Polymers degradation cross linking

Polymers that cross-link Polymers that degrade... 

Polymers Predominantly Cross-Linking Polymers Predominantly Degrading... 

As it will be discussed In Sect. III.B.2.d), isobutene homopolymer and isoprene-iso-butene copolymer (butyl rubber) are prone to degrade under the attack of free radicals Therefore, these polymers cannot cross-link (unless h comonomer content is present) in the presence of free radicals and usually are not used in grafting reactions since a low degree of graft is observed (Tdrle 9, n 1,2). 

Polymers that Cross-Link Polymers that Degrade... 

The cross-linking reactions have been performed by at least five processes. In Reaction Type 4a, direct cross-linking occurs by covalent bond formation between functionalities on each of the two immiscible polymers without degradation of either polymer. The cross-linking is most often performed by reaction of pendent, nucleophilic sites of one multifunctional polymer with pendent, electrophilic sites of the second multifunctional polymer. Common examples include reactions of pendent acid or amine nucleophiles on one functionalized polymer with pendent electrophihc groups such as epoxide, oxazoline, or ortho ester on a second functionalized polymer. 

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