木質纖維強化聚乳酸複合材料之製備與特性研究

Processing and Characterization of PLA Composites Reinforced with Lignocellulosic Fiber Prepared from Wood Particles

涂曉蓉(Shiau-Rung Tu)

指導教授 ： 余琬琴

國立臺北科技大學/工程學院/有機高分子研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00278

摘要

聚乳酸是一種常見的生物分解性高分子，由可再生資源製成，在很多領域中，具有取代石化產業塑膠製品的潛力。然而聚乳酸的價格高、質地脆、韌性低，聚乳酸應用的範圍因此受到限制。本研究藉由聚乳酸與生物纖維的摻混來降低材料的成本，並且探討改善材料性質的可能性。
本研究以雙螺桿混煉機製備聚乳酸/木質纖維生物性複合材料，所使用的天然纖維原料是台灣常見的相思木屑。相思木屑可分為未處理、經蒸煮爆碎（170℃、210℃）與水洗、以及蒸爆後再施以鹼性過氧化處理三類，藉此有系統的探討纖維處理方式與其添加量（5 wt%、10 wt%、20 wt%）對複合材料熱性質與機械性質的影響。複合材料斷面的微結構也以掃描式電子顯微鏡觀察。研究結果顯示，添加相思木纖維可顯著提升複合材料的衝擊強度，尤其是添加20 wt%經170℃蒸爆與鹼性過氧化處理的纖維時，衝擊強度為純聚乳酸的兩倍。另外，動態機械分析結果顯示，添加蒸爆過的纖維可提升複合材料的玻璃轉移溫度與儲存模數。

關鍵字

相思木 ； 聚乳酸 ； 生物可分解材料木質纖維 ； 蒸煮爆碎

並列摘要

Poly (lactic acid) (PLA) is a commercially available biodegradable polymer derived from renewable resources. PLA offers a potential alternative to petrochemical-based plastics in many applications; however, the relatively high price, brittleness, and low toughness of PLA limit it wide application, with renewable biofiber provides a convenient approach to tailor the material cost and engineer the material properties.
In this study, environmentally friendly biocomposites, composed of PLA and wood fibers derived from Acacia confusa wood powders, were prepared with a twin screw extruder. The wood powder were either used in their native state or subjected to various treatments prior to blending. The treatments used were steam explosion (SE) at 170℃or 210℃, followed by either hot water wash or the alkaline peroxide (AP) treatment. The mechanical and thermal properties of the resulting composites were investigated as a function of wood powder treatment methods and wood fiber contents (5 wt%, 10 wt%, 20 wt%), while the microstructures of the composites were examined with SEM. Results show that the incorporation of steam-exploded wood powders significantly improved the impact strength. Compared with the pure PLA, the impact strength was doubled when a fiber content of 20 wt% was used, and the wood powders received the combined SE (at 170℃) and AP treatment. The dynamic mechanical analysis also indicates that the glass transition temperature (Tg) and the storage modulus increased with the addition of fibers prepared by steam explosion.

並列關鍵字

Acacia confusa particles ； Poly ( lactic acid) ； steam explosion ； biodegradable polymer ； lignocellulose

參考文獻

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