以雙螺桿微混煉熱塑性聚氨酯/黏土奈米複材之製備與性質研究

Study on the Preparation and Characterization of Thermoplastic Polyurethane/ Clay Nanocomposites by Twin Screw Microcompounding Process

陳維澤(Wei-Tse Chen)

指導教授 ： 蔡宗燕

中原大學/理學院/化學研究所/碩士(2021年)

https://doi.org/10.6840/cycu202100394

摘要

本研究選用天然蒙脫土，實驗室代號CL120和CL88之天然黏土，經椰油醯兩性基二丙酸二鈉(DisodiumCocoamphodipropionate, K2)進行表面改質反應，可有效將天然黏土的層間距離加大，使原本較親水性的黏土變為較親油性的表面，使改質型黏土與高分子的相容性提升，利用X光繞射儀(X-ray Diffractometer, XRD)檢測天然黏土改質後的層間距變化，以熱重分析儀(Thermogravimetric Analyzer, TGA)檢測改質型黏土中層間改質劑的插層量與熱穩定性，傅立葉轉換紅外線光譜儀(Fourier Transform Infrared Sepectromter, FT-IR)比對天然黏土和改質型黏土之有機與無機的官能基，證明改質劑是否成功插層於無機層材的層間，利用雷射粒徑分析儀(Laser Diffraction Particle Size Analyzer, LDS)檢測改質型黏土粒徑大小和界面電位(Zeta-potential)。
將改質後的層狀材料，利用微型雙螺桿熔融混煉機(Twin Screw Microcompounding)與熱塑性聚氨酯(Thermoplastic polyurethanes, TPU)熔融混煉製備奈米級複合材料，以熱壓方式製成薄膜並進行各性質檢測與探討，機械性質部分以萬能拉力試驗機(Tensile Testing Machine)、動態機械分析儀(Dynamic Mechanical Analyzer, DMA)和耐磨耗機(Abrasion Tester)分別檢測複材的拉伸強度、儲存模數和耐磨耗，從分析數據可得知，以樣品TPU-CL88-K2-1.5CEC-2phr最佳，拉伸強度從原本的275.0 kgf/cm2提升至329.9 kgf/cm2，提升54.9 kgf/cm2，儲存模數從原本的846 MPa提升至1411 MPa，提升565 MPa，磨耗900圈重量損失由原本的0.0275 g減少到0.0133 g，耐磨耗提升51.6 %。分散型態以X-ray繞射光譜分析儀式及穿透式電子顯微鏡觀察(Transmission Electron Microscope, TEM)，TPU-clay複材在XRD分析圖並沒有看到黏土的特徵峰，添加3 phr改質型黏土奈米複材在薄膜表面觀察到改質型奈米黏土分散不均勻導致團聚造成的小顆粒，添加1和2 phr改質型黏土奈米複材TEM圖為海型脫層分散。耐熱性質方面以熱重分析儀探討複材的熱裂解溫度，TPU-CL88-K2-1.5CEC-2phr複材T5d點從原本的293 ℃增加到332 ℃最佳，提升39 ℃。利用微差掃描熱分析儀(Differential Scanning Calorimetry, DSC)以及動態機械分析儀可得知樣品的玻璃轉換溫度，DSC方面，從分析數據可得知，以樣品TPU-CL88-K2-1.5CEC-2 phr複材的Tg點，從原本-27.1 ℃上升到-16.1 ℃，提升40 %最佳；DMA方面，樣品TPU-CL88-K2-1.5CEC-2phr複材的Tg點，從原本的-30.1 ℃上升到-20.6 ℃，提升31 %最佳。利用紫外光-可見光圖譜分析儀(Ultraviolet-Visible Spectrophotometer, UV-Visible)測量奈米複材薄膜的穿透度，紫外光波長320 nm穿透度以樣品TPU-CL88-1.5CEC-3phr複材最佳，從原本穿透度86.2 %下降到50.5 %，降低41.4 %。耐老化測試，複材在12小時紫外光照下取出並檢測拉伸強度，從檢測數據可得知，以樣品TPU-CL88-1.5CEC-2phr複材的耐老化表現最佳，拉伸強度衰退由原本的18 %降低至6.6 %，耐老化提升63 %。
本研究使用無溶劑環保方法製備奈米複材，利用微型雙螺桿微混煉機混煉改質型奈米黏土和熱塑性聚氨酯，有效提升熱塑性聚氨酯的機械性質、熱性質、耐磨性質以及耐老化性質，且在耐老化測試方面效果有明顯的提升，上述的特性使得熱塑性聚氨酯在產業上有更廣泛的應用。

關鍵字

雙螺桿微混煉 ； 熱塑性聚氨酯/黏土奈米複材

並列摘要

This study is to improve the mechanical, thermal, and resistance to ultraviolet properties of thermoplastic polyurethane/montmorillonite nanocomposites, prepared with organic modified clays by twin screw microcompounding process. Prstine sodium montmorillonite clay was modified by disodium cocoamphodipropionate (K2), via ion exchange to enhance the compatibility between the clay platelets and the thermoplastic polyurethane matrix. The characteristics of modified clays were identified by fourier transform infrared (FTIR) spectroscopy for the organic functional groups of the modified clays, X-ray diffraction (XRD) pattern for the d-spacing of the modified clays, thermogravimetric analyzer (TGA) for the real intercalant amount of the modified agent in the modified clays, laser diffraction particle size analyzer for the particle size and Zeta-potential of the modified clays.
Two types of modified inorganic layered materials, CL88-K2 and CL120-K2 were applied to prepare the TPU/clay nanocomposites by twin screw microcompounding process. The best improvement of the mechanical properties for the sample TPU-CL88-K2-1.5CEC-2phr, the tensile strength is increased 54.9 kgf/cm2, the storage modulus is increased 565 MPa and the resistance to abrasion is increased 51.6 %. The dispersion morphologies are characterized by XRD and TEM. The results show that TPU-CL88-K2-1.5CEC and TPU-CL120-K2-1.5CEC nanocomposites with 1 and 2 phr clay loading displayed exfoliated morphologies. The decomposition temperature (T5d) of TPU-CL88-K2 -1.5CEC-2phr is increased 39 ℃ from 293 ℃ to 332 ℃. The glass transition temperatures (Tg) are tested by DSC of TPU-CL88-K2-1.5CEC -2phr is increased 40 % from -27.1 ℃ to -16.1 ℃. The Tg tested by DMA of TPU-CL88-K2-1.5CEC-2phr is increased 31 % from -30.1 ℃ to -20.6 ℃. The UV transmittance of CL88-K2-1.5CEC-3phr is decline 41.4 % from 86.2 % to 50.5 % at 320 nm wavelength. The nanocomposites were under 300 W power UV light at 280~400 nm wavelength for 12 hours and tested tensile strength by tensile testing machine. The results show that TPU-CL88-K2-1.5CEC-2phr has the best UV resistance. The tensile strength decreased form 18 % to 6.6 %, UV resistance increased 63 %.
Therefore, the performance of TPU-clay nanocomposites have shown the great improvement in various properties, especially in anti-aging performance. These characteristics enable the nanocomposites to be more widely applied in the industry.

並列關鍵字

Thermoplastic Polyurethane/ Clay Nanocomposites ； Twin Screw Microcompounding

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