Crosslinking molecular structure alteration

Apart from the effect on the crosslinking efficiency, the use of co-agents in peroxidecuring also imparts the molecular structure of crosslinks. It has been reported that coagents with two or more unsaturated moieties can be incorporated as individual molecules between two elastomer strands to form crosslinks [103-109]. In this way the crosslink structure of peroxide-cured elastomers can be altered. Thus, apart from the expected benefits, such as improved crosslinking efficiency, decreased compound viscosity and faster cure, the use of co-agents may also provide a tool for manipulating mechanical properties. 

The chemical structure of the epoxy matrix constituent as well as processing are reported to strongly influence 11 -I3> the thermoset network and hence the properties and durability of the crosslinked polymer 11 ,4-16). The cure of a reactive prepolymer involves the transformation of low-molecular-weight reactive substances from liquid to rubber and solid states as a result of the formation of a polymeric network by chemical reaction of some groups in the system. Gelation and vitrification are the two macroscopic phenomena encountered during this process which strongly alter the viscoelastic behavior of the material. 

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