Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing, 100875, P. R. China.
Department of Chemical and Material Engineering, Yingkou Institute of Technology, Yingkou, Liaoning, 115000, P. R. China.
Macromol Rapid Commun. 2018 May;39(9):e1800050. doi: 10.1002/marc.201800050. Epub 2018 Mar 13.
A novel type of polymeric material with tunable mechanical properties is fabricated from polymers and small molecules that can form hydrogen-bonded intermolecular complexes (IMCs). In this work, poly(vinyl alcohol) (PVA)-glycerol hydrogels are first prepared, and then they are dried to form IMCs. The tensile strengths and moduli of IMCs decrease dramatically with increasing glycerol content, while the elongations increase gradually. The mechanical properties are comparable with or even superior to those of common engineering plastics and rubbers. The IMCs with high glycerol content also show excellent flexibility and cold-resistance at subzero temperatures. Cyclic tensile and stress relaxation tests prove that there is an effective energy dissipation mechanism in IMCs and dynamic mechanical analysis confirms their physical crosslinking nature. FTIR and NMR characterizations prove the existence of hydrogen bonding between glycerol and PVA chains, which suppresses the crystallization of PVA from X-ray diffraction measurement. These PVA-glycerol IMCs may find potential applications in barrier films, biomedical packaging, etc., in the future.
一种新型的聚合物材料，具有可调节的机械性能，是由聚合物和小分子组成的，这些小分子可以形成氢键的分子间复合物（IMCs）。在这项工作中，首先制备了聚乙烯醇（PVA）-甘油水凝胶，然后将其干燥形成 IMCs。IMCs 的拉伸强度和模量随着甘油含量的增加而显著降低，而伸长率逐渐增加。其机械性能可与常见的工程塑料和橡胶相媲美，甚至更优。高甘油含量的 IMCs 也表现出优异的柔韧性和在零下温度的耐寒性。循环拉伸和应力松弛测试证明 IMCs 中有一个有效的能量耗散机制，动态力学分析证实了它们的物理交联性质。傅里叶变换红外光谱（FTIR）和核磁共振（NMR）表征证明了甘油和 PVA 链之间存在氢键，这从 X 射线衍射测量中抑制了 PVA 的结晶。这些 PVA-甘油 IMCs 在未来可能在阻隔膜、生物医学包装等领域有潜在的应用。
