Preparation Of Thermo-electro Dual-responsive Composites Of Shape Memory Polyurethane And Their Properties

Recent years, shape memory polyurethane（SMPU）materials draw more and moreattention. Compared with shape memory alloy, it has advantages including a lower density, alarger deformation and a smaller cost, which make it accessible for many potentialapplication domains. However, unmodified shape memory polyurethane has a poormechanical property and a single respond condition of shape recovery with imposerestrictions on its application range. Preparation of shape memory polyurethane compositematerial is a feasible way to improve its mechanical property and respond condition, and thushas important research significance and application value. Nano-carbon black is a commonadditive of composite material, is able to improve the mechanical properties as well asenhance the conductivity of the material substantially.4’-(2,3-epoxypropoxy) phenyl-4-(2,3-epoxypropoxy)benzoate (PHBHQ), a lowmolecular epoxy resin with the properties of thermotropic liquid crystal, will be added toimprove the mechanical property and change the microstructure and the surface appearanceof the material.A series of shape memory polyurethane, of which a kind is used as matrix to prepare thecomposite material of nano-carbon black and PHBHQ are prepared. The analytic works areas follows:1. High-molecular-weight poly(butylene adipate) glycol is synthesized using adipic acidand1,4-butanediol as raw materials and ZnAc as catalyst. Then it is used as soft segmentwith2,4-toluene diisocyanate and1,4-butanediol as hard segment to synthesize a series ofshape memory polyurethane. The influence of temperature, molar ratio of reactants, reactiontime, etc, on properties of the product is studied. The product is characterized with FTIR,static mechanical test, DMA and DSC. The molecular weight of poly(butylene adipate) glycolis4572. The tensile strength of the shape memory polyurethane selected is11.9MPa. 2. P-hydroxy benzoic acid hydroquinone ester is synthesized using p-hydroxybenzoicacid and NaOH as raw materials, and concentrated sulfuric acid and boric acid as catalyst.The influence of temperature, reaction time and reaction condition on the product is studied.The product is characterized with FTIR. Then the product and epoxy chloropropane are usedas raw material to synthesize PHBHQ. The influence of temperature, reaction time and alkaliaddition on the product is studied. The product is characterized by FTIR, TGA and DSC.3. The shape memory polyurethane composites are prepared using nano-carbon blackand PHBHQ as additives. The influence of content of additive and the method of thermaltreatment on the shape memory property, mechanical property and electro-responsiveproperty of the composite material are studied. The composite is characterized by SEM, staticmechanical test, DMA, DSC, conductivity test and shape memory effect test. The ultimatetensile strength of the composite material of nano-carbon and shape memory polyurethane is34.5MPa, and of the composite material of PHBHQ and shape memory polyurethane is25.9MPa. Both have thermo-responsive and electro-responsive property.