- 學位論文
射出成型尼龍6奈米複合材料機械性質之探討
Study on Mechan6-Clay ical Properties of Injection Molded Nylon Nanocomposites
摘要
中文摘要 奈米複合材料的研究是近幾年來最熱門的科技，其具有的高剛性、低吸水性等特性可應用於許多射出產品，因此探討射出製程技術對奈米複合材料產品性質的影響有助於產品的廣泛應用。為了解相關物性與加工性質，我們選定尼龍6及尼龍6/氟化雲母奈米複合材料，利用毛細管流變儀及PVT量測儀來探討黏度和比容變化並改變射出製程參數:料溫、模溫、射速及保壓壓力來量測機械性質。另一方面，為了探討材料內部結構變化，分別使用X-ray、示差熱掃描分析儀(DSC)、偏光顯微鏡和掃描式電子顯微鏡(SEM)來印證微結構並討論與機械性質的相關性。 從研究結果得知，在相同剪切率下，尼龍6奈米複合材料的黏度比尼龍6低。在PVT關係圖部份，尼龍6奈米複合材料在相同壓力曲線下，塑料從熔融溫度到凝固溫度，其比容變化比尼龍6小，這說明加入氟化雲母補強材能改善尼龍6流變性，使成品的尺寸安定性增加，收縮翹曲減小，加工成型性變好。在機械性質方面，尼龍6奈米複合材料的機械強度大於尼龍6，而製程參數改變以模溫、射速及保壓壓力對二種材料結晶程度有相同趨勢影響，但料溫改變則呈現相反趨勢。 DSC測試結果印證，不同射出製程參數會改變相同材料的結晶程度，而結晶程度愈高，機械強度愈好。從偏光顯微鏡觀察結果發現，尼龍6奈米複合材料的結晶尺寸比尼龍6小，而從SEM測試觀察結果發現，奈米複合材料試片破壞斷面平整，由此可知加入氟化雲母補強材會增加材料拉伸強度和抗彎強度但衝擊強度則變差。
並列摘要
Abstract The research of nano-composite material becomes one of the most popular technology subject recently. This technology could be used widely in many injection molded parts because of its special characteristics such as high strength modules and high resistance to moisture absorption. Therefore, it is highly valued to understand the molded product properties of nano-composite and their influence form processing parameters during injection molding process. In this research, pure Nylon-6 material and Nylon-6/fluorine mica nano-composite material were selected to carry out the following tests: · Viscosity and specific volume behavior measurements by capillary rheometer and P-V-T instruments · Mechanical properties/modules measurement for injection molded parts molded under various process parameters including melting temperature, mold temperature, injection speed, and holding pressure. · Microstructure studies of the molded parts by X-ray, DSC, polarized-light microscopy and SEM. The results show that the Nylon-6/mica nano-composite material has lower viscosity and specific volume than those of the pure Nylon-6 material. This indicates that the Nylon-6/mica has an improved flowing property and dimension stabilization. The Nylon-6/mica nano-composite material has higher strength than the pure Nylon-6 material. Increases in mold temperature, injection speed and holding pressure will increase the crystallization of nano-composite material leading to a higher mechanical strength. However, an increase in melt temperature results in an opposite trend on strength enhancement. The result of DSC measurement shows that the internal material crystallization varies with molding parameters. The higher the crystallization degree inside the molded nano-composite, the better the mechanical strengths. The observed results from polarized-light microscopy and SEM indicate that adding the mica into material decrease the size of the internal material crystallization structure which leads to an increasing of mechanical strengths.