聚乳酸／幾丁聚醣／非晶性磷酸鈣複合材料之可塑性探討

A Mechanistic Study of Shapeable PLA/Chitosan/ACP Composites

楊正昌(Jen-Chang Yang) ； 廖啟宏(Chi-Hung Liao) ； 陳建中(Chien-Chung Chen) ； 鄧乃嘉(Nai-Chia Teng) ； 黃濬賢(Chun-Hsien Huang) ； 吳宏達(Hong-Dah Wu) ； 李勝揚(Sheng-Yang Lee)

《中華牙醫學雜誌（中文版）》 25卷1期 (2006/03) Pp. 25-35

https://doi.org/10.7106/CJD.200603.0025

摘要

本研究目的在探討聚乳酸／幾丁聚醣／非晶性磷酸鈣(PLA/chitosan/ACP)複合村的可塑形特性與機制。將不同組成比例之PLA/chitosan/ACP溶於N-甲基吡啶烷酮/乳酸溶液之共溶劑中，經水洗因化沉澱後可得白色片狀物，經靜置於室溫下48小時後，複合村體積呈現膨脹且具有可塑形性，以熱重分析儀與流變儀分析不同組成樣品之含水率與屈伏應力，並以光學顯微鏡觀察其形態結構。結果顯示未添加ACP之複合村，含水率與屈伏應力分別為25wt%與l,000.0Pa，當ACP含量為0.1wt%時，含水率提高至42.5wt%，屈伏應力降為25.1Pa，ACP含量增加至0.30wt%時，複合村之含水率則降至26.4wt%，當ACP含量為10.00wt%，含水率僅6.4wt%，但是屈伏應力則大幅提升至7,943.0Pa，在光學顯微鏡下，ACP含量在0.30wt%或更高時，可觀察到未溶解的ACP顆粒。據此推論PLA/chitosan/ACP複合村之可塑性機轉為，ACP解離後之離子與幾丁聚醣透過整合或靜電吸引形成具吸水性之離子團簇(ionic cluster)，而分散於疏水性之聚乳酸中，此結構近似離子結合體(ionomer)之複合村由於吸濕後之水份塑化作用使其具可塑性與親水性，而所添加過量卻未能溶解的ACP顆粒則因分佈在基材內而提高複合材之屈伏應力。

關鍵字

可塑性 ； 聚乳酸 ； 幾丁聚醣 ； 非晶性磷酸鈣

並列摘要

The purpose of this study was to explore the effects of poly (lactic acid) (PLA)/chitosan/amorphous calcium phosphate (ACP) composites on their shapeable properties. PLA/chitosan/ACP composites containing different proportions of ingredients were prepared by water-washing solidification from an n-methyl-2-pyrrolidone (NMP)/lactic acid/water co-solution. After storing at room temperature for 48 hours, the composites showed swelling and shapeable properties. The water content and yield stress of the samples were measured by thermal gravimetric analysis (TGA) and a rheometer and examined under optical microscopy. Results showed that the composites without ACP had 1000 Pa of yield stress. For composites containing 0.0lwt% of ACP, the water content increased to 42.50wt%. The lowest yield stress was 10.0Pa in 0.30wt% ACP. When the ACP content was 0.30wt% or higher, insoluble ACP particles were observed with optical microscopy. This reveals that the shapeable properties of the PLA/chitosan/ACP composites were closely related to the water content. It was determined that ions released from the ACP interacts with amide groups of the chitosan to form water-absorbing ionic clusters through chelation or electrostatic interactions. These ionic clusters reside within the matrix while the remaining insoluble ACP particles act as a filler; as the amount of ACP increases, the yield stress of the PLA/chitosan/ACP composites also increases.

並列關鍵字

shapeable ； poly lactic acid ； Chitosan ； amorphous calcium phosphate