Pvc Chemical Cross-linking Modification

3 different crosslinking systems (A): triethanol amine/dicumyl peroxide (DCP)/styrene; (B): cyanurtriamide/dicumyl peroxide (DCP)/styrene; (C): cyanurtriamide are studied in this paper for the chemical crosslinking modification of Poly(vinyl chloride). In the three systems, system (A) realizes the crosslinking of PVC bases on the peroxide crosslinking mechanism, the tensile strength of crosslinked PVC has been improved somewhat, the IR spectrum of gel demonstrates that there are characteristic absorption peaks of n-alcohol that belongs to ethanol amine and benzenoid group. From the analysis of gel structure , deduces that the mechanism of crosslinking reaction: under the initiations of peroxide and high temperature, PVC yields macromolecules free radicals, at the same time , styrene's polymerization and grafting onto PVC takes place, at last the system forms crosslinking structure through coupling between radicals; confirms that triethanol amine can absorb HC1 produced by degradation of PVC, so improves the crosslinking efficiency of peroxide, decreases the HCl's promotion for PVC's degradation; deduces that triethanol amine can activate the PVC macromolecules and prolong the free radicals' life-time of PVC macromolecules; the effect to the PVC macromolecule makes styrene's graft reaction easy, and thus improves the crosslinking efficiency. System (B) doesn't realize the crosslinking of PVC, and system(C) doesn't realize the crosslinking either bases on the multiamine crosslinking mechanism of PVC. The reasons for the two systems cann't form crosslinking structure probably because that cyanurtriamide cann't react with PVC, cann't make the molecules of PVC change to improve the graft reaction of styrene either, so they cann't realize the crosslinking of PVC.