生物可分解性聚乳酸與JeffamineR聚醚胺改質多壁奈米碳管複合材料之製備及其性質探討

Preparation and Properties of Biodegradable Poly(lactic acid)/JeffamineR polyetheramine Modified Multi-Walled Carbon Nanotube Nanocomposites

何維軒(Wei-Syuan He)

指導教授 ： 石燕鳳

朝陽科技大學/理工學院/應用化學系碩士在職專班/碩士(2012年)

摘要

本研究是將聚乳酸 (Poly(lactic acid)，PLA) 和多壁奈米碳管 (Multi-walled carbon nanotubes，MWCNTs) 藉由熔融混煉 (Melt-blending) 的方式進行混摻，而獲得奈米複合材料。為了增進多壁奈米碳管在複合材料中的分散性，首先將多壁奈米碳管加入HNO3溶液中，進行酸化，使碳管表面帶有羧機 (-COOH) 的官能基，然後再分別加入JeffamineR Polyetheramine系列中的M600 (EO/PO = 1/9)、M1000 (EO/PO = 19/3)、M2005 (EO/PO = 6/29)、M2070 (EO/PO = 33/10)，在溫和的條件下，藉由N，N，- 二環己基碳二亞胺 (N，N，-dicyclohexyl-carbodiimide，DCC) 脫水劑脫水，使碳管和JeffamineR Polyetheramine之間產生醯胺鍵的化學鍵結。再利用簡單的熔融混煉方式製備PLA/MWCNTs奈米複合材料，並進一步對於複合材料的熱性質、機械性質及導電性，和使用不同分子量及EO/PO比之改質劑對碳管改質後，其分別對複合材料的影響進行探討。
結果顯示，使用低分子量的JeffamineR Polyetheramine改質劑的改質碳管 (MWCNT-M600與MWCNT-M1000)，可以有效的改善複合材料的熱性質，而使用高分子量的JeffamineR Polyetheramine改質劑的改質碳管(MWCNT-M2005與MWCNT-M2070)，則可以均勻分散在
PLA中，有效的改善複合材料的機械性質及導電性質。當添加3.0 wt%的MWCNT-M600之複合材料，5 wt%重量損失之熱裂解溫度較純聚乳酸提升7.2℃。機械性質和導電性質方面，當添加3.0 wt%的MWCNT-M2070之複合材料，在40℃下其儲存模數和損失模數分別提升了79.0%及86.4%，而Tg也從原本的71℃提升至73℃。在導電部份，PLA的表面電阻為1.27×1012 Ω/□，而添加3.0 wt%的MWCNT-M2070之複合材料，其表面電阻為8.30×10-3 Ω/□，具有抗靜電的效果，甚至達到靜電消散或抗EMI的效果，未來將可以應用在電子相關產品上。

關鍵字

生物可分解 ； 聚乳酸 ； 聚醚胺 ； 多壁奈米碳管 ； 奈米複合材料 ； 熔融混煉

並列摘要

In this study, poly(lactic acid)/multi-walled carbon nanotubes (PLA/MWCNTs) hybrids were prepared by a melt-blending method. In order to enhance the compatibility between PLA and MWCNTs, the surfaces of MWCNTs were chemically modified. MWCNTs were first pre-treated using acid solution (HNO3) to obtain functionalized carboxylic groups. Subsequently, JeffamineR Polyetheramines (M600 (EO/PO = 1/9), M1000 (EO/PO = 19/3), M2005 (EO/PO = 6/29) and M2070 (EO/PO = 33/10) were grafted onto MWCNTs with the assistance of a dehydrating agent, N，N，-dicyclohexyl-carbodiimide (DCC), respectively. As a result, organically modified MWCNTs (MWCNT-M600, MWCNT-M1000, MWCNT-M2005 and MWCNT-M2070) were obtained. The PLA/MWCNTs nanocomposites were further prepared through the melt-blending method. Thermal behavior, mechanical properties, and conductivity of resultant PLA/MWCNTs composites were investigated. Moreover, the effects of different molecular weight and EO / PO ratio of JeffamineR Polyetheramines on the properties of modified carbon nanotubes and PLA composites were discussed.
The results show that low-molecular-weight JeffamineR Polyetheramine modified carbon nanotubes (MWCNT-M600 and MWCNT-M1000) can effectively improve the thermal properties of the PLA composites. On the other hand, high-molecular-weight JeffamineR Polyetheramine modified carbon nanotubes (MWCNT-M2005 and MWCNT-M2070) were uniformly dispersed in the PLA, and can effectively improve the mechanical properties, and conductivity of composite materials. With the addition of 3.0 wt% of MWCNT-M600, Td of the nanocomposite was 7.2℃ higher than that of the pristine PLA sample. With the addition of 3.0 wt% of MWCNT-M2070, the increments of E’ and E” of the nanocomposite at 40℃ was 79.0% and 86.4%. In the aspect of conductivity, the surface resistivity decreased form 1.27×1012 Ω/□ for neat PLA to 8.30×10-3 Ω/□ for the nanocomposites with 3.0 wt% of MWCNT-M2070. Such PLA/MWCNT-M2070 nanocomposites are highly efficient for anti-static purpose, even electrostatic discharge and EMI shielding, which can be applied in electronic materials.

並列關鍵字

multi-walled carbon nanotubes ； polyetheramine ； poly(lactic acid) ； melt-blending method ； nanocomposites ； biodegradable

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