Kinetic evaluation of the size-dependent decomposition performance of solvent-free microcellular polylactic acid foams  

作　　者：GUO GePu MA QingYu WANG Fang ZHAO Bo ZHANG Dong 

机构地区：[1]Key Laboratory of Optoelectronics of Jiangsu Province,School of Physics and Technology,Nanjing Normal University,Nanjing 210046,China [2]Center of Analysis and Testing,Nanjing Normal University,Nanjing 210046,China [3]College of Chemistry and Materials Science,Nanjing Normal University,Nanjing 210046,China [4]Institute of Acoustics,Key Laboratory of Modern Acoustics,Ministry of Education,Nanjing University,Nanjing 210093,China

出　　处：《Chinese Science Bulletin》2012年第1期83-89,共7页

基　　金：supported by the National Basic Research Program of China(2011CB707900);the National Natural Science Foundation of China(10974098);the Natural Science Foundation of Jiangsu Province(BK2009407);the Doctoral Fund of the Ministry of Education of China(20093207120003)

摘　　要：A thermal gravimetric method is described for evaluating the kinetics of cell size-dependent decomposition and lifetime estima- tion for microcellular tissue engineering scaffolds made of biodegradable polylactic acid(PLA)foams.PLA foam cell sizes from 550 to 20?m were fabricated experimentally using a solvent-free solid-state foaming technique under saturation pressures from 1 to 5 MPa.The thermal properties of the PLA foams with respect to the cell sizes were measured using thermal gravimetric analy- sis in a nitrogen atmosphere and the activation energy and pre-exponential factor were derived to evaluate the decomposition ki- netics and estimate lifetime.It was found that small cell sizes can be achieved under high saturation pressures and that the thermal stability of PLA decreases after the fabrication process.The cell size-dependent thermal stability and degradation rate indicate that a PLA foam of larger cell sizes has a shorter degradation time,a few tenths that of the PLA raw material,at a temperature of 37°C. The results suggest that it is feasible to optimize fabrication parameters to obtain appropriate cell sizes and lifetimes that satisfy the application requirements for various organs.This study provides the basis for precise scaffold design and quantitative analysis of PLA foams in tissue engineering applications.A thermal gravimetric method is described for evaluating the kinetics of cell size-dependent decomposition and lifetime estimation for microcellular tissue engineering scaffolds made of biodegradable polylactic acid （PLA） foams. PLA foam cell sizes from 550 to 20 μm were fabricated experimentally using a solvent-free solid-state foaming technique under saturation pressures from 1 to 5 MPa. The thermal properties of the PLA foams with respect to the cell sizes were measured using thermal gravimetric analysis in a nitrogen atmosphere and the activation energy and pre-exponential factor were derived to evaluate the decomposition kinetics and estimate lifetime. It was found that small cell sizes can be achieved under high saturation pressures and that the thermal stability of PLA decreases after the fabrication process. The cell size-dependent thermal stability and degradation rate indicate that a PLA foam of larger cell sizes has a shorter degradation time, a few tenths that of the PLA raw material, at a temperature of 37℃ The results suggest that it is feasible to optimize fabrication parameters to obtain appropriate cell sizes and lifetimes that satisfy the application requirements for various organs. This study provides the basis for precise scaffold design and quantitative analysis of PLA foams in tissue engineering applications.

关 键 词：分解动力学 泡沫细胞 聚乳酸 无溶剂 热性能 评价 微孔 寿命估计 

分 类 号：TQ326.9[化学工程—合成树脂塑料工业] O631.22[理学—高分子化学]