Families of bio-based hyperbranched epoxy (HBPEEs) were successfully prepared using renewable xylitol, bisphenol A and epichlorohydrin as feedstocks. The structure and physical performances of HBPEEs were characterized by FTIR, NMR, GPC and viscosity evaluation. Then, they were used as high efficient tougheners for diglycidyl of bisphenol A/diethylenetriamine (DGEBA/DETA) networks. The results indicated that the incorporation of HBPEEs into the DGEBA system can significantly enhance the mechanical properties and solvent resistance properties of the hybrid (HBPEEs/DGEBA). In particular, toughened hybrids with 15 wt% HBPEE-2 exhibited the outstanding impact strength than that of neat DGEBA (37.4 kJ/m 2 vs. 11.8 kJ/m 2 ) due to its excellent compatibility of with DGEBA. Simultaneously, the ductile fracture morphology of the modified hybrids was also confirmed by SEM. In addition, the activation energies of HBPEE-2/DGEBA hybrids calculated from the non-isothermal curing kinetics were lower than that of neat DGEBA. All of the results suggested that the bio-based HBPEEs could be used as efficient tougheners applied in epoxy resins industry.
Microcalorimetry was used to monitor the heat flow of the curing reaction between glycidyl azido polymer (GAP) and various isocyanate curatives. The curing kinetics was investigated in the temperature range 308.15–323.15 K, and the activation energy , activation free energy , activation enthalpy , and activation entropy of the curing reaction between GAP and polyaryl polymethylene isocyanate (PAPI) were obtained. The thermodynamic properties of the reaction were also studied by varying the amount of PAPI at 323.15 K. The rate constant slightly increased with the increasing content of PAPI. Moreover, a model function of da/d t = 10 −4.30 (1-a) 1.62 was applied to describe the curing reaction of the GAP-PAPI binder system at 323.15 K.
危险品化学品经营许可证（带存储）