Study On The Two-Stage Curing Technology Of A New Shape Memory Epoxy Resin

Deployable structures technology has the advantages of decreasing volume of space transportation, making the construction of large space structures easier and reducing the launch costs etc. Shape memory composites are ideal materials for deployable structures for their ability of large recoverable strain, good shape retention, repeatable memory effects etc.. We prepare a kind of epoxy resin based material which has the property of shape memory and study its shape memory properties and mechanical properties; investigate toughening modification and regelation of epoxy resin based shape memory polymers; make shape memory composite materials with mechanical strength material aramid fiber.We test the curing peak temperature of shape memory epoxy resin system using DSC. One more exothermic peak is found in epoxy resin system with curing agent and the two peaks deviate is more than 100℃, which conforms to demand of two-stage curing technique. Making use of FT-IR, we analyze the curing degree of different epoxy resin systems. We find that the calculation results have some deviation from theoretical value; the conversion rate of epoxy group of systems which is not added curing agent into and that is added into but having no curing reaction have little difference; both are less than theoretical value, but the conversion rate of the system added curing agent and having curing reaction happened is apparently high. Appealing to DMA, we find the glass transition temperature and storage modulus of shape memory epoxy resin system; take unfold experiment above glass transition temperature and find out the systems which have the property of shape memory. By shape memory properties test and mechanical research, we find that the shape memory properties of the system decrease slightly after adding curing agent, but mechanical properties increasing. After mixing shape memory epoxy resin system with aramid fiber, we get enhanced shape memory composite materials. The shape memory properties of the composite material decrease with the increase of the layer number of the fiber. We investigate the fold curved shape of shape memory composite materials, establish bending model and estimate the relationship of bend radius and bending wavelength of the fiber in shape memory composite materials..