Surface chemical and morphological properties of a blend containing semi-crystalline and amorphous polymers studied with ToF-SIMS, XPS and AFM

The polymers BA-C8 and 6FBA-C8 were obtained by condensation polymerization of 1,8-dibromo-octane with bisphenol A and 4,4′-(hexafluoroisopropylidene)diphenol, respectively. A blend (BA-C8/6FBA-C8 (80/20)) containing 80 wt% of BA-C8 and 20 wt% 6FBA-C8 was prepared. Only one glass transition temperature was detected using a differential scanning calorimeter, suggesting that the blend is miscible. The surface chemical and morphological properties of the blend were studied as BA-C8 crystallized using atomic force microscopy, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry and contact angle measurements. The results of the surface analyses showed that the surface of the blend was found to be enriched in the 6FBA-C8 polymer, especially at the crystalline regions. The crystalline regions were found to be raised above the amorphous regions. Surface segregation and crystallization were the two main factors that contributed to the changes in the chemical composition and morphology of the surface.