Abstract
Birefringent and mechanical properties of epoxide resins are markedly influenced by both curing agents and cure rate, although phthalic acid anhydride is generally recommended to bisphenol type epoxide resins used as photoelastic materials. A systematic study has been undertaken, therefore, to clarify the influence of acid anhydride agents with various molecular structures on the properties of the resins prepared at a constant network chain density.
As the results, the following facts have been obtained. In the rubbery region, some agents displayed higher figure of merit than that of phthalic acid anhydride hitherto employed. The Poisson's ratio of the resins was accurately determined by using an electro-optical device. In the glassy region, the modules of elasticity of the resins decreased unexpectedly while their photoelastic sensitivity increased gradually under the curing process.
Besides, the coefficient of thermal expansion, Charpy impact value and other physical properties of the cured resins were presented as the basic data for photoelastic experiments.
