- 學位論文
生物可分解性聚乳酸之特性、應用及分解
CHARACTERIZATION, APPLICATION, AND DEGRADATION OF BIODEGRADABLE POLYLACTIC ACID
摘要
摘要 聚乳酸 [poly(lactic acid), PLA] 和去水乳酸共聚物 (lactide copolymers) 是生物可分解和可堆肥化的聚合物材料，它是生產自可恢復的資源，具有生物相容性和在人類身體與環境中無毒性等特性。相關的研究和發展是越來越受到重視，已被廣泛地應用在包括醫學，製藥學，農業和工業等不同的領域。值得注意的是，近十年來聚乳酸聚合物已逐 漸取代了傳統的合成包裝材料。本論文主要總結歸納了聚乳酸的特性，回顧聚乳酸的生產技術，圖解說明於每個領域的最新研究與應用實例以及描述它們被生物或其他方式的降解過程。 製作聚乳酸和它的共聚物共有三種方式。目前有幾間公司以半商業等級生產的聚乳酸，已使用在生物可分解塑膠材料。PLAs 曾經被使用在組織再生的生醫材料，藥物傳遞系統的材料和其他可降低環境衝擊的商業化聚合物材料，如應用於包裝材料上。有關聚合物在動物和人類體內的降解，一般認為是經由酵素和非酵素的水解。包括有proteinase K、pronasec 和bromelain 等幾個酵素能夠降解這聚合物；然而僅有少數論文描述關於這聚合物被微生物降解的特性。有一些例如Amycolatopsis sp.的放線菌類 (actinomycete) 和例如Bacillus brevis 之適高溫細菌(thermophilic bacterium) 等聚乳酸降解微生物已被鑑定出。這些微生物的確認是利用可於含有聚乳酸粉末的洋菜皿上產生透明地帶的技術來篩選出，然而有關微生物降解乳酸聚合物作用機制仍舊是不太清楚。 聚乳酸和它的共聚物的特性和技術水準仍然有需改進之處以應用在其他的領域。一旦聚乳酸的生產工業化後，它將能夠廣泛的應用在醫學和降解塑膠等領域。
並列摘要
ABSTRACT Poly(lactide)s [i.e. poly(lactic acid) (PLA)] and lactide copolymers are polymer materials that are biodegradable, compostable, producible from renewable resources, biocompatibile, and nontoxic to the human body and the environment. Since the polymer materials have and no toxicity and can be absorbed, greater and greater attention has been paid to the related researches and development. They are increasingly applied in various areas including medicine, pharmacy, agriculture, and industry. Polylactide polymers have also gained enormous attention as a replacement for conventional synthetic packaging materials in the last decade. The aim of this issue is to summarize the main properties of PLAs, review the production techniques for PLAs, illustrate the applicated examples and advanced researches in every field, and describe their degradation by organisms or others. There are three methods for preparing polylactide and its copolymers. Several companies now produce polylactic acid (PLA) on a semi-commercial scale for using in biodegradable plastics. PLAs have been used as biomedical materials for tissue regeneration, matrices for drug delivery systems, and alternatives, such as packaging materials, for commercial polymeric materials to reduce the impact on the environment. The degradation of the polymer in animals and humans is thought to proceed via enzymatic or non-enzymatic hydrolysis. Several enzymes can degrade the polymer: proteinase K, pronase and bromelain; however, few have been characterized with regards to microbial degradation of the polymer. A few PLA-degrading microorganisms have been identified, such as actinomycete (Amycolatopsis sp.) and thermophilic bacterium (Bacillus brevis.) These organisms were identified by their ability to form a clear zone in an agar plate containing PLA powder. However, the involvement of microorganisms in the depolymerization of PLAs is still unclear. The property and technological level of polylactide and its copolymers remain to be improved for use in some areas. Once the manufacture of polylactide is industrialized, it can be of wide application in the fields of medicine and degraded plastics.