含烯丙基环氧树脂/硫体系的固化特性研究

文中首次报导了含烯丙基双酚A型环氧树脂(DADGEBA)在硫磺作用下的固化行为。通过凝胶化时间,DSC,FTIR的测定,对该体系的固化特性进行了研究,提出了硫磺与环氧树脂DADGEBA的反应机理。该体系可在高温下固化,有两个明显的放热峰;固化反应的机理可能为硫磺在高温下八元环首先发生均裂从而产生链自由基,然后硫磺自由基一方面与烯丙基双键作用进行自由基加成反应;另一方面烯丙基中α位的活泼氢向硫磺链自由基发生转移,从而产生巯基,然后巯基与环氧基团发生开环反应。最终,通过上述两种反应使整个体系交联固化。

Curing reaction of DADGEBA with sulfur

The reaction between DADGEBA (Diglycidyl ether of O,O′-diallyl-bisphenol A) and S(Sulfur) at an elevated temperature was studied by measuring the gelling time, DSC curve and IR spectra. The possible reaction mechanism of the DADGEBA/S system was proposed based on the structure of the cured polymer and the property of sulfur. The results showed that the DADGEBA/S system had a higher reaction temperature. The curing mechanism was likely to be that the sulfur firstly broke its chain when heated to a relatively high temperature and sulfur radical was induced in the system.Then on the one hand the sulfur chain a radical resulted in a radical polymerization reaction with the double bond in the allyl group.On the other hand the α-hydrogen in allyal group transfered to the sulfur chain radical and gave birth to —S—H group, then —S—H group reacted with epoxy group.