Based on the thermally reversible Diels-Alder reaction between the cyclopentadiene and dicyclopentadiene

the dicyclopentadienyl dicarboxiate derivatives were synthesized by usual organic reaction

and it was taken into PVC molecular chain as a covalent crosslinking agent.The effects of crosslinking agent

catalyst and activator on the crosslinking rate

mechanical properties and the flow feacture of crosslinekd PVC were also investigated in detail.It has been found that when PVC was reacted with crosslinking agent in the melt directly

the crosslinking rate was low(crosslinking reaction taking place at 190℃ for 36min

the gel content of the system was only 26.3%)

when the ammonium salt as catalyst and polyglycol as activator were added into the reactio system at a optimum ratio

the crosslinking rate can raise 7～9 times.The crosslinked PVC not only has good thermally conversion behavior through the analysis of reaction solubility

DSC and flow curves

but also exhibits flow behavior similar to uncrosslinked PVC.Based on the recipe of soft PVC

thermally teversible covalent crosslinked PVC with better mechanical properties in comparison with the original one was prepased.