Studies on novel binary accelerator system in sulfur vulcanization of natural rubber

Abstract

The synergistic activity of binary accelerator systems in rubber vulcanization is well known. Thiourea and its derivatives are important secondary accelerators in this context. It is suggested that thiourea containing binary systems of rubber vulcanization proceed by a nucleophilic reaction mechanism. Amidinothioureas (ATUs), which are derivatives of thiourea, have been investigated extensively as secondary accelerators. One of the aims of this study was to get further proof with regard to the theory of the nucleophilic reaction mechanism in such binary systems. In the present study phenyl substituted ATU was used as a secondary accelerator along with mercaptobenzothizyl disulfide, tetramethyl thiuram disulfide, or cyclohexyl benzthiazyl sulfenamide in the sulfur vulcanization of natural rubber. The results showed an appreciable reduction in the cure time for the mixes containing the ATU compared to the reference mixes. These results are indicative of a nucleophilic reaction mechanism in the vulcanization reaction under review. These vulcanizates also showed comparatively better tensile properties and good retention of these properties after aging. The optimum dosages of the secondary accelerator required for these vulcanization reactions were also derived. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1–8, 2001

A method to improve the mechanical performance of styrene-butadiene rubber via vulcanization accelerator modified silica

“…Mixed accelerators have been widely applied and known to give superior properties in rubber vulcanization reaction [13]. Thiourea and its derivatives were reported to be effective secondary accelerators with N-Cyclohexyl-2-benzothiazole sulfenamide (CBS) [14].…”

Study on the structure-properties relationship of natural rubber/SiO2 composites modified by a novel multi-functional rubber agent

“…It has been realized that, except for the fine-dispersion of filler in rubber matrix, if the silane coupling agents possess another function of rubber agents, like acceleration function, the properties of rubber composites will be significantly promoted [8]. Moreover, binary accelerator systems are being widely applied in the rubber industry and become increasingly popular based on the fact that such binary systems can effectively facilitate the vulcanization process to be carried out at a lower temperature within a short time [10][11][12]. Among these binary accelerator systems, thiourea (TU) and its derivatives are favorable for improvements in the vulcanization process and mechanical properties of rubber composites [13,14].…”

Facile Synthesis of Thiazole, Thiazine and Isoindole Derivatives via EDA Approach and Conventional Methods

“…Amidinothiourea and its derivatives are important industrial and biological compounds. Recently, amidinothiourea derivatives have been reported to be non-toxic and are used in many pharmaceutical applications [3]. In the field of medicine they are well-known stimulators of intestinal peristalsis and have been used for the clinical treatment of bowel paresis in peritonitis.…”