Preparation and Properties of Recyclable Vitrified Epoxy Resin Based on Transesterification
Liu Hechen1,2, Sun Zhanglin1, Liu Yunpeng1,2, Ge Qi1, Wu Xuan1
1. Hebei Key Laboratory of Green and Efficient New Electrical Materials and Equipment North China Electric Power University Baoding 071003 China; 2. State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China
Abstract：In recent years, epoxy resin composites have been widely applied in insulation equipment and module packaging, due to their exceptional performance including good heat resistance properties, excellent mechanical properties, and great insulating properties. At present, incineration and landfills are often used, wasting resources and causing serious pollution to the environment. With the world's energy shortage and environmental degradation, the development of new recyclable resin-based composites has gradually become the focus of research on environmentally friendly electrical equipment. In order to develop recyclable resin materials for the power industry, the synthesis and properties of ester-exchange-based glassy epoxy resins are investigated in this paper to explore the possibility of applying glassy epoxy resins in the power equipment manufacturing industry and their recycling properties. Firstly, the selection experiments were carried out to investigate the potential application and recovery performance of the glassy epoxy resins in the power equipment manufacturing industry, including zinc acetylacetonate, zinc acetate, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and stannous isooctanoate. The experiments showed that the catalytic effect of zinc acetylacetonate was better than that of zinc acetylacetonate at the same molar addition level, while zinc acetate was less compatible with the resin and some zinc acetate crystals remained in the resin after curing; TBD was similar to zinc acetylacetonate but the preparation process of TBD was more complicated and costly, while stannous isooctanoate was less effective and the resin was not completely cured. Therefore, zinc acetylacetonate was used as the transesterification catalyst for this experiment. The effects of the catalyst and curing agent ratios on the structural, thermal, mechanical and electrical properties of the resin were systematically investigated, with emphasis on its applicability in the power industry. The resin system exhibits good mechanical and electrical properties. After the introduction of zinc acetylacetonate, the electrical insulation properties were slightly reduced compared to the conventional epoxy resin due to the effect of zinc ions, but all electrical performance indicators met the relevant standards in the power industry. Finally, the degradation and recovery properties were explored using physical hot-pressure recovery and thermal dissolution of alcohol solvents. The recovered Vitrimer resin was crushed and recovered by physical hot pressing at 180℃ and 10MPa, and the mechanical strength of the recovered resin was about 76% and the electrical insulation strength was 90%.The chemical degradation recovery rate increased with the increase of zinc acetylacetonate catalyst in the resin system, and the dissolved alcohol solvent and resin mixed solution could be separated by reduced pressure distillation. The recovered resin oligomers can be recycled as part of a new resin replacement in a new curing system, and the separated alcohol solvent can be reused as a degradation solution to achieve closed-loop recycling and thus avoid wastage of reagents. The Vitrimer resin system has excellent electrical insulation properties and can be recycled at the same time, offering the possibility of recycling resin-based electrical equipment and recycling high-value materials such as internal copper windings and carbon fibres, and is expected to provide a new direction of choice for environmentally friendly electrical equipment materials.
刘贺晨, 孙章林, 刘云鹏, 葛琦, 吴璇. 基于酯交换的可回收类玻璃化环氧树备与性能研究[J]. 电工技术学报, 0, (): 40-40.
Liu Hechen, Sun Zhanglin, Liu Yunpeng, Ge Qi, Wu Xuan. Preparation and Properties of Recyclable Vitrified Epoxy Resin Based on Transesterification. Transactions of China Electrotechnical Society, 0, (): 40-40.
[1] 陈平, 刘胜平, 王德中. 环氧树脂及其应用[M]. 北京: 化学工业出版社, 2011. [2] 杜伯学, 张莹, 孔晓晓, 等. 环氧树脂绝缘电树枝劣化研究进展[J]. 电工技术学报, 2022, 37(5): 1128-1135, 1157. Du Boxue, Zhang Ying, Kong Xiaoxiao, et al.Research progress on electrical tree in epoxy resin insulation[J]. Transactions of China Electrotechnical Society, 2022, 37(5): 1128-1135, 1157. [3] 王艳萍, 刘晓琴, 井新利, 等. 环氧树脂类玻璃高分子研究进展[J]. 化学通报, 2021, 84(4): 313-321. Wang Yanping, Liu Xiaoqin, Jing Xinli, et al.Research progress in epoxy vitrimer[J]. Chemistry, 2021, 84(4): 313-321. [4] 周松松, 杜怡君, 王晰, 等. 我国户外复合绝缘子用环氧树脂基复合材料的应用现状及问题讨论[J]. 中国标准化, 2021(增刊1): 222-228. Zhou Songsong, Du Yijun, Wang Xi, et al.Application status and problems of epoxy resin matrix composites for outdoor composite insulators in China[J]. China Standardization, 2021(S1): 222-228. [5] 徐锡威. 可回收热固性环氧树脂的合成、表征及应用[D]. 杭州: 浙江工业大学, 2020. [6] 刘湍, 费铭恩, 赵保明, 等. 生物基类玻璃高分子材料的研究进展[J]. 高分子学报, 2020, 51(8): 817-832. Liu Tuan, Fei Mingen, Zhao Baoming, et al.Progress in biobased vitrimers[J]. Acta Polymerica Sinica, 2020, 51(8): 817-832. [7] Dandy L O, Oliveux G, Wood J, et al.Counting carbon fibres by electrical resistance measurement[J]. Composites Part A: Applied Science and Manufacturing, 2015, 68: 276-281. [8] Fortman D J, Brutman J P, Cramer C J, et al.Mechanically activated, catalyst-free polyhydro-xyurethane vitrimers[J]. Journal of the American Chemical Society, 2015, 137(44): 14019-14022. [9] Montarnal D, Capelot M, Tournilhac F, et al.Silica-like malleable materials from permanent organic networks[J]. Science, 2011, 334(6058): 965-968. [10] 张希. 可多次塑型、易修复及耐低温的三维动态高分子结构[J]. 高分子学报, 2016(6): 685-687. Zhang Xi.Reconfigurable, easy repairable and low-temperature resistant dynamic 3D polymer structures[J]. Acta Polymerica Sinica, 2016(6): 685-687. [11] Oliveux G, Dandy L O, Leeke G A.Current status of recycling of fibre reinforced polymers: review of technologies, reuse and resulting properties[J]. Progress in Materials Science, 2015, 72: 61-99. [12] Otera J.Transesterification[J]. Chemical Reviews, 1993, 93(4): 1449-1470. [13] 张泽平, 容敏智, 章明秋. 基于可逆共价化学的交联聚合物加工成型研究——聚合物工程发展的新挑战[J]. 高分子学报, 2018(7): 829-852. Zhang Zeping, Rong Minzhi, Zhang Mingqiu.Research progress of processing of crosslinked polymers based on reversible covalent chemistry: a new challenge to the development of polymer engineering[J]. Acta Polymerica Sinica, 2018(7): 829-852. [14] 汪东, 李丽英, 柯红军, 等. 高性能可回收环氧树脂及其复合材料的制备与性能研究[J]. 高分子学报, 2020, 51(3): 303-310. Wang Dong, Li Liying, Ke Hongjun, et al.Preparation and properties of recyclable high-performance epoxy resins and composites[J]. Acta Polymerica Sinica, 2020, 51(3): 303-310. [15] 廉维强. 酚醛改性环氧vitrimer复合材料的制备及其自修复性能研究[D]. 秦皇岛: 燕山大学, 2021. [16] Capelot M, Unterlass M M, Tournilhac F, et al.Catalytic control of the vitrimer glass transition[J]. ACS Macro Letters, 2012, 1(7): 789-792. [17] 刘贺晨, 郭展鹏, 李岩, 等. 衣康酸基环氧树脂和双酚A环氧树脂性能对比研究[J]. 电工技术学报, 2022, 37(9): 2366-2376. Liu Hechen, Guo Zhanpeng, Li Yan, et al.Comparative study on the performance of itaconic acid based epoxy resin and bisphenol A epoxy resin[J]. Transactions of China Electrotechnical Society, 2022, 37(9): 2366-2376. [18] 龚良辉, 代金月, 王帅朋, 等. 可降解生物基热固性树脂的合成和性能研究[J]. 热固性树脂, 2022, 37(2): 31-36, 41. Gong Lianghui, Dai Jinyue, Wang Shuaipeng, et al.Synthesis and properties of degradable bio-based thermosetting resin[J]. Thermosetting Resin, 2022, 37(2): 31-36, 41. [19] 郝树杰, 周威, 潘政, 等. 动态可逆交联聚合物的研究进展[J]. 热固性树脂, 2021, 36(2): 52-59. Hao Shujie, Zhou Wei, Pan Zheng, et al.Research progress in dynamically reversible cross-linked polymers[J]. Thermosetting Resin, 2021, 36(2): 52-59. [20] 杜勇, 姚京松, 吴向东, 等. 表面氟化的环氧/玻璃纤维复合绝缘的表面性能与耐放电性能[J]. 高电压技术, 2018, 44(12): 3791-3797. Du Yong, Yao Jingsong, Wu Xiangdong, et al.Surface properties and discharge resistance of surface fluorinated epoxy/fiberglass composite insulators[J]. High Voltage Engineering, 2018, 44(12): 3791-3797. [21] 田春雷, 刘振宇, 武洪文. 高吸水性材料应用及研究进展[J]. 包装工程, 2007, 28(12): 270-272. Tian Chunlei, Liu Zhenyu, Wu Hongwen.Application and recent progress on superabsorvent material[J]. Packaging Engineering, 2007, 28(12): 270-272. [22] 付东升, 张康助, 孙福林, 等. 电器灌注用环氧树脂的研究进展[J]. 绝缘材料, 2003, 36(2): 30-33. Fu Dongsheng, Zhang Kangzhu, Sun Fulin, et al.Recent advances in epoxy resin pouring sizing for electrical engineering[J]. Insulating Materials, 2003, 36(2): 30-33. [23] 缪昌文, 冉千平, 洪锦祥, 等. 聚羧酸系高性能减水剂的研究现状及发展趋势[J]. 中国材料进展, 2009, 28(11): 36-45, 53. Miao Changwen, Ran Qianping, Hong Jinxiang, et al.Present situation and developmental trends of polycarboxylate-type superplasticizers[J]. Materials China, 2009, 28(11): 36-45, 53. [24] Denissen W, Winne J M, Du Prez F E. Vitrimers: permanent organic networks with glass-like fluidity[J]. Chemical Science, 2016, 7(1): 30-38. [25] Imbernon L, Norvez S.From landfilling to vitrimer chemistry in rubber life cycle[J]. European Polymer Journal, 2016, 82: 347-376. [26] Bhusal S, Oh C, Kang Y, et al.Transesterification in vitrimer polymers using bifunctional catalysts: modeled with solution-phase experimental rates and theoretical analysis of efficiency and mechanisms[J]. The Journal of Physical Chemistry B, 2021, 125(9): 2411-2424. [27] 刘忠. 盲样泄漏电流测试分析[J]. 中国设备工程, 2021(3): 174-175. [28] 文豪, 张晓星, 伍云健, 等. 高导热钛酸锶/环氧树脂纳米复合材料的绝缘特性[J]. 高电压技术, 2019, 45(4): 1225-1233. Wen Hao, Zhang Xiaoxing, Wu Yunjian, et al.Dielectric properties of SrTiO3/epoxy nanocomposites with high thermal conductivity[J]. High Voltage Engineering, 2019, 45(4): 1225-1233. [29] 李鹏新, 崔浩喆, 邢照亮, 等. 环氧/POSS复合电介质介电与热学性能[J]. 电工技术学报, 2022, 37(2): 291-298. Li Pengxin, Cui Haozhe, Xing Zhaoliang, et al.Dielectric and thermal properties of epoxy/POSS composites[J]. Transactions of China Electrotechnical Society, 2022, 37(2): 291-298. [30] 谢伟, 杨征, 程显, 等. 环氧树脂材料热氧老化特性研究[J]. 电工技术学报, 2020, 35(20): 4397-4404. Xie Wei, Yang Zheng, Cheng Xian, et al.Study on thermo-oxygen aging characteristics of epoxy resin material[J]. Transactions of China Electrotechnical Society, 2020, 35(20): 4397-4404. [31] Zheng J, Png Z M, Ng S H, et al.Vitrimers: Current research trends and their emerging applications[J]. Materials Today, 2021, 51: 586-625. [32] 梁琛, 司马文霞, 孙魄韬, 等. 单组分光敏微胶囊/纳米SiO2/环氧树脂复合绝缘介质的自修复特性[J]. 电工技术学报, 2022, 37(6): 1564-1571. Liang Chen, Sima Wenxia, Sun Potao, et al.Self-healing property of one-component photosensitive microcapsule/nano-SiO2/epoxy composite dielectric[J]. Transactions of China Electrotechnical Society, 2022, 37(6): 1564-1571. [33] Mu Quanyi, An Le, Hu Zhiqiang, et al.Fast and sustainable recycling of epoxy and composites using mixed solvents[J]. Polymer Degradation and Stability, 2022, 199: 109895.
