- 學位論文
Nylon 6/6T及Nylon 66/6T共聚合物之結晶行為研究
A Study of Crystallization Behavior in Nylon 6/6T and Nylon 66/6T copolymers
摘要
本實驗主要分為兩個研究方向:以尼龍6與尼龍66分別作為基質，改變不同含量的尼龍6T共聚合物，並與基質尼龍6及尼龍66比較在不同等溫結晶溫度與不同降溫速率所完成之結晶熱力學、結晶動力學性質。 首先利用微差掃描熱卡計(DSC)將不同比例(3 mole%、5 mole%、7 mole%、10 mole %)的尼龍6T之尼龍6/6T於不同等溫結晶溫度(Tc)下結晶，根據Hoffman-Weeks方程式計算得到之平衡熔點(Tm°)，發現隨著尼龍6T含量增加，其平衡熔點(Tm°)會下降。再將樣品的結晶放熱曲線利用Avrami方程式加以分析，可得到樣品之Avrami指數(n)及結晶速率常數(k)，而結晶速率常數(k)會隨著等溫結晶溫度(Tc)的上升而下降，由此可證明結晶的成核成長機制。且隨著尼龍6T含量達到7mole%時，其結晶速率常數(k)有明顯降低趨勢。接著利用Lauritizen-Hoffman方程式可得到樣品之RegimeIII轉換成RegimeII臨界溫度，發現隨著尼龍6T含量增加，其臨界溫度隨之降低。並在WAXD圖譜中，得知尼龍6/6T-7mole%及尼龍6/6T-10mole %，有明顯的α晶型與γ晶型共同存在。 第二部份探討不同比例(5 mole%、10 mole%、15 mole%、20 mole%、30 mole%)尼龍6T之尼龍66/6T在不同等溫結晶溫度下結晶後，其根據Hoffman-Weeks方程式計算得之平衡熔點(Tm°)和Avrami方程式計算所得的Avrami指數(n)及結晶速率常數(k)與利用Lauritizen-Hoffman方程式可得到樣品之RegimeIII轉換成RegimeII臨界溫度，在與尼龍66比較之下都略為相同。而在WAXD圖譜中，在相同溫度下結晶所測得之晶型並未有明顯變化。
並列摘要
In this study, there were two topics based on the homopolymer Nylon 6 and Nylon 66 respectively. Crystallization kinetics of the homopolymer and copolymers both have been isothermally and non-isothermally investigated by different scanning calorimetry (DSC) and crystalline microstructure were studied by X-ray diffraction (WAXD). The equilibrium melting point was obtained using the Hoffman-Weeks method. The results show that the equilibrium melting point of Nylon 6/6T was decreased with an increasing Nylon 6T content in Nylon 6. With Avrami analysis, the crystallization rate (k) increased when the temperature increased. And the crystallization rate constant for Nylon 6 and Nylon 6/6T were evaluated. As the Nylon 6T content was reached to 7 mole% the crystallization rate constant was decreased rapidly. The transition temperature between Regime III and Regime II, obtained using the Lauritizen-Hoffman method, was found to be lower for Nylon 6/6T copolymer than the matrix Nylon 6. With WAXD, the model specimens were found to contain α form and γ form in Nylon 6/6T-7% and Nylon 6/6T-10%. Secondly the other system Nylon 66 and Nylon 66/6T, it was found that not only the equilibrium melting point and the crystallization rate (k) but also the transition temperature between Regime III and Regime II, which were similar to Nylon 66. The WAXD patterns were found to be unchanged.