Characterisation of cryogenic electrospinning process : evaluation of cryogenic processing on polymer properties

• Main Author: Lim, Chao Ching.
• Other Authors: Chian Kerm Sin
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Nanotechnology
• Online Access: http://hdl.handle.net/10356/54112
• Institution: Nanyang Technological University

Recent advancement in the fields of tissue engineering has led to an increase in focus on the usage of biomaterials to enhance or replace certain biological functions, especially biodegradable polymers. One of the techniques involves cryogenic electro spinning of PLA (polylactic acid) to form scaffolds that mimic the natural extra cellular matrix (ECM) to support the growth of tissue cells. This study aim to discover is the effect of the rate-of-cooling on PLA polymers. After freezing the PLA solution using different coolants, the microstructures of the fibres formed are compared and to determine if faster rate of cooling will result in a weaker structure based on DSC, SEM and X-ray analysis. Hydrolytic degradation of the PLA polymer with respect to time will also be included in this study. From the experiments, percentage crystallinity of the PLA polymer decreased from 58% to around 44% in the cryogenic processed specimens. Melting temperatures and glass transition temperatures are also lower as compared to specimen evaporated at room temperature. It appears that cryogenic processing of polylactic acid will lead to a decrease in crystallinity and as a result, suffer a loss of material strength. It is found that quenching by liquid nitrogen as compared to dry ice is unnecessary as the differences in the effects are negligible.