Linked from
The 15 pages that link to Cross-link, each with the reason it gives.
Epoxy resinBroader topic: Cross-links give cured epoxy its rigidity and resistance to solvents.
Nitrile rubberRelated: Cross-links help nitrile rubber retain shape and elasticity under use.
Gel (colloid)Related: Cross-links hold many polymer gels together and limit chain motion.
Pendant groupRelated: Reactive pendant groups can form cross-links between neighboring chains.