Uracil was investigated as a nucleating agent for bacterially synthesized copolymer of R-3-hydroxybutyrate and 4-hydroxybutyrate (P3HB4HB). The effects of uracil on the crystallization kinetics, melting behavior, spherulite morphology, crystalline structure and rheological behavior of P3HB4HB were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide angle X-ray diffraction (WAXD), Fourier transform infrared (FTIR) spectroscopy and rheometer. The crystallization half-times (t_1/2) of P3HB4HB decreased significantly in the presence of uracil. With addition of 1 wt% uracil, the t_1/2 value of P3HB4HB melt crystallizing at 95 °C decreased to 2.37 min, about 3.5% of the neat polymer. In-situ FTIR spectra revealed the clear interactions between uracil and P3HB4HB in composites, inducing some precursory structures. Furthermore, the storage and loss modulus of nucleated P3HB4HB increased exponentially compared with neat P3HB4HB. It was proposed that uracil is an environment friendly nucleating agent and rheological modifier for the P3HB4HB.

研究了尿嘧啶作为细菌合成的R -3-羟基丁酸酯和4-羟基丁酸酯（P3HB4HB）的成核剂。通过差示扫描量热法（DSC），偏光显微镜（POM），广角X射线衍射（WAXD），傅里叶研究了尿嘧啶对P3HB4HB的结晶动力学，熔融行为，球晶形态，晶体结构和流变行为的影响。变换红外（FTIR）光谱和流变仪。在存在尿嘧啶的情况下，P3HB4HB的结晶半衰期（t _1/2）显着降低。加入1wt％的尿嘧啶后，在95°C下结晶的P3HB4HB熔体的t _1/2值降至2.37 min，约占纯聚合物的3.5％。原位FTIR光谱显示复合物中尿嘧啶和P3HB4HB之间存在清晰的相互作用，从而诱导了一些前体结构。此外，与纯净的P3HB4HB相比，有核P3HB4HB的储能模量和损耗模量呈指数增长。有人提出，尿嘧啶是一种环境友好的成核剂和P3HB4HB的流变改性剂。