以不同單體與合成方法對於聚對苯二甲酸乙二酯 - 無機層狀材料奈米複合材料之機械性質提升的研究

Development of Polyethylene terephthalate-Inorganic Layered Material Nanocomposites with Improved Mechanical Properties by Changing Monomer and Preparation Methods

布納卡(Naveen Bunekar)

指導教授 ： 蔡宗燕

中原大學/理學院/化學研究所/博士(2017年)

https://doi.org/10.6840/cycu201700740

摘要

層狀雙氫氧化物（LDH）與天然黏土為常見的無機層狀材料，本研究使用三種合成LDH(LiAl、MgAl、ZnAl-LDH)，並將對氨基苯磺酸(sufanilic acid)透過離子交換法改質插層於層間。 天然黏土則使用二甲基十八烷基[3-（三甲氧基甲矽烷基）丙基]氯化銨(DTSACl)和四乙氧基矽烷（TEOS）透過溶膠凝膠法將其改質。改質後的無機層狀材料以X-光繞射分析儀（XRD）觀察其層間距離的變化，以熱重分析儀（TGA）探討熱種損失和插層量的計算，以傅立葉紅外光譜分析儀（FT-IR）比較改質前後官能基的變化，最後通過掃描式電子顯微鏡（SEM）觀察LDH的表面形態和結構。
於本研究中，首先我們以融熔混練法法成功製備聚對苯二甲酸乙二醇（PET）/有機改質型層狀雙氫氧化物(Organo-LDH)奈米複合材料。試圖透過表面改質提高LiAl、MgAl和ZnAl LDHs與PET的相容性。在含有改質型LiAl-LDH的PET奈米複合材料中，在XRD的檢測中未觀察到來自LDH的（001）繞射峰，且藉由穿透式電子顯微鏡(TEM)發現改質型LDH以脫層分散(Exfoliation)的型態均勻分散於PET中。然而，含有改質型MgAl和ZnAl LDH的PET納米複合材料則出現較寬的(001)特徵峰，於TEM中發現LDH是以部分插層(Intercalation)且部分脫層的絮凝型態(Floculated morphology)分散。根據熱重分析證實，藉由添加不同類型與添加量的LDH，使PET /Organo-LDH奈米複合材料的熱穩定性顯著提高，亦可觀察到其儲存模數和阻氣性的顯著提升。
其次，將通過插層改質製備之ZnAl LDH-SAS與雙（2-羥乙基）對苯二甲酸酯（BHET）單體成功以原位聚合方式製備PET/Organo-ZnAl LDH奈米複合材料。為了提高PET與ZnAl LDH之間的相容性，將對氨基苯磺酸鈉(SAS)改質插層於LDH中。 XRD與TEM用於檢測填料的分散度和於奈米複合材料中的分散型態。經由差示掃描量熱儀（DSC）和TGA分析，與純PET樣品相比，PET/ZnAl LDH-SAS奈米複合材料樣品的結晶速率和熱降解溫度增強。結果表明，經過有機改質後的ZnAl LDH-SAS不僅提高了與PET之間相容性，也使得寡具物更容易進入ZnAl LDH-SAS層間，因此在聚合反應期間，聚合物分子鏈得以於LDH層間聚合，並探討此類新型PET奈米複合材料的氣體阻隔特性和機械性質。
最後，通過原位聚合法成功合成了PET / MgAl LDH-SAS與PET/CL120-DT納米複合材料。經由XRD和TEM觀察奈米複合材料的分散形態，由結果得知1.0wt％的MgAl LDH-SAS和CL120-DT PE奈米複合材料呈現部分插層與絮凝型態分散。從DSC分析可以得知，MgAl LDH-SAS和CL120-DT添加量並不影響奈米複合材料的熔融溫度（Tm）。在本研究中PE的MVTR值為49 g·m−2·d-1，該值與的文獻中相同，而PET / CL120-DT 0.5wt％和PET / MgAl LDH-SAS 0.5wt％奈米複合材料，其MVTR值分別為45和46 g·m−2·d-1。值得一提的是，一般來說，水蒸氣的傳播與奈米填料分散性相關，OTR範圍為128至88 cc/m2/day/atm，相比於對照組（90% RH）為109~86 g·m−2·d-1，另外，對於處理0.5 wt%奈米複合材料，對照物中OTR的最大降低為90％RH，並且與0.3 wt%樣品之間沒有顯著差異。於光學性質的探討中，相較於完全透明純PET薄膜，含有LDH或CL120奈米粒子的複合材料薄膜的穿透率稍微降低。

關鍵字

聚對苯二甲酸乙二酯 ； 無機層狀材料 ； 奈米複合材料

並列摘要

Layered double hydroxides (LDHs) and clay are common inorganic layered hydroxides. In this study, three types of synthetic LDHs used and modified with sufanilic acid by ion exchange method. A natural montmorillonite (CL120) modified with Dimethyloctadecyl [3- (trimethoxysilyl) propyl] ammonium chloride (DTSACl) and Tetraethyl orthosilicate (TEOS) by sol gel method. These modified and pure inorganic layered materials (LDHs, Clay) were investigated by using X-ray Diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR) to monitor the changes in the interlayer spacing, weight loss and functional groups of modified LDHs and CL120, respectively. The morphology and structures of LDH, and CL120 were observed by scanning electron microscope (SEM), while the amount of modifier intercalated into the LDH, and CL120 layers were calculated by TGA analysis.
In this report, we have been synthesized three kinds of polyethylene terephthalate / modified inorganic layered material nanocomposites. At first, polyethylene terephthalate / organomodified-layered double hydroxide (PET/organo-LDH) nanocomposites were successfully synthesized via a melt extrusion method. In an attempt to improve the compatibility with PET, and surface modified LiAl, MgAl and ZnAl LDHs. In PET nanocomposites containing SAS modified LDHs, the (00l) X-ray diffraction (XRD) peaks originating from organo-LDH were not observed, indicating that organomodified LDH layers were homogeneously dispersed within the PET matrix, which was also confirmed by TEM analysis. PET nanocomposites containing SAS modified LiAl, MgAl, and ZnAl LDH showed that organo-LDH was intercalated, flocculated and partially exfoliated morphologies, respectively. According to the TGA it was confirmed that the thermal stability of PET/organomodified-LDH nanocomposites significantly improved, depending on the type and loading content of organo-LDH compared to that of pure PET. PET nanocomposites substantial enhancement of the storage modulus and gas barrier properties were observed.
Secondly, PET/ZnAl LDH-SAS nanocomposites were prepared by intercalation, followed by in situ polymerization using Bis (2-hydroxyethyl) terephthalate (BHET) monomer. To enhance the compatibility between PET and the modified ZnAl LDH, the sodium salt of sulfanilic acid (SAS) had been previously intercalated in the LDH. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to detect the degree of dispersion of the filler and the type of the polymeric composites obtained. As identified by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), the crystallization rate and the thermal degradation temperature of the as-prepared PET nanocomposites sample were enhanced compared with the pure PET sample. The results indicated that the ZnAl LDH-SAS improves the interlayer compatibility between the PET and ZnAl LDH-SAS layers, thus making it easier for the oligomer to enter the gallery of ZnAl LDH-SAS layers. Hence, polymer chains can be intercalated between the LDH layers during the polymerization of the polymer matrix. The gas barriers and mechanical properties of these new types of PET nanocomposites were investigated.
Finally, PET/MgAl LDH-SAS or CL120-DT nanocomposites were successfully synthesized using Bis (2-hydroxyethyl) phthalate (BHEP) monomer by in situ polymerization method. Dispersion morphology of nanocomposites elevated by XRD and TEM, from these results it was confirmed that 1.0 wt% loaded PET/MgAl LDH-SAS and PET/CL120-DT nanocomposites were partially intercalated and aggregated morphology. From the DSC analysis, it is evidenced that regarding the effect of MgAl LDH-SAS and CL120-DT content on the melting temperatures (Tm) values of PET nanocomposites are virtually unchanged, regardless of MgAl LDH-SAS and CL120-DT loading. The extracted Moisture Vapor Transmission Rate (MVTR) value for pure PET was found to be 49 g·m−2·d-1. This value is in good accordance with the literature value for PET. For the nanocomposites PET/CL120-DT 0.5 wt% and PET/MgAl LDH-SAS 0.5 wt%, the MVTR values were 45 and 46 g·m−2·d−1, respectively. It is worth mentioning that in general, the transmission of the water vapor is strongly related to the nanofiller dispersion. The Oxygen Transmission Rate (OTR) was ranging from 128 to 88 cc/m2/day/atm whereas, the control recorded (90% RH) ranging from 109 to 86 cc/m2/day/atm. It was also observed that the maximum reduction in OTR over the control was 90% RH for the treatment 0.5 wt% clay loaded nanocomposites and there was no significant difference between the treatments 0.3 wt% loaded samples. The optical properties of PET composite films containing various amounts of inorganic nanoparticles are transparent. The transmittance was found in the hybrid film containing LDH or CL120 nanoparticles contents in the matrix, beyond which the transmittance was slightly decreased as compare to pure PET.

並列關鍵字

Polyethylene terepthalate ； Inorganic layered materials ； Nanocomposites

參考文獻

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