Crystallization kinetics of PLLA-PEG copolymer/Clay

• Main Authors: Cheng-Chan Chuang, 莊成展
• Other Authors: Ph D. Wen- Hui Chiu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/43489424642285147388

碩士 === 萬能科技大學 === 工程科技研究所 === 98 === In this study, useing crystallization kinetics equation to discuss crystallization behavior model of PLLA-PEG copolymers (PEG,M ̅n= 200,1000,2000) nanocomposites (add montmorillonite (MMT)—Clay). Quaternary ammonium salts was used to expand the d-space (Å) of MMT. Also, utilizing“intercalation method from solution”will enable the MMT to even distribute into PLLA-PEG copolymers. The result of organic modification of MMT was observed by WXRD (Wide-Angle X-ray Diffraction) and TEM (Transmission Electron Microscope), the result shows that MMT evenly dispersed in the PLLA-PEG copolymers. The crystallization behavior was observed by DSC (Differential Scanning Calorimeter) and WXRD, using Arvami、Arrhenius and Hoffman-Weeks equation to explain the crystalline growth change of the PLLA-PEG copolymer composites after adding different proportions of MMT, as the increasing amount of the MMT, the model of the growth dimentionality ( n ) from a three-dimension and a one-dimension change to a two-dimension growth model. On the other hand, because amount of MMT increase will cause the k (overall crystallization rate) value to be smaller, the Ea value also changes to smaller. PEG segment length increase the growth dimentionality (n) of PLLA-PEG copolymers nanocomposites will approach two-dimension, and the crystallization rate will change quicker, Ea will change to lower, and Tm will elevate. Because PEG segment length increases causes crystalline growth space fill-out, but causes the crystalline easily to grow.