Xiao Laihui, Li Wenbin, Li Shuai, Chen Jie, Wang Yigang, Huang Jinrui, Nie Xiaoan
Key Laboratory of Biomass Energy and Material, Jiangsu Province, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Province, Key Laboratory of Chemical Engineering of Forest Products, National Forestry and Grassland Administration, National Engineering Laboratory for Biomass Chemical Utilization, Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, 16 Suojin Wucun, Nanjing 210042, Jiangsu Province, P. R. China.
ACS Omega. 2021 Dec 1;6(49):34142-34149. doi: 10.1021/acsomega.1c05812. eCollection 2021 Dec 14.
Diglycidyl ether of bisphenol A (DGEBA) is a kind of widely used epoxy resin, but its thermosets normally show high brittleness and poor impact resistance due to the intrinsic rigid aromatic rings, which limit its application greatly. To avoid this drawback, we proposed a method to prepare a series of hyperbranched epoxies (HBEPs) with different molecular weights. After HBEPs were cured with methyl tetrahydrophthalic anhydride (MTHPA), characterizations were carried out to evaluate the properties of the cured HBEP samples. Testing results indicate that the hyperbranched thermosets can achieve excellent mechanical strength and toughness (tensile strength: 89.2 MPa, bending strength: 129.6 MPa, elongation at break: 6.1%, toughness: 4.5 MJ m, and impact strength: 6.7 kJ m), which are superior to those of the thermosets of commercial DGEBA (tensile strength: 81.2 MPa, bending strength: 108.2 MPa, elongation at break: 3.0%, toughness: 1.5 MJ m, and impact strength: 4.2 kJ m). In addition, HBEP with the highest molecular weight and degree of branching shows the best comprehensive mechanical properties. All hyperbranched thermosets exhibit high glass-transition temperatures ( ) and thermostability, which further illustrates the potential application value of HBEPs.
双酚A二缩水甘油醚（DGEBA）是一种广泛使用的环氧树脂，但其热固性材料通常由于固有的刚性芳环而表现出高脆性和抗冲击性差的问题，这极大地限制了其应用。为了避免这一缺点，我们提出了一种制备一系列不同分子量超支化环氧树脂（HBEP）的方法。在用甲基四氢邻苯二甲酸酐（MTHPA）固化HBEP后，进行了表征以评估固化后的HBEP样品的性能。测试结果表明，超支化热固性材料可以实现优异的机械强度和韧性（拉伸强度：89.2MPa，弯曲强度：129.6MPa，断裂伸长率：6.1%，韧性：4.5MJ/m，冲击强度：6.7kJ/m），优于商业DGEBA热固性材料（拉伸强度：81.2MPa，弯曲强度：108.2MPa，断裂伸长率：3.0%，韧性：1.5MJ/m，冲击强度：4.2kJ/m）。此外，具有最高分子量和支化度的HBEP表现出最佳的综合机械性能。所有超支化热固性材料都表现出高玻璃化转变温度（ ）和热稳定性，这进一步说明了HBEP的潜在应用价值。
