关键词: 聚丁二酸丁二醇酯, 丁二酸, 热性能, 热降解活化能

Abstract: "This study aims to investigate the influence of succinic acid raw materials from different sources on the thermal properties of poly(butylene succinate) (PBS). Commercially available petroleum-based succinic acid (SA-1) and bio-based succinic acid (SA-2) were selected as raw materials for impurity detection and subsequent synthesis of PBS samples, in order to evaluate the impact of raw material differences on the properties of PBS. First, the two types of succinic acid raw materials were characterized. The results revealed that both succinic acids contained lactic acid and fumaric acid; the total amount of Na and metal elements in SA-2 was significantly higher than that in SA-1. Subsequently, PBS samples with similar intrinsic viscosities were synthesized using these two succinic acid raw materials, and the properties of the samples were analyzed. There were noticeable differences in the color hues of the PBS samples, with PBS-2 appearing more yellowish and darker compared to PBS-1. This could be attributed to the higher total amount of Na and metal elements in SA-2, leading to more severe thermal degradation reactions during polymerization and the generation of more chromophores. Differential scanning calorimetry (DSC) curve analysis indicated that the cold crystallization peak of PBS-2 was significantly higher than that of PBS-1 in the second heating curve, and there was an obvious shoulder peak in the cooling curve of PBS-2. This might be because the thermal degradation reaction during the polymerization of PBS-2 was more severe, resulting in the production of more small-molecule compounds and altering its cold crystallization behavior. The influence of succinic acid raw materials on the thermal stability of PBS was further investigated through thermogravimetric analysis. As the heating rate increased, the maximum thermal degradation temperature of all samples shifted to higher temperatures. At a heating rate of 10 °C/min, the initial decomposition temperature of PBS-1 was lower than that of PBS-2, but as the mass loss increased, the decomposition temperature of PBS-1 gradually became higher than that of PBS-2, with a maximum decomposition temperature of 395.2 °C, higher than the 390.8 °C of PBS-2. This indicated that PBS-1 had higher thermal stability than PBS-2. The thermal degradation activation energy (Ea) was calculated using the Friedman and Flynn-Wall-Ozawa methods, and the results showed that Ea was approximately in the range of 110–160 kJ/mol, which was close to the results in related literature. Additionally, the Ea of PBS-2 was lower than that of PBS-1, further indicating that the thermal stability of PBS synthesized from bio-based succinic acid was reduced. In conclusion, there are significant differences between petroleum-based succinic acid and bio-based succinic acid, and these differences influence the properties of PBS by influencing its polymerization reaction. Compared to PBS synthesized from petroleum-based succinic acid, PBS synthesized from bio-based succinic acid exhibits reduced thermal stability. This is primarily attributed to the higher content of Na and metal elements in bio-based succinic acid, which leads to more severe thermal degradation reactions and the generation of more small-molecule compounds. These findings provide insights for optimizing PBS production processes and expanding its application scope."

Key words: poly(butylene succinate), succinic acid, thermal properties, thermal degradation activation energy