Abstract The effect of crystallization temperature and time on the melting of a stereo-copolymer of l -lactic acid has been measured using differential scanning calorimetry and hot stage microscopy. The temperature of the last trace of crystallinity increased with time and temperature. Increasing the heating rate to 50 °C min−1 and correcting for thermal lag enabled the m.pt of the as-crystallized material to be determined without premature melting and recrystallization of the sample on heating. The measured melting points enabled the equilibrium m.pt. of the copolymer to be determined as 205 ± 2 °C. Changes due to lamellae thickening occurred by secondary crystallization from the initial onset of crystallization increasing with increasing temperature consistent with the process being diffusion controlled The addition of small chain segments emerging from the top lamellar surface occurred by reptation and growth increased with the square root of the lapsed time. This is consistent with the process of secondary crystallization.

中文翻译：

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聚（L-乳酸）的熔化。

摘要 使用差示扫描量热法和热台显微镜测量了结晶温度和时间对 l-乳酸立体共聚物熔融的影响。最后一丝结晶的温度随时间和温度升高。将加热速率提高到 50 °C min-1 并校正热滞后，可以确定结晶材料的 m.pt，而不会导致样品在加热时过早熔化和再结晶。测量的熔点使平衡 m.pt。共聚物的温度确定为 205 ± 2 °C。由于从结晶初始开始的二次结晶引起的层状增厚发生的变化随着温度的升高而增加，与扩散控制的过程一致 ​​从顶部层状表面出现的小链段的添加通过爬行和生长发生，随着温度的平方根增加逝去的时间。这与二次结晶过程一致。