| The fonnation kinetics of epoxy resins derived from bisphenol-A (BPA), bisphenol-S (BPS), and epichlorohydrin was studied. The reactivity of bisphenol-A with epichlorohydrin is higher than that of bisphenol-S, the rate of dehydrochlorination of chlorohydrin ether in the presence of alkali and water is much higher than that of the condensation of phenolic hydroxyl groups with ECH. The apparent reaction order of phenolic groups with ECH and terminal epoxide group in the oligomer are all second order. The kinetics of the cure reaction for a system of bisphenol-S epoxy resin (BPSER), with curing agents, such as 4,4?diaminodiphenylmethane (DDM) and phthalic anliydride etc., were studied by means of differential scanning calorimetry (DSC). Analysis indicated that an autocatalytic behavior was shown in the first kinetic control stage, and can be well described with the model proposed by Kamal, which includes two rate constants, k1 and k2, and two reaction orders, m and n. The overall order, m , is in the range 2-3. With the proceeding of the cure reaction, the reaction is mainly controlled by diffusion in the lafter stages. The glass transition temperatures (TgS) of the BPSERlhardener samples isothermally cured partially were determined by means of torsional braid analysis (TBA), and the results show that the TgS increase with the increasing of the cure conversion. It also found that the group in BPSER increases Tg values than that of BPAER. The thermal degradation kinetics of this system was investigated by thermogravimetric analysis (TGA). It illustrated that the thermal degradation of the BPSER!hardener has n-order reaction kinetics.
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