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研究论文

苯并己内酯的开环聚合及其与环氧化合物共聚合研究

石力双†,a, 戴雅男†,a, 伍伟豪a, 李世辉*,b, 牟泽怀*,a   

  1. a 宁波大学材料科学与化学工程学院 宁波 315211;
    b 中国科学院长春应用化学研究所 高分子物理与化学国家重点实验室 长春 130022
  • 投稿日期:2025-06-17
  • 通讯作者: * E-mail: shihui-li@ciac.ac.cn; mouzehuai@nbu.edu.cn
  • 基金资助:
    项目受宁波市自然科学基金(2024J113)和高分子物理与化学国家重点实验室开放课题基金(PPCL2023-20)资助.

Ring-opening Polymerization of Benzo-fused Caprolactone and its Copolymerization with Epoxides

Li-shuang Shi†,a, Ya-nan Dai†,a, Wei-hao Wua, Shi-hui Li*,b, Ze-huai Mou*,a   

  1. a School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China;
    b State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022
  • Received:2025-06-17
  • About author:These authors contributed equally to this work
  • Supported by:
    Ningbo Natural Science Foundation (No. 2024J113), and the Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (PPCL2023-20).

聚酯作为一类重要的高分子材料,凭借其优异的性能在众多领域得到广泛应用,并在全球塑料市场中占据约10%的份额,对塑料经济的发展起到了关键作用. 然而,废弃塑料所带来的日益严重的环境问题,促使学术界和工业界将目光聚焦于开发具有闭环化学回收性能的新型聚酯材料. 本文以市售的α-四氢萘酮作为起始原料,通过简单的Baeyer-Villiger氧化反应合成了一种芳香族苯并己内酯单体,即4,5-二氢苯并[b]氧杂卓-2(3H)-酮(4,5-dihydrobenzo[b]oxepin-2(3H)-one (DHBO)). 利用1,5,7-三氮杂二环[4,4,0]癸-5-烯(TBD)为催化剂,深入研究了不同聚合条件下DHBO的开环聚合行为,制备了一种玻璃化转变温度Tg为4.8 ℃,热分解温度Td,5%为194 ℃的聚合物Poly(DHBO). 动力学实验表明在甲苯中聚合速率对单体浓度为一级反应. 该聚合物在无催化剂、110 ℃减压条件下能快速热降解为原始单体DHBO,单体回收率高达97%,纯度达到99%,展现出优异的化学回收性能. 此外,本文以双(三苯基正膦基)氯化铵(PPNCl)为催化剂,采用本体熔融聚合方法,使DHBO与多种环氧化合物(苯基缩水甘油醚(PGE)、烯丙基缩水甘油醚(AGE)、1,2-环氧丁烷(BO)、(R)-BO、(S)-BO、1,2-环氧己烷(HO)及环氧环己烷(CHO))发生开环共聚反应,成功制备了一系列聚(醚-酯)材料. 采用核磁共振氢谱(1H NMR)、碳谱(13C NMR)、扩散排序谱(DOSY NMR)以及基质辅助激光解吸飞行时间质谱(MALDI-TOF MS)对代表性共聚合物进行表征,证实所得聚(醚-酯)为含有醚键和酯基高度交替序列的共聚物. 通过对这些交替共聚物的形成机理进行深入探究,进一步揭示了其独特的聚合反应机制.

关键词: 芳香族聚酯, 闭环化学回收, 开环聚合, 交替共聚物, 聚(醚-酯)

As an important type of polymer material, polyester is widely used due to its diverse properties and plays a significant role in the plastic economy, accounting for about 10% of the global plastic market. Facing the environmental problems caused by discarded plastics, the development of new types of polyesters with closed-loop chemical recycling properties has become the focus of attention in both academic and industrial research. In this paper, benzo-fused caprolactone 4,5-dihydrobenzo[b]oxepin-2(3H)-one (DHBO) was synthesized from α-tetrahydronaphthone via Baeyer-Villiger oxidation reaction, and structurally characterized via NMR spectroscopy and single crystal X-ray diffraction. The ring-opening polymerization of DHBO under varied conditions was investigated using 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as the catalyst, and the molecular weights of the resultant Poly(DHBO) obtained via gel permeation chromatography are lower than theoretical values due to transesterification. The polymerization kinetics of DHBO in toluene with TBD/4-MeBnOH shows a first-order dependence on DHBO concentration. The Poly(DHBO) is amorphous with a glass transition temperature Tg of 4.8 ℃, and a thermal decomposition temperature Td (5% weight loss) of 194 ℃, which can be enhanced to 252 ℃ by capped the chain-end OH group with acetyl. In addition, the polyester can be rapidly thermally degraded into the initial monomer DHBO without any catalyst at 110 ℃ under reduced pressure, with a recovery rate of 97% and a monomer purity of 99%. Moreover, using bis(triphenylphosphine) iminium chloride (PPNCl) as the catalyst, DHBO can undergo ring-opening copolymerization with commercial epoxides, such as phenyl glycidyl ether (PGE), allyl glycidyl ether (AGE), 1,2-butylene oxide (BO), (R)-(BO), (S)-(BO), 1,2-hexene oxide (HO) and cyclohexene oxide (CHO) in bulk, producing poly(ether-ester) with highly alternating sequences. Representative copolymers were characterized with NMR spectroscopy (1H, 13C, DOSY) and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS). These poly(ether-ester)s showed good thermal stability with Td over 290 ℃, where the Poly((S)-BO-alt-DHBO) exhibited the highest Td of 353 ℃. The structure of epoxides effected the Tgs of corresponding poly(ether-ester), and wide range of Tg from -19 ℃ to 43 ℃ can be regulated. Finally, the mechanism of the alternating poly(ether-ester) formation was investigated.

Key words: Aromatic polyester, Closed-loop chemical recycling, Ring-opening polymerization, Alternating polymer, Poly(ether-ester)