The Synthesis And Curing Behavior Of Bisphenol-F Thiirane/Epoxy Resin System

The structure of thiirane resins is similar to that of epoxy resins. In addition to several advantages that epoxy resins share, thiirane resins have a fast curing speed at low temperature, good adhesion to metals and a high index of refraction, due to their special structure. Therefore, thiirane resins are applied to low-temperature fast curing, substrate adhesion and optical resin materials. The study of bisphenol-F thiirane/epoxy resin will be promising in practical applications.During the experiment, the bisphenol-F thiirane/epoxy resin with low viscosity was prepared to avoid the lack of fluidity in the resins system. Amines and acid anhydrides, as two different types of curing agents, were added to the resin respectively, both of which were studied in detail. The main work in this dissertation is shown below:First, bisphenol F thiirane/epoxy resin was fabricated, based on the raw materials of bisphenol F epoxy resin and potassium thiocyanate. The structure of product was quantitatively analyzed by means of FTIR,1H NMR and EA. The results showed that the epoxy conversion was67%. Second, thiirane resin has greater ring stress than epoxy resin, which makes the former more actively inclined to ring-opening reaction. For15%and50%bisphenol-F thiirane/epoxy resin-anhydride systems, the non-isothermal DSC method was used to study the dynamics, and the Malek method was used to analyze mechanism function, the Kissinger method and advanced iso-conversional method were adopted to obtain active energy, dynamic parameters and equations of the systems. The results showed that the two systems are in line with SB (m, n) model. The mechanical analysis demonstrated that the tensile strength and breaking elongation of the systems varied little as the content of thiirane resin increased. Besides, both systems showed a better adhesion to Cu and a worse adhesion to Al.After ring-opening, epoxy group and episulfide group turned into hydroxyl and sulfenyl, respectively. They had different activities, which could have influences on curing cross-linking networks. We carried some tests on cured resin, using the bisphenol-F thiirane/epoxy resin which thiirane’s content was15%and50%, with different with different stoichiometric ratio of amine and acid anhydride curing agent.The DSC and DMTA results showed that the glass transition temperatures and modules of four system were increased with curing agent amount reducing, which demonstrated that the existence of-SH or-S had great impacts on resin system. The resin curing systems are liable to form a dense cross-link network with high thiirane’s content and thus high curing reaction velocity...