Synthesis And Properties Of Epoxy Soybean Oil Based Polymer

In recent years, the "green" of polymer materials has been used widely during polymermaterials due to environmental and energy crisis, and it was found that the development of newmaterials prepared by renewable resources can solve the problem of limited resources andenvironmental pollution. As a kind of chemical raw material, epoxy vegetable oil cancrosslinking cured with curing agent as normal epoxy resin, such as the use ofanhydride-tertiary amine. However, the curing reaction rate was slower than normal epoxy resinand the resulting polymer had poor mechanical properties. According to the above problems,the phthalic anhydride (PA) was selected as the curing agent and N, N-dimethylbenzyl amine(BDMA) as the catalyst. By Fourier infrared (FTIR), thermal dynamic mechanical analyzer(DMA), and thermogravimetric analyzer (TG) and universal mechanical testing machine, thecuring mechanism of curing kinetics, mechanical and thermal properties of epoxy soybean oilbased polymer were studied. Based on this, the synthesis process was further optimized forimproving the performance of polymer.I midazoles catalyst instead of BDMA was chosen ascatalysts for its stronger activity,and six hydrogen of benzene anhydride (HHPA) instead of PAwas chosen as cured agent for its low melting point.For comparsion, the bisphenol A typeepoxy resin E44modified epoxy soybean oil polymer was prepared to improve the thermal andmechanical properties of the polymer. Through comparing the performance of polymer withdifferent E44content, the best formula was found. In addition, the biodegradability of epoxysoybean oil based polymer was preliminarily investigated by natural soil burying methodthrough the analysis of the group changes, the thermal decomposition of quality change andsurface morphology by FTIR, TG and scanning electron microscope (SEM).(1)The curing mechanism of the curing system of PA-BDMA cure epoxy soybean oil isthat BDMA prompted PA ring opening form zwitterionic first, then with the epoxy group ofESO chain reaction to generate alkoxide intermediates, alkoxide intermediates and then reactswith another PA generate carboxylic acid anions, the reaction generate polyester crosslinkednetwork structure was circled. By analysis of the spetra of FTIR, it is found that the generationof the reactive intermediates to promote the system of polymer reaction, and therefore theamount of the catalyst and curing agent has great effect on the reaction rate and reaction degreeof the curing reaction, with the increase of dosage of catalyst and curing agent, reactiondegree,the reaction rate,crosslink density,the glass transition temperature,thermal stability,tensile strength increased.(2) The epoxy soybean oil based polymer used by1-methylimidazole-PA curing epoxysoybean oil, instead of BDMA, have shorter curing time, higher polymer crosslinking density,better thermal stability, tensile strength can reach7.13MPa. And the epoxy soybean oil basedpolymer used by1-methyl imidazole-HHPA （instead of PA）curing epoxy soybean oil can make gel-temperature reduced, and make the polymer density, thermal stability, tensile strengthdecreased, for instance, tensile strength can only be reached6.35MPa.(3)The interpenetrating polymer network structure formed by epoxy soybean oil basedpolymer with part epoxy resin instead of the epoxy soybean oil had the better compatibilitysystem, and they had hardly been separated,.At the same time, they had higher thermal andmechanical properties.When epoxy resin content was60%, the comprehensive performance ofpolymer is the best, the crosslinking density of polymer is0.79×10-3mol/cm3, maximumdecomposition temperature is420.6℃, the tensile strength was49.98MPa, the impact strengthwas17.95KJ/m2.(4)The contact Angle of epoxy soybean oil based polymer of1-methylimidazole-HHPAsystem and1-methylimidazole-PA system were equally greater than90°, which indicated thatthe polymer had better hydrophobic. Among the preparation of polymer from1-methylimidazole-HHPA system had better hydrophobicity. Relatively, the contact Angle ofthe part of epoxy resin instead of the epoxy soybean oil system was higher than the contactAngle of epoxy soybean oil base polymer, so it had better hydrophobicity and its contact Angleof60%E44polymer is131.9°.(5)Epoxy soybean oil based polymer of the system of1-methylimidazole-HHPA buriedwith soil after four months to prove it was the biodegradable polymer through theweightlessness rate, FTIR, TG and SEM analysis of the groups change, thermal decompositionquality change and surface morphology. Degradation polymer had biggest weightlessness ratewas3.15%, thermal stability reduced, part of polymer happened mineralization.