Network Construction And Shape Memory Performance Of Self-Healing Epoxy Resin With Furan Ring

Self-healing shape memory epoxy polymer (SMEP) is a class of novel "smart" polymer that can repair cracks autogenously, be deformed and fixed in a second, temporary shape and are able to recover their original, permanent shape when they exposed to an appropriate stimuli. However, the traditional epoxy resin cureds are rigid, brittle and without recyclable propertiy, that lead to the excellent shape fixed performance but poor shape recovery property. Hence base on the reasonable designing of epoxy crosslinking network structure, this article discuss the effect of regularity network of SMEP and soft segments component ratio on shape memory properties. At the same time, in order to prolong the service life of materials, the "furan-maleimide" structure was introduced into SMEP network structure. Diels-Alder dynamic reversible reaction would make SMEP have self-healing capability. The main content is as follows:Prepare the heat resisitant shape memory epoxy resin systems. A trifunctional epoxy resin (TFEP) cured by 4,4'-bis-(diaminodiphenyl) methane system (TFEP/DDM system) and bisphenol A epoxy(DGEBA) toughing TFEP/DDM system (TFEP/DGEBA/DDM system) were prepared. The non-isothermal kinetics of these two systems was systematically investigated by DSC. Non-isothermal model-fitting kinetics investigation concluded that the curing process fit in the two-parameter Sestak-Berggren model. DMTA and TGA confirmed that both these two systems kept excellent thermal stabilities. Shape memory tests showed a low angle (12.5°) variable at onset temperature for TFEP/DDM system because of its large crosslinking density and rigidity. And TFEP/DGEBA/DDM system whose shape fixed ratio is almost 100% and shape recovery ratio is 97.2% performed a good shape memory property.Design the self-healing shape memory epoxy resin systems. From the network stiffness and flexibility points of the view, epoxy resin system [DGEBA(x)/DGEBAEO-06] is cured by furfuryl amine (FA) and two type of bismaleimide (BMIDPM and BMIE), then DGEBA(x)/FA/BMIDPM system and DGEBA(x)/FA/BMIE system netwoks (original and recycle samples) are prepared. DGEBA(x)/DGEBAEO-06/FA linear structures are characterized by GPC and FTIR. FTIR, DSC, SEM and dissolved method are used to prove the self-healing properties of all crosslinking network systems. Tensile test showed that increasing the crosslink density and the content of rigid chain segments would strengthen the networks (breaking strength is from 46.47 to 64.54 MPa), but elongation at break decreased (from 4.94% to 3.27%).All the crosslinking network systems have excellent properties in the shape fixing (all above 98%), while as the rigid chain segment content increase, shape recovery rate gradually reduced.Design the neat network structure of shape memory epoxy resin systems. HBGE/FA/BMIE(x) crosslinking networks (original and recycle) are prepared by FA, hexahydrohsphenol-A diglycidyl ether (HBGE) and BMIE. By using FTIR, DSC and dissolved prove tests, self-healing properties of HBGE/FA/BMIE(X) systems are proved. All the HBGE/FA/BMIE(x) crosslinking networks show the brittle fracture in tensile test, and the results indicate crosslink density is proportional to the fracture strength, but is inversely proportional to elongation at break. Shape memory performance test showed that all the crosslinking systems have outstanding performance in the shape fixing (all almost 99%). Shape recovery rate is increaseing as crosslinking density decrease (from 90.72% to 96.70%). And the regularity of neat crosslinking network benefit to recovering the original shape more rapidly.