Dandan Zhang,Rumin Wang,Shameel Farhan,Yinru Cai,Jie Liu
In this study, 1,4-cyclohexanedimethanol diglycidyl ether (EP-1) has been synthesized via a two-step process to toughen and lower the viscosity of TDE-85 epoxy first time and suitable for the resin transfer molding (RTM) process. Chemical structure of EP-1 and the reactivity, rheological and mechanical properties of TDE-85/MeTHPA/DMP-30/EP-1 system were studied. When the composition ratio of TDE-85/MeTHPA/EP-1/DMP-30 is 100: 140: 15: 1 and the curing process is 80 °C/2 h + 110 °C/2 h + 140 °C/2 h, the overall performance of the resin system reached to an optimal value. Impact and bending strength of the casting came out to be 27.64 kJ m −2 and 167.2 MPa, which improved 75.16% and 17.50% respectively compared to the pristine resin system without EP-1. Dynamic viscosity analysis of TDE-85/MeTHPA/DMP-30/EP-1 system showed that the viscosity-temperature curve was U-shaped and the platform zone was located around 60–95 °C during which the viscosity was less than 200 mPa s. Dual-Arrhenius and engineering viscosity models were established to predict the viscosity characteristics of the resin. It was found that the dual-Arrhenius model matched better with the experimental data at low temperature and low viscosity region. Whereas when the viscosity increased, the engineering viscosity model became more accurate. The viscosity analysis provided the basis for the window prediction of RTM molding process.
Long Liu,Sheng Gao,Zhiyi Jiang,Yanqiang Zhang,Dayong Gui,Suojiang Zhang
A series of amide-functionalized ionic liquids (ILs), e.g., 1-R-3-(2-amino-2-oxoethyl)-imidazolium (R = −vinyl, −methyl–butyl) cations combined with Cl–, N(CN)2–, or NTf2– anions, were synthesized and fully characterized as curing agent for diglycidyl-4,5-epoxy-cyclohexane-1,2-dicarboxylate (TDE-85). Studies of curing behaviors showed that ILs with N(CN)2– anions exhibit moderate curing conditions. As to thermosets of TDE-85 cured by these curing agents, their tensile strength (95.1–111.7 MPa) and elongation at break (2.69 to 4.20%) are significantly improved compared with the traditional curing systems of DDS/TDE-85 (DDS, 4,4′-diamino diphenyl sulphone). These thermosets also exhibit good thermal mechanical properties with the glass transition temperature (Tg) > 200 °C and thermal degradation temperature (Td) > 300 °C. The possible mechanisms of curing reactions were analyzed by using IR, and results indicated that curing reactions of TDE-85 with amide-functionalized ionic liquids may include three steps, −NH2 groups reacted with oxirane at lower temperatures, and then the anions further participated in the reaction to strengthen the cross-linking networks. This study provides informative guidelines for designing new curing agents.
With the development of alternate electrical power system and the improvement of voltage level, the operation conditions faced by epoxy resin (ER) insulation materials are becoming more and more complex. The traditional ER materials have been difficult to meet the increasingly stringent requirements. In this paper, the thermal and mechanical properties of DGEBA/TDE-85/MTHPA blend system were studied by molecular dynamics (MD) simulation and experiment. The results show that the addition of TDE-85 can significantly improve the thermal and mechanical properties, and the comprehensive improvement effect is the best when the molar ratio of DGEBA and TDE-85 is about 8:2. The experimental results are consistent with the simulation results. Further analysis of the micro-parameters of the monomer and the cross-linking network found that the torsional energy barrier of TDE-85 is higher than DGEBA. And the compatibility of the two ER is better when the ratio is 8:2. In addition, TDE-85 can introduce high-stability Y-nodes into the system, making the cross-linked network more stable, which has a significant effect on improving the thermal and mechanical properties. The research provide a reference for the blending modification of high-performance ER for high-voltage insulation.
Huiyu Luo,Yaqing Yin,Yong Wang,Qingyun Li,Aixing Tang,Youyan Liu
Soybean-based wood adhesives have good application prospects, but their low water resistance limits their application in plywood manufacturing. In this study, cycloaliphatic epoxy resin 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester (TDE-85) was used as a modifier to prepare a highly water-resistant soybean adhesive. When TDE-85 was added in an amount of only 2.5 wt%, the wet shear strength of three-layer plywood pressed by the soybean adhesive increased from 0.32 MPa to 0.79 MPa, reaching the national standard for class II plywood GB/T 9846–2015. A denser fracture surface was observed with the modified adhesive than without the adhesive using scanning electron microscopy (SEM). This result was thought to be due to the participation of glycidyl ester epoxy groups and alicyclic epoxy groups in the curing reaction of soybean adhesive, as suggested by Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). By further comparing the modification effects of TDE-85 and trimethylolpropane triglycidyl ether (THPTG), it was deduced that the special epoxy group and alicyclic structure in TDE-85 may be another important factor associated with its better modification effect, thus offering new suggestions for soybean-based wood adhesives modification.
危险品化学品经营许可证（带存储）