Study On Preparation And Performance Of Amine/Epoxy Shape Memory Resin Toughening System

The competition between countries for the space resource has become fierceincreasingly accompanied by the development of technology. Deployable spacestructures can be folded effectively on the earth and expand in-orbit which willreduce launch cost and improve emission efficiency. Therefore, it has gained greatattention home and abroad. So far, the material which can be used as deployablespace structures is mainly epoxy-based shape memory composite. However, thebrittleness and easy creaking of epoxy resin restrict its application, so toughening isan urgent need. This paper studies the toughing of the epoxy resin through addingthe different mixed curing agent which consists of the flexible primary amine curingagent and m-xylylenediamine.The mixtures of dodecylamine curing agent and m-xylylenediamine with fivedifferent ratios are chosen as the toughener for the epoxy resin. The toughenedepoxy resin is characterized by IR, DSC, DMA and its shape memory properties andmechanical properties has also been tested for studying the variation of its phasemicrostructure and macroscopic properties. The results showed that with thedecrease in the content of dodecylamine and the increase of m-xylylenediaminecontent, the glass transition temperature increased, between33℃to100℃and thatthe crosslinking density increased from1.14×10-4mol/cm-3to3.50×10-4mol/cm-3andthat elongation at break reduced from21.36%to5.72%. Shape memory propertiestests showed that with decrease of dodecylamine content, shape fixed ratio of fivesystems increaseed, but the recovery ratio did not change significantly, reachingmore than98%. In addition to EP-100MXDA system, the loop fold number of otherfour EP-DA/MXDA systems could reach25times, which indicated the tougheningeffect of flexible curing agent is obvious. Meanwhile, EP-50DA/50MXDA andEP-25DA/75MXDA are two better toughening systems.The mixtures of octylamine(OA), hexadecylamine(HA) curing agent of thedifferent length of and m-xylylenediamine according to the two different ratios of50PA/50MXDA and25PA/75MXDA are chosen as the toughener for the epoxy resin.The results showed that the two different ratios of EP-OA/MXDA andEP-HA/MXDA toughened systems had played a good toughening effect, and hadgood shape memory properties and mechanical strength, where the tougheningeffect of EP-50OA/50MXDA and EP-50HA/50MXDA systems is more excellentand elongation at braeak are8.33%and15.01%, compared with the EP-100MXDAsystem increased respectively by45%and160%. Compared the relative performance of the different chain length of EP-50PA/50MXDA toughened system,the results showed that the chain length of the flexible curing agent had greatinfluence on the glass transition temperature, the shape recovery rate and themechanical properties, but it had little influence on shape fixed ratio and recoveryratio.