Abstract Three star-shaped poly(ʟ-lactide)s (PLLAs) were synthesized, two 6-arm with Mw of 120 and 245 kg/mol and one 4-arm with Mw of 123 kg/mol. Linear PLLAs with Mw of 121 and 339 kg/mol were also prepared. Crystallization, both isothermal and nonisothermal, of all PLLAs was studied by means of DSC. The growth rate of spherulites was measured in a broad range of crystallization temperature using PLM. At Mw close to 120 kg/mol the star architecture slowed down the spherulite growth above 120 °C, up to 145 °C. The spherulite growth in PLLAs with Mw > 200 kg/mol was slower than that in the other polymers and unaffected by the macromolecule architecture. The differences in the spherulite growth rate were reflected in overall crystallization kinetics in isothermal conditions and also in crystallization peak temperature and crystallinity developed during cooling. The highest crystallinity developed during isothermal crystallization in linear and 6-arm PLLAs with Mw close to 120 kg/mol, whereas the lowest in PLLAs with Mw > 200 kg/mol. For Mw > 200 kg/mol the star architecture decreased the melting temperature. The glass transition temperature of all PLLAs was the same, at 61–62 °C, regardless of Mw and macromolecule architecture.

中文翻译：

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星形和线性聚（L-丙交酯）的结晶

摘要 合成了三种星形聚（ʟ-丙交酯）（PLLA），两种六臂分子量分别为120和245 kg/mol，一个四臂分子量为123 kg/mol。还制备了 Mw 为 121 和 339 kg/mol 的线性 PLLA。通过 DSC 研究了所有 PLLA 的等温和非等温结晶。使用 PLM 在广泛的结晶温度范围内测量球晶的生长速率。在 Mw 接近 120 kg/mol 时，星形结构在 120 °C 以上减缓球晶生长，最高可达 145 °C。Mw > 200 kg/mol 的 PLLA 中的球晶生长比其他聚合物中的慢，并且不受大分子结构的影响。球晶生长速率的差异反映在等温条件下的整体结晶动力学以及冷却过程中形成的结晶峰温度和结晶度。在线性和 6 臂 PLLA 的等温结晶过程中结晶度最高，Mw 接近 120 kg/mol，而在 Mw > 200 kg/mol 的 PLLA 中最低。对于 Mw > 200 kg/mol，星形结构降低了熔化温度。无论 Mw 和大分子结构如何，所有 PLLA 的玻璃化转变温度都相同，为 61–62 °C。200 kg/mol 星形结构降低了熔化温度。无论 Mw 和大分子结构如何，所有 PLLA 的玻璃化转变温度都相同，为 61–62 °C。200 kg/mol 星形结构降低了熔化温度。无论 Mw 和大分子结构如何，所有 PLLA 的玻璃化转变温度都相同，为 61–62 °C。