Introduction crosslinks between linear polymer chains, forming flexible three dimensional rubber network. Process of converting a relatively weak and plastic polymer into higher elastic material of considerable strength.
1. Mixing of vulcanizing ingredients.
Sulphur + accelerators + activators or sulphur donor + activators.
2. Active sulphurating agents.
Active sulphurating agents + Rubber hdrocarbon ( R-H)
Rubber – bound intermediate R-Sy-X
Initial polysulphidic crosslinks R-Sx-R
3. Network maturing reactions:-
a) Crosslink shortening with additional crosslinking
b) Crosslink destruction with main chain modification
c) S-S bond interchange
4. Final vulcanization
