聚乳酸/氫氧化鋁/奈米黏土複合材料之阻燃性質

Flame retardant properties of Polylactide/Aluminum Hydroxide/Nanoclay composite

余承儐(Cheng-Bin Yu)

指導教授 ： 莊祖煌 ； 鄭國忠

國立臺北科技大學/工程學院/化學工程研究所/碩士(2010年)

摘要

本研究以氫氧化鋁(ATH)結合奈米黏土(Clay)作為聚乳酸(PLA)的無鹵素阻燃劑，藉由微型雙螺桿混練機製備聚乳酸/氫氧化鋁/奈米黏土之阻燃性複合材料。首先利用XRD、SEM及TEM來觀察複合材料之混合結構型態，進一步檢測複合材料之LOI及UL-94等耐燃性質，以及對熱穩定性、熱裂解活化能及機械性質作詳細的分析。結果顯示，奈米黏土經混練後於基材中已經呈現插層及脫層的型態。隨著奈米黏土取代氫氧化鋁含量的增加，能有效的提升複合材料之LOI值及UL-94等級，並且發現藉由奈米黏土之添加可以有效改善PLA/ATH複材之機械性質。所有複合材料中，以PLA：ATH：Clay重量比為50：45：5之複合材料阻燃效果最好，LOI可達到42，遠高於純PLA之20.5，阻燃等級也能達到UL-94規範之V-0等級，且沒有垂滴現象或引燃棉花。

關鍵字

微型雙螺桿混練機 ； 聚乳酸 ； 奈米黏土 ； 阻燃性複合材料 ； 限氧指數

並列摘要

Polylactide (PLA) composites with aluminum hydroxide (ATH) and montmorillonite (Clay30B) were prepared via direct melting compounding using a twin-screw micro extruder. It was found that the modified clays were either intercalated and or exfoliated in the matrix observed by XRD analysis and TEM micrographs. The limiting oxygen index, LOI, of the PLA composite can be increased from 20.5 for the PLA without fillers to 36 for that with 50 wt% of ATH, and the LOI can be further raised to 42 for the PLA composite with 5 wt% of clays and 45 wt% of ATH. The V-0 rating of the PLA nanocomposite with 39 wt% of ATH and 1% of montmorillonite was verified by UL-94 testing. The thermal degradation of the nanocomposite was further evaluated by thermogravimetric analysis and Ozawa method. It was found that the activation energy of degradation of the PLA nanocomposite under air is higher than that without addition of ATH and montmorillonite. The tensile strength of the PLA composite contains ATH, at PLA:ATH=60:40 in weight, is about 45 MPa, it can be increased to 52 MPa with partial substitute of montmorillonite at PLA:ATH:clay=50:37:3.

並列關鍵字

twin-screw micro extruder ； flame retardance ； polylactide ； montmorillonite ； limiting oxygen index

參考文獻

[1] Vink, E.T.H., Rábago, K.R., Glassner, D.A. & Gruber, P.R. 2003, "Applications of life cycle assessment to NatureWorks™ polylactide (PLA) production", Polymer Degradation and Stability, vol. 80, no. 3, pp. 403-419.

[2] Réti, C., Casetta, M., Duquesne, S., Bourbigot, S. & Delobel, R. 2008, "Flammability properties of intumescent PLA including starch and lignin", Polymers for Advanced Technologies, vol. 19, no. 6, pp. 628-635.

[3] Yanagisawa, T., Kiuchi, Y. & Iji, M. 2009, "Enhanced flame retardancy of polylactic acid with aluminum tri-hydroxide and phenolic resins", Kobunshi Ronbunshu, vol. 66, no. 2, pp. 49-54.

[4] Hornsby, P.R. 1994, "Application of magnesium hydroxide as a fire retardant and smoke-suppressing additive for polymers", Fire and Materials, vol. 18, no. 5, pp. 269-276.

[7] Gross, R.A. & Kalra, B. 2002, "Biodegradable polymers for the environment", Science, vol. 297, no. 5582, pp. 803.