Structures and properties of polycarbonate-modified epoxies from two different blending processes

✍ Scribed by Trong-Ming Don; Chao-Hsien Yeh; J. P. Bell

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 292 KB
• Volume: 74
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19991205)74:10<2510::aid-app20>3.0.co;2-p

✦ Synopsis

It has been proved in our previous study that during the melt-blending of an epoxy oligomer based on the diglycidyl ether of bisphenol-A (DGEBA) with polycarbonate (PC) at 200°C, the secondary hydroxyl groups in the DGEBA react with the carbonate groups in PC through transesterification, resulting in degraded PC chains with phenolic end groups and also in PC/DGEBA copolymers. Yet, in the same study, it was found that the prereactions between DGEBA and PC can be minimized or eliminated if a solution-blending process was used. Therefore, it was expected that, after being cured with a curing agent, different epoxy-network structures should result as a consequence of the two different premixing processes of DGEBA and PC. In addition, we also expect that in the melt-blending process, the fracture toughness of epoxies should be increased due to the incorporation of ductile PC chains into the epoxy network. In this study, therefore, we attempted to examine and compare the structures and properties of PC-modified epoxies through these two different blending processes.