Location: Home > News > Industry News

Industry News

THE DIDIFFERENCE BETWEEN EFFICIENT VULCANIZATION (EV) AND SEMI-EFFICIENT VULCANIZATION (SEMI-EV) CONDITIONS IN LATEX.
Editor:XUAN ZOU  Post Time:2012-06-16  Click:

This article mainly analyze vulcanization conditions in latex.

Efficient vulcanization (EV) and semi-efficient vulcanization (semi-EV) systems are characterized by having a high accelerator concentration and a low sulphur concentration.

There are differences between the vulcanization of latex systems and dry rubber, not least the fact that the vulcanizing ingredients (sulphur, accelerator, zinc oxide) have to migrate from their solid phase, through the aqueous phase to the rubber phase. In addition the aqueous phase contains ammonia and other materials such as proteins which can aid the vulcanization.

In dry rubber, these conditions lead to a network having a high proportion of crosslinks containing only one (mono-sulphidic) or two (di-sulphidic) sulphur atoms (eg. crosslinking agent BIPB). Networks of this type have a much better aging resistance than those where the crosslinks contain a greater number of sulphur atoms (polysulphidic crosslinks).

However, the conditions required to create this type of network require high vulcanizing temperature, whereas latex articles are usually vulcanized at much lower temperatures – latex article tend to be thin, and have a high surface to volume ration, and are thus more prone to oxidation at high temperatures.

As a consequence dipped latex articles will have a network structure which is predominantly polysulphidic. This type of network will give good physical properties, but the aging resistance will be less than for an EV or semi EV system.

 

Hunan Yixiang Chem. manufacture crosslinking agent BIPB,TAIC for CPE/EPDM CABLE etc. Welcome your calling.contact: JackTan ,tel,+86 731 83282288,cell:+8613786182074,QQ:,旺旺:,Mail:sales@hnyxchem.com.cn

 


[Back]  [Home]