본 논문에서는 ammonium phosphate (APP)를 핵제로 사용한 PLA 필름에 대한 결정화 특성을 연구하였다. PLA 필름의 결정화도와 결정크기는 Scherrer 식을 이용하여 결정하였으며 결정화속도 상수는 Avrami 식을 이용하여 계산하였다. 본 연구에 사용한 시료는 2단계 과정을 거쳐 제조되었다. 먼저 APP를 1, 5, 10 wt% 첨가한 필름을 각각 제조하고 130, 140, $150^{circ}C$에서 어닐링시켜서 시료로 사용하였다. 순수한 PLA 필름의 결정화도는 평균 4.6%였으며 APP를 1, 5, 10 wt% 첨가한 필름의 평균 결정화도는 각각 12.2, 47.7, 50.0%였다. 순수한 PLA 필름의 평균 결정크기는 28.0 nm였으며 APP를 1, 5, 10 wt% 첨가한 필름의 평균 결정크기는 26.8, 24.0, 19.0 nm였다. APP를 1 wt% 첨가한 PLA 필름의 130, 140, $150^{circ}C$ 어닐링 온도별 결정화속도 상수는 각각 2.12, 3.86, 0.27로, $140^{circ}C$에서 어닐링시킨 PLA 필름의 결정속도가 가장 빨랐으며 순수한 필름, 5, 10 wt% 첨가한 필름보다 높았다.
In this paper, it was studied on the crystallization characteristics of PLA film by adding ammonium phosphate (APP) as a nucleation agent. Crystallinity and crystallite size of PLA film were determined by Scherrer equation. Crystallization rate constant of PLA film was calculated through Avrami equation. Film samples in the study were prepared by two steps. PLA films were prepared by adding 1, 5, and 10 wt%, respectively, at first and was secondly annealed at 130, 140, and $150^{circ}C$. Crystallinity of pure PLA film was average 4.6% and those of PLA film with adding 1, 5, and 10 wt% APP were 12.2, 47.7, and 50.0%, respectively. Crystallite size of PLA film was average 28.0 nm and those of PLA film with adding 1, 5, and 10 wt% APP were 26.8, 24.0, and 19.0 nm, respectively. Crystallization rate constants of PLA film with 1 wt% APP were 2.12, 3.86, and 0.27 by annealing at 130, 140, and $150^{circ}C$, respectively, where was higher than pure PLA film and those with adding 5 and 10 wt% APP, respectively.
