Synthesis And Characterization Modified Polyurethane And Nanocomposites Based On Soybean Oil

With the problem of environmental protection and petroleum-based resources exhaustion have been paid increasing attention, the study on preparation environment friendly polymer derived from renewable resources has become the focus of attention. In the present paper, biodegradable and biocompatible soy-based polyol was used as soft segment of polyurethane (PU). Polyurethane acrylates were prepared by acrylation of polyurethane. Hydroxyl-fuctionalized carbon nanotubes (CNT) and surface modified attapulgite (ATT) were used as fillers to prepared PU/CNT and PU/ATT nanocomposites. The structure-property relationships were studied. It has very important theoretical and practical significance to broaden the apply field of polyurethane materials. Moreover, graphite oxide (GO) and graphene were organic modified via radiation-induced graft polymerization to improve the dispersion in polymer matrix.1. Three polyols based on ESO were prepared by oxirane ring opening with methanol, glycol, and1,2-propanediol. Polyurethane acrylates (PUAs) were prepared by the reaction of these polyols with isophorone diisocyanate (IPDI) and hydroxyethylacrylate (HEA) by a thermal polymerization process. The acrylated reaction between PU and HEA could significantly increase the crosslinking density, glass transition temperature, damping properties, thermal stability and mechanical properties of PUs. Furthermore, those properties of PUs and PUAs increased with the increasing of OH number. It should be noted that the PUA248appeared as a rigid plastic with the tensile strength higher than40MPa and the Young's modulus of724MPa. The soy-based PUAs could be employed for green, inexpensive, biodegradable materials in insulating material field.2. Three different diameters of hydroxyl-functionalized CNTs were used to reinforce the soy-based PU matrix. The aim was to find structure-property relationships within neat PU and PU/CNT nanocomposites. The results revealed that the larger diameter CNTs more easily dispersed in the PU matrix than the smaller diameter ones, which easily formed irreversible agglomerates. Covalent functionalizing of CNTs is the most effective method to improve load transfer efficiency. However, our experiment demonstrated that CNT dispersion in the polymer matrix was a more important factor in the production of superior CNT-based nanocomposites. The tensile strength and Young's modulus of PU nanocomposites enhanced with the increase of CNT diameter. As compared with neat PU, with the increase of CNT diameter, the thermal conductivity of PU nanocomposites was improved by77,63and80%, respectively. The glass transition temperature of PU nanocomposites also increased with the increase of CNT diameters. Furthermore, adding small amounts (1wt%) of CNTs to the PU matrix significantly improved its thermal stability.3. The different ATTs were obtained by acid-activated or silane coupling agents (KH560and KH570) modification. Surface treatment of ATTs did not change its crystal structure. The ATT fibers were coated with silane coupling agents after surface modification. Four types of ATT (neat ATT, acid-ATT, KH560-ATT and KH570-ATT) were used to reinforce the soy-based PU matrix. The storage moduli, glass transition temperature, tensile strength and Young's modulus of PUs significantly increased with the increase of ATT contents. The acid-ATT has the best reinforce effect with12wt% acid-ATT loading,16.8℃improvement in glass transition temperature,443%increment in tensile strength,8-fold increase in Young's modulus of PU nanocomposites were obtained. Furthermore, with the incorporation of KH560and KH570modified ATT, the thermal stability of PU nanocomposites was significantly improved with the increase of ATT content.4. Poly(acrylic acid)(PAA), poly(acrylamide)(PAM) and polystyrene (PS) successfully grafted GO via y-ray radiation-induced graft polymerization. The result hybrids were named as GO-g-PAA, GO-g-PAM and GO-g-PS, respectively. The thermal conductivities of GO-g-PAA and GO-g-PAM were0.44and0.75W/m-K, respectively. Moreover, GO-g-PS was reduced by solvothermal method to prepare PS/graphene hybrid. The hybrid has higher than81.3%grafted PS and excellent thermal stability with initial decomposition temperature of381.5℃. It could be used as nanofiller to prepare superior polymer nanocomposites.