以奈米無機層材包覆二氧化矽並加以雙螺桿微混練法製備新型聚乙烯奈米複材與性質探討

Study on the Preparation and Characterization of Polyethylene Nanocomposites by Microcompounding Process with Mg-Al-LDH coated on SiO2

何紹禮(Shao-Li Ho)

指導教授 ： 蔡宗燕

中原大學/理學院/化學研究所/碩士(2019年)

https://doi.org/10.6840/cycu201900814

摘要

本研究利用高壓水熱共沉澱法，將人工合成鎂鋁層狀雙氫氧化物(Mg-Al-LDH)包覆於先行以溶膠-凝膠法自行合成之球形二氧化矽(SiO2)表面，並利用雙螺桿微混練機以兩種不同相容劑與線性低密度聚乙烯(LLDPE)進行熔融混練製備奈米級複合材料，再以熱壓機製備薄膜試片進行下列性質評估。以廣角X-光繞射分析儀(WXRD)及穿透式電子顯微鏡(TEM)鑑定無機層材在奈米複材中的分散性。以熱重分析儀(TGA)與示差掃描量熱儀(DSC)檢測複材之熱穩定性、熔點、再結晶溫度與結晶度的變化。以動態機械分析儀(DMA)與萬能拉伸試驗機(MTS)測量儲存模數及最大拉伸應力。以紫外-可見光譜儀(UV-Vis)了解其薄膜對可見光及紫外光UVA、UVB之穿透與阻隔效果，以氣體滲透分析儀(GPA)鑑定奈米複材對氣體的阻隔性，以接觸角量測與吸水率檢測奈米複材之表面親疏水性，最後以熱機械分析儀(TMA)量測奈米複材之尺寸安定性。結果顯示，在相容劑PEgMA系統下添加SiO2@Mg-Al-3 phr之聚乙烯複合材料，在熱穩定性提升3 ℃，熱結晶溫度上升4 ℃；在機械性質的儲存模數上升25.12 %，最大拉伸應力上升3 %；尺寸安定性方面從429.891 ppm降低至154.237 ppm。在相容劑EVA系統下添加SiO2@Mg-Al-3 phr之聚乙烯奈米複材，在紫外光波段UVA下降12.52 %、UVB下降7.66 %；在親水性方面接觸角由101.77 o下降至81.63 o；添加SiO2@Mg-Al-2 phr在氧氣阻隔性提升了2.5倍，在氮氣阻隔性提升了1.76倍。
由上述可知，以不同相容劑(PEgMA與EVA)添加入聚乙烯，與無機層材進行共熔融混練加工，會導致奈米複材不同性能的提升，將於本文中探討之。

關鍵字

聚乙烯 ； 層狀雙氫氧化物 ； 二氧化矽 ； 奈米複材 ； 包裝材料

並列摘要

In this work , the artificial Mg-Al-LDH was prepared by hydrothermal coprecipitated synthesis and coated on the spherical surface of SiO2 which made by sol-gel process, also to utilize the twin-screw micro-compound process and linear low density polyethylene (LLDPE) to conduct melting compounding preparation for nanocomposite material , after that use a film test piece was prepared by a hot press to evaluate the following properties.
Dispersion morphology of the polyethylene nanocomposites could be identified by wide-angle X-ray diffraction analyzer (WXRD), transmission electron microscopy (TEM). Thermal stability, melting point, recrystallization temperature and the degree of crystallinity could be determined by the thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC). Mechanical properties measured by the dynamic mechanical analyzer (DMA) and tensile test. Optical properties measured by UV-vis spectrometers (UV-Visible). The gas barrier properties, contact angle measurement, and the dimensional stability is also studied in this work. The results show that PE/PEgMA/SiO2@Mg-Al-3 phr performed the enhancement of the thermal stability up to 3 ℃, recrystallization temperature up to 4 ℃. The storage modulus increased by 25.12% and the tensile stress increased by 3%, and the dimensional stability has decreased from 429.891 ppm to 154.237 ppm.
In sample PE/EVA/SiO2@Mg-Al-3 phr, the transmittance of UVA decreased form 16.94 % to 4.42 % and the UVB from 8.82 % to 1.16 % in the ultraviolet range. The contact angle of the sample of PE/EVA/SiO2@Mg-Al-3 phr decreased from 101.77 o to 81.63 o in terms of more hydrophilicity; The addition of SiO2@Mg-Al-2 phr improved the oxygen barrier improvement factor from 1.27 to 2.50 and the nitrogen barrier improvement factor (BIF) from 1.16 to 1.76.
According to above, results the different compatibilizer (PEgMA & EVA) were applied to PE separately and inorganic layer materials were conducted by the twin-screw micro-compounding process. The different properties of nanocomposite materials have been improved and investigated in this work.

並列關鍵字

Polyethylene ； LDH ； SiO2 ； Nanocomposites ； Packaging Materials

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