engleski

The Mechanism of Triallylcyanurate as a Coagent in EPDM Vulcanizate

The reaction mechanism for EPDM peroxide vulcanization in the presence of triallylcyanurate, TAC as a coagent was studied by IR spectroscopy and equilibrium swelling technique. Coagent TAC is added in EPDM polymer to prevent the scission of polymer chains during the curing process. Because of his incompatibility with polymer TAC was supposed to reside in small domains. Some authors similar to the results obtained in this paper proved the opposite behavior of TAC in the network. To establish the existance of coagent bridges the cleavage of ether linkages in the vulcanizates was made. After that treatment the disappearance of TAC aromatic absorbance in IR spectra was proved and this was confirmation of presence of such bonds. The swelling results indicate that a small part of TAC is incorporated in polymer network as a crosslinks junction. The same conclusion can be evaluated from the presence of allyl groups (930 cm^-1) and their disappearance while the cyclization tekes place.

coagent; EPDM vulcanizate; peroxide vulcanization; IR-scectra

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