Bacterially synthesized poly (3-hydroxybutyrate-co-3-hydroxyhexanate) (PHBH) has attracted much attention as biodegradable plastics and potential biomaterials. However, the crystallization rate of PHBH is very low, which limits its application in plastic field. Herein, oxalamide compounds (OXA_n) with a formula of C₆H₅NHCOCONH(CH₂)_nNHCOCONHC₆H₅ (n = 2, 4, 8, 12) were tailor-made as nucleators to improve the crystallization behaviors of PHBH. The effect of aliphatic spacer length of OXA_n, i.e., -(CH₂)_n-on the nucleation behavior was investigated. The OXA_n would assemble into shish-like superstructures and PHBH crystals preferred to grow on the surfaces of the shish. The crystallization rate of PHBH/OXA_n blends increased with the spacer length of OXA_n up to n = 8 and then leveled off, which trend was consistent with the nucleation activity (Ψ) and the nucleation constant (K_g) of the OXA_n. Meanwhile, the OXA_n increased the nuclei density of the PHBH while inhibited its secondary crystallization, resulting in a superior and steady mechanical performance of PHBH materials. This work provides a scientific approach to design the optimal structure of OXA_n as nucleators for PHBH materials, which may broaden the application range of PHBH materials.

细菌合成的聚（3-羟基丁酸酯共-3- hydroxyhexanate）（PHBH）已经引起了注意，因为生物降解性塑料和潜在的生物材料。然而，PHBH的结晶速率非常低，这限制了其在塑料领域的应用。在本文中，将具有化学式C ₆ H ₅ NHCOCONH（CH ₂）_n NHCOCONHC ₆ H ₅（n = 2、4、8、12 ）的草酰胺化合物（OXA _n）定制为成核剂，以改善PHBH的结晶行为。研究了OXA _n的脂肪族间隔基长度，即-（CH ₂）_n-对成核行为的影响。OXA_n会组装成类似烤肉串的上层建筑，PHBH晶体更适合在烤肉串的表面上生长。PHBH / OXA的结晶速率_Ñ共混物与OXA的间隔长度的增加_Ñ多达n = 8，然后趋于平稳，这趋势是与核活性（Ψ）和成核常数（K一致_克的OXA的）_ñ。同时，OXA _n增加了PHBH的核密度，同时抑制了其二次结晶，从而使PHBH材料具有优异而稳定的机械性能。这项工作提供了一种科学的方法来设计OXA _n的最佳结构 作为PHBH材料的成核剂，可以扩大PHBH材料的应用范围。