物理化学学报

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可交联且可生物降解的高分子膜

陈帅1,2, 秦江雷3,4, 杜建忠1,2   

  1. 1 同济大学附属上海市第十人民医院骨科, 同济大学医学院, 上海 200072;
    2 同济大学材料科学与工程学院高分子材料系, 上海 201804;
    3 河北大学化学与环境科学学院, 河北 保定 071002;
    4 北京化工大学有机无机复合材料国家重点实验室, 北京 100029
  • 收稿日期:2020-06-11 修回日期:2020-07-27 录用日期:2020-07-27 发布日期:2020-07-31
  • 通讯作者: 秦江雷, 杜建忠 E-mail:jzdu@tongji.edu.cn;qinhbu@iccas.ac.cn
  • 基金资助:
    河北省自然科学基金(B2018201140),有机无机复合材料国家重点实验室基金(oic-202001005),国家杰出青年科学基金(21925505)和国家自然科学基金(21674081)资助项目

Cross-Linkable Yet Biodegradable Polymer Films

Shuai Chen1,2, Jianglei Qin3,4, Jianzhong Du1,2   

  1. 1 Department of Orthopedics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai 200072, China;
    2 Department of Polymeric Materials, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China;
    3 College of Chemistry and Environmental Science, Hebei University, Baoding 071002, Hebei Province, China;
    4 State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2020-06-11 Revised:2020-07-27 Accepted:2020-07-27 Published:2020-07-31
  • Supported by:
    The project was supported by the Natural Science Foundation of Hebei Province, China (B2018201140), State Key Laboratory of Organic-Inorganic Composites, China (oic-202001005), the National Science Fund for Distinguished Young Scholars, China (21925505), and the National Natural Science Foundation of China (21674081).

摘要: 高分子膜在生物医用、电子器件、食品包装,以及气体分离等领域有着广泛的应用。实际应用中往往通过交联提高其稳定性、强度等性能。然而,传统的交联高分子膜材料在温和环境下难以降解。针对这一挑战,本文分别基于聚(α-(肉桂酰氧基甲基)-1,2,3-三唑)己内酯(PCTCL133)及其与己内酯(CL)的无规共聚物P(CL156-stat-CTCL28),通过溶液浇铸法制备了两种可交联且可生物降解的高分子膜。由于肉桂酸酯侧链阻止了PCL主链的结晶,因此PCTCL133均聚物可形成透明膜,而P(CL156-stat-CL28)无规共聚物则形成半透明膜。该高分子膜可进一步在紫外光照射下交联,而所形成的交联膜结构可以在酸催化下充分降解。理论上,这两种膜材料均可完全降解为分子量小于300 g·mol-1的产物。而通过调节聚合物中己内酯的重量百分数以及膜的交联度,可以有效调节其降解速率、透明度等性能。在此基础上,我们进一步通过分子动力学模拟探究了溶液浇铸过程中高分子的不同初始浓度对膜材料杨氏模量的影响。结果表明,随着初始浓度上升,由于分子链间的缠结程度升高,最终制备的膜材料具有更高的模量。因此,该可交联、可降解,且降解性能可调的高分子膜在生物医用领域具有一定的应用前景,并可拓展到其他领域以实现更为广泛的应用。

关键词: 高分子膜, 聚己内酯, 光交联, 可降解性, 溶液浇铸法

Abstract: Polymer films are widely used as biomaterials, electronic devices, food packaging materials and gas separation membranes. In practice, cross-linking is an effective method to enhance their stability and increase the strength of these films. However, conventional cross-linked polymer films cannot degrade under mild conditions. Herein, we fabricated two cross-linkable, yet biodegradable, polymer films of ~0.2 mm via solution casting using cinnamate-grafted polycaprolactones, namely:a poly((α-(cinnamoyloxymethyl)-1,2,3-triazol) caprolactone) (PCTCL133) homopolymer and a poly(caprolactone-stat-CTCL) (P(CL156-stat-CTCL28)) copolymer. The successful syntheses of the polymers were confirmed via proton nuclear magnetic resonance (1H NMR) spectroscopy, size exclusion chromatography (SEC), and Fourier transform infrared (FT-IR) spectroscopy. The PCTCL homopolymer appeared as a transparent film, owing to its side groups that impede its crystallinity; in contrast, the copolymer film appeared translucent, owing to its PCL segments that are easily crystallized. The cinnamate groups facilitated the cross-linking of the polymer films when irradiated by ultraviolet (UV) light; this is indicated by its insoluble character in tetrahydrofuran, which is a good solvent for both polymers. SEC analysis indicated that a fraction of the P(CL156-stat-CTCL28) film remained un-cross-linked after irradiation, owing to its crystalline structure. In contrast, UV irradiation caused the PCTCL homopolymer film to become homogeneously cross-linked, which exhibited a cross-linking density of 49% after 2 h as indicated by the 1H NMR results. Thermogravimetric analysis (TGA) indicated that cross-linking of the PCTCL films caused a minimal change in thermal stability. Both the cross-linked polymer films were able to degrade upon the addition of a modest amount of concentrated hydrochloric acid, as confirmed by SEC and 1H NMR. However, the degradation rate significantly decreased after cross-linking, thereby indicating its tunable character that can be altered by varying the cross-linking density. In addition, the rate of degradation can be adjusted upon varying the fraction of cross-linked PCTCL groups in the copolymer. In principle, treating the polymer films with sufficient amounts of acid could form degradation products with molecular weights less than 300 g·mol-1. To further explore the mechanical properties of such materials, we investigated the correlation between the initial concentration used for solution casting and the Young's modulus of the film by employing molecular dynamics simulations. These results indicate that tougher films are prepared when using more concentrated polymer solutions, owing to a higher degree of chain entanglement. In summary, the prepared films with tunable degradability are promising materials for biomedical applications. In principle, this platform could be utilized in hydrogels and coating materials for a broad scope of applications.

Key words: Polymer film, Polycaprolactone, Photocross-linking, Degradability, Solution casting

MSC2000: 

  • O648