Optimization study of ammonia and glutaraldehyde contents on vulcanization of natural rubber latex

This manuscript presents a continuation work on a simple system to vulcanize natural rubber using glutaraldehyde as a cross-linking agent. Natural rubber latex consists of protein which is allergenic to human body. The protein immobilization behavior of glutaraldehyde is of greatest interest to conduct this study. A study to determine the optimum condition for the vulcanization of the newly introduced system was carried out using glutaraldehyde as a cross-linking agent. Efforts were made to find out the best combination of glutaraldehyde and ammonia to vulcanize natural rubber latex with superior physical properties. Direct vulcanization method was employed to prepare natural rubber vulcanizates from natural rubber latex. The mechanical performance of the vulcanized natural rubber was determined for various combinations of ammonia and glutaraldehyde. Superior tensile properties were observed for the vulcanized rubber prepared from a very high ammonia natural rubber latex. The activation energy of the degradation of the vulcanizates was determined from thermogravimetric analysis. The cross-link density of the vulcanized rubber was determined from swelling experiments in toluene. The very high ammonia natural rubber latex (0.9 wt% ammonia) with 15 mL of 10 wt% glutaraldehyde solution was found to be the effective combination to vulcanize natural rubber latex with excellent properties. Advantage of this technique is the possibility of directly vulcanizing natural rubber latex at low temperature.