Polish version

Login form

register


Print

V. Ducháćek, R. Frenkel


The use of quantum chemistry methods in the research of rubber vulcanization mechanism


Polimery 1991, No 2, 63


DOI: dx.doi.org/10.14314/polimery.1991.063

Summary

A vast majority of accelerators used to assist the sulfur vulcanization of unsaturated rubbers is normally used in conjunction with zinc oxide and carboxylic acid. In the literature the formation of a complex composed of the above-mentioned components is postulated, but there is no direct proof of its existence. Therefore, a quantum chemical bond nature and the character of the electron density distribution has ben carried out. The results obtained on the basis of molecular orbitals calculations have been used to compare the efficiency of magnesium, zinc, and cadmium as vulcanization activators. These calculations confirm the experimental results that zinc only from amog these metals is an efficient activator. Zinc-containing complexes are sufficiently stable; however, the zinc-sulfur bonds are unstable. The fact that cadmium oxide is inactive in the process of vulcanization accelerated by thiuram disulfide and it is an active compound in the vulcanization accelerated by mercaptobenzothiazole, has also been explained.


If you are interested in full versions of articles, please contact the editorial team of polimery@ichp.pl