METHOD TO VULCANIZE NATURAL RUBBER FROM MEDIUM AMMONIA LATEX BY USING GLUTARALDEHYDE

A novel and inexpensive method for vulcanizing natural rubber by using glutaraldehyde was introduced. The vulcanized rubber samples were prepared by adding various amounts of glutaraldehyde to medium ammonia natural rubber latex. Cross-linking reaction occurred only in the presence of ammonium hydroxide in natural rubber latex upon the addition of glutaraldehyde. Cross-linked rubber has been obtained by reacting natural rubber with pentane-1,5-diylidenediamine formed from the reaction between glutaraldehyde and ammonia. The vulcanized materials were characterized by mechanical analysis and thermogravimetry. The results revealed an improvement in mechanical and thermal properties by vulcanization. Activation energy of degradation has been calculated using the Horowitz-Metzger equation. The cross-link density of the vulcanized rubber was determined from swelling experiments in benzene. Fourier transform infrared spectroscopy has been employed to confirm the cross-linking reaction between rubber molecules. From the overall characterizations, natural rubber vulcanized with 12 mL of 10% glutaraldehyde exhibited better properties. [doi:10.5254/rct.12.88920]