The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Int J Biol Macromol. 2022 Oct 1;218:368-374. doi: 10.1016/j.ijbiomac.2022.07.146. Epub 2022 Jul 24.
Slow crystallization rates and poor storage stability of mechanical properties limit the widespread use of biosynthesized poly(hydroxyalkanoate)s (PHA). Hydrazide compounds (HC) with a formula of CHCONHNHCO(CH)CONHNHCOCH (n = 4 and 8) were used as PHA nucleating agents to improve the crystallization and mechanical properties. The effects of HC structure and self-assembly on the crystallization kinetics and nucleation efficiency of PHA were systematically investigated. Both HCs can be dissolved in the PHA matrix at high temperatures and then self-assemble into rod-like structures to induce crystallization of PHA. The nucleation efficiency of HC is much better than that of HC at low subcooling. With only 0.75 wt% HC, the crystallization half-life time t of PHA at 100 °C decreased by 91 % and the degree of crystallinity increased to 38.2 % with a large number of tiny nuclei. Moreover, storage stability of mechanical properties of PHA was greatly improved due to the better crystallization ability. Therefore, this work provides a basis for the design of high-efficiency nucleating agents for PHA, which is expected to improve the mechanical properties and expand the application fields of PHA.
缓慢的结晶速率和较差的机械性能储存稳定性限制了生物合成聚羟基烷酸酯（PHA）的广泛应用。具有 CHCONHNHCO(CH)CONHNHCOCH 化学式的酰肼化合物（HC）（n = 4 和 8）被用作 PHA 成核剂，以提高结晶和机械性能。系统研究了 HC 结构和自组装对 PHA 结晶动力学和成核效率的影响。两种 HC 都可以在高温下溶解在 PHA 基体中，然后自组装成棒状结构以诱导 PHA 结晶。HC 的成核效率远优于 HC 在低过冷度下。仅添加 0.75wt%的 HC，可使 PHA 在 100°C 下的结晶半衰期 t 降低 91%，结晶度提高到 38.2%，同时形成大量微小的晶核。此外，由于结晶能力的提高，PHA 的机械性能储存稳定性也得到了很大改善。因此，这项工作为 PHA 高效成核剂的设计提供了依据，有望提高其机械性能并扩大其应用领域。
