School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, PR China; Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, PR China.
School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, PR China.
Int J Biol Macromol. 2024 Jan;254(Pt 2):127760. doi: 10.1016/j.ijbiomac.2023.127760. Epub 2023 Nov 4.
The application of epoxidized soybean oil (ESO) in thermosetting polymers is impeded by its unsatisfactory thermomechanical properties. Here, in order to address the limitation, technical lignin was modified by tung oil anhydride and then used as the hardener to compensate for the inherent flexibility defects of ESO thermosets (TLs). As the lignin content increased, a notable improvement in the activation energy of TLs was observed, attributed to the restraining effect of lignin's rigid structure on segmental relaxation. Concurrently, the tensile strength of TLs increased from 2.8 MPa to 34.0 MPa, concomitant with a decrease in elongation at break from 32.9 % to 8.0 %. Comparative analysis with TL-0 (devoid of lignin) demonstrated substantial enhancements in glass transition temperature, shape fixation ratio, and shape recovery ratio for TL-50 (comprising 50 wt% of lignin), elevating from 16.9 °C, 89.1 %, and 89.5 % to 118.6 °C, 94.0 %, and 99.3 %, respectively. These results unequivocally highlight the favorable dynamic mechanical and shape memory properties conferred upon TLs by lignin addition. While the introduction of lignin adversely affected thermal stability, a notable improvement in char yield (800 °C) was observed. Collectively, these findings underscore the potential of technical lignin as a promising bio-based curing agent for ESO.
环氧化大豆油（ESO）在热固性聚合物中的应用受到其不尽人意的热机械性能的阻碍。在这里，为了解决这一限制，术木质素通过桐油酐进行了改性，然后用作固化剂来弥补 ESO 热固性树脂（TLs）固有的柔韧性缺陷。随着木质素含量的增加，TLs 的活化能显著提高，这归因于木质素刚性结构对链段松弛的抑制作用。同时，TLs 的拉伸强度从 2.8 MPa 增加到 34.0 MPa，断裂伸长率从 32.9%降低到 8.0%。与不含木质素的 TL-0 进行比较分析表明，TL-50（含有 50wt%木质素）的玻璃化转变温度、形状固定率和形状回复率都有显著提高，从 16.9°C、89.1%和 89.5%分别提高到 118.6°C、94.0%和 99.3%。这些结果明确表明木质素的加入赋予了 TLs 有利的动态力学和形状记忆性能。尽管木质素的引入对热稳定性产生了不利影响，但观察到在 800°C 时的残炭产率有显著提高。总的来说，这些发现强调了技术木质素作为 ESO 的有前途的生物基固化剂的潜力。
