduces the efficiency of crosslinking in both cases. The changes in efficiency are attributed to the influences of the reaction variables (in particular, the concentration of rubber-soluble complexes of the zinc laurate with zinc benzothiazolyl mercaptide) on the structure and subsequent reactions of initially formed polysulfidic crosslinks.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1967.070111112
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