| Epoxy resin is one of the most important thermosets and wildly used in automobiles, ships, aerospace, electronics and electrics and many other fields owing to their excellent performances. However, the widespread application of epoxy resin is limited in some areas because of its high viscosity, low toughness and high brittleness. In our study, dimer diol derived from renewable fatty acid derivatives was used as the raw material to synthesize a biobased epoxy with low viscosity and good flexibility. Besides, curing kinetics, mechanical and thermal properties of epoxy system and its application in the field of epoxy resin were also investigated. The main results as follow:The dimer diol (trade name Pripol 2033) was used to react with epichlorohydrin in the presence of NaOH and phase transfer catalyst to synthesize the diglycidyl ether of dimer diol (DGEDD). The optimum synthesis route was determined by studying the reaction conditions. And its structure was verified by means of FT-IR and ESI-MS spectroscopy.Curing kinetics of DGEDD with hexahydrophthalic anhydride (HHPA) as curing agent and tris(dimethylaminomethyl)phenol (DMP-30) as curing accelerator was investigated by non-isothermal and isothermal DSC technique, respectively and the CHDMDGE epoxy system was perpared as a contrast. In non-isothermal kinetic study, the variation of the effective activation energy with fraction conversion was revealed by the model-free advanced isoconversional method. The further analysis with Malek method confirmed that the SB(m, n) model can predict the reaction rate well for two systems. The isothermal kinetic analysis indicated that Kamal model can give a good description to the curing process of two epoxy systems. According to the performance tests, the cured DGEDD epoxy system exhibited the characteristics of elastomers. Compared with cured CHDMDGE and HDDGE epoxy system, it had the highest elongation at break with 75.29%, the lowest tensile and shear strength at room temperature and Tg with 14.72 oC. The thermal stability of the cured DGEDD system is similar to the cured CHDMDGE system and higher than the cured HDDGE system.DGEDD was used for the modification of epoxy resin. According to the non-isothermal analysis, incorporation of DGEDD didn’t increase largely the reaction energy barrier of CYD128/HHPA/DMP-30 system and also didn’t cause significant changes of the overall curing kinetic of the pure CYD128 system. Besides, DGEDD showed satisfactory dilution capability to CYD128.Along with the increasing DGEDD load, the tensile strength and Tg of the CYD128/DGEDD blend systems were falling and the elongation at break, shear strength and impact strength were increasing. Meanwhile, addition of DGEDD had a slight drop in storage moduli of the mixed epoxy systems and maintained high thermal stabilities. DGEDD had better toughening effect and thermal properties than PPGDGE and HDDGE. The results suggest DGEDD is an excellent biobased epoxy modifier and shows utility value. It can be a good candidate to replace the petrochemical-based chemicals and products in the field of epoxy resin. |
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