Polyalkenes crosslinking

This paper covers the knowledge of different procedures of polyalkene crosslinking. Besides the cross-linking, the effect of crosslink formation on the properties of polyolefins which may be of use in various apidications have been dealt with. 

Although much is already known in this field, the possibilities of its exploitation has not been fully explored yet. As an example, the idea of the recombination and disproportionation of low molecular alkyl radicals as an explanation of the crosslinking efficiency of polyolefins may be put forward. Of equal importance is to defme the problems which await a more detailed study as well as to interpret sometimes controversial results and particularly to elaborate new principles of physical crosslinking of polyalkenes or chemically induced crosslinking of oriented macromolecules. 

Reactive admixture for free radical induced cro linking include pcdyfunctimial monomers for an increase in the crosslinking eflidency of polyalkenes, trimethyl propane trimethacrylate, pentaerythritol tetraallyl ether, pentaerythritol trtramdh-acrylate, triallyl cyanurate [24,25] etc. are used. An optimum concentraticn of polyfunctional monomer depends on various fat ors and for a certain cro inkable system can only be found empirically. 

Polyfunctional monomers have been put to use in the crosslinking rf polypropylene and of branched polyalkenes where polymer radicals decay in disproportionatum reaction or fragmentate preferentially. 

For the functionalization of polyalkenes with cycle forming structural units, other more complicated ways of catenane linking of macromolecules can be devised and it is only a question of time which of them will be used in the crosslinking of polymers. 

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