Mechanism Analysis of Rubber Surface Stickiness

The nature of rubber vulcanisation is the process of linear molecular chains forming a three-dimensional network structure through cross-linking reactions. The direct manifestation of surface sticking is that the insufficiently cross-linked molecular chains remain on the surface of the product, or abnormal adhesion occurs at the interface with the mould.
The core mechanisms include
Insufficient cross-linking density: the vulcanisation reaction is incomplete, resulting in too many free ends of the molecular chains on the surface.
Interfacial chemisorption: low molecular weight substances in the formulation (e.g. plasticisers, unreacted vulcanising agents) migrate to the surface and form a sticky layer.
Physical adhesion:Mechanical occlusion due to mould surface roughness or release agent failure.