Nonisothermal Melt Crystallization Kinetics of PHB/babassu Compounds

PHB has interesting features such as biodegradability, sustainability and durability. However, it has a high cost, in addition to being hard, brittle and thermally unstable during processing. Therefore, it was found convenient to study the crystallization of PHB/20% babassu compounds, with the intention of reducing the cost of the composite, in addition to seeking improvements in thermal properties. In this work, the parameters of melt crystallization were studied for PHB/20% babassu compounds driven at different cooling rates under a nitrogen flow. Subsequently, crystallization parameters were compared for different cooling rates. A kinetic analysis of data obtained for melt crystallization was performed. Among the models studied, Pseudo-Avrami showed the best correlation with experimental data, with discrepancy between +6% and -4%. The Mo model presented a discrepancy between +15% and -8%. A modified Mo model discrepancies are reduced to +3% and -4% within the range of validity of the model.

聚羟基丁酸酯（PHB）具备可生物降解性、可持续性与耐用性等优异特性，但同时存在成本高昂的缺陷，且质地坚硬、脆性较强，加工过程中热稳定性欠佳。因此，对PHB/20%巴巴苏（babassu）复合体系的结晶行为开展研究颇具意义，以期降低该复合材料的成本，同时优化其热学性能。本研究针对氮气气流氛围下、以不同冷却速率进行的PHB/20%巴巴苏复合体系的熔融结晶参数展开了系统探究；随后对比了不同冷却速率条件下的结晶参数，并对熔融结晶实验获取的数据开展了动力学分析。在所考察的诸多模型中，伪阿夫拉米（Pseudo-Avrami）模型与实验数据的拟合相关性最优，偏差区间为+6%至-4%；莫（Mo）模型的偏差区间为+15%至-8%；而经改进的莫模型在其有效适用范围内，偏差可被压缩至+3%至-4%。