The effect of POSS-NH2 and POSS-PEG on the crystallization kinetics of poly (l-lactic acid) by traditional DSC and fast scanning chip calorimetry

• Published in: Journal of thermal analysis and calorimetry 2023-02, Vol.148 (3), p.753-766
• Main Authors: Luo, Chunyan, Fang, Minggang, Sun, Jianxin, Yang, Minrui, Chen, weixing
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Cooling; Crystallization; Differential scanning calorimetry; Heat measurement; Heating rate; Inorganic Chemistry; Kinetics; Lactic acid; Measurement Science and Instrumentation; Nucleation; Physical Chemistry; Polyethylene glycol; Polyhedral oligomeric silsesquioxane; Polymer Sciences; Thermal analysis
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-022-11833-3

Thermal analysis is an effective mean to study the crystallization of polymers. Fast scanning chip calorimetry (FSC) has ultra-high cooling and heating rate and plays an important role in the study of crystallization behavior. The crystallization kinetics of poly ( l -lactic acid) (PLLA) with amino polyhedral oligomeric silsesquioxane (POSS-NH 2 ) and polyethylene glycol-grafted POSS (POSS-PEG) was investigated by traditional differential scanning calorimetry (DSC) and FSC. The results show that the addition of POSS-PEG has a better promoting effect on the crystallization rate of PLLA than POSS-NH 2 . And there are two differences between the results of FSC and DSC: firstly, FSC can effectively avoid the nucleation and crystallization behavior in the cooling process and ensure that the crystallization process occurs completely in the isothermal stage, while DSC cannot; second, the measured crystallization rate by FSC is lower than the traditional DSC data. In a word, POSS plays a role of nucleation agent in PLLA crystallization, and PEG as nucleation accelerator further improves the crystallization rate; FSC can effectively avoid the nucleation and crystallization in the cooling and heating process.