A polymer, BA-C8, was synthesized. The isothermal crystallization process was studied in-situ using atomic force microscopy (AFM) at room temperature. The birth of a spherulitic embryo and the development of a founding lamella were observed. Embryos appeared as 10-nm diameter dots. Some disappeared, while the stable ones grew in length, becoming founding lamellae. The founding lamella grew as long as over 1 μm before branching occurred. According to our observations, there is only one founding lamella for each spherulite. The growth rate of the lamellae was measured at three different temperatures and found to be relatively constant at this early stage in the formation of spherulites. The founding lamella developed into a lamellar sheaf through branching and splaying. Three routines we...[ Read more ]

A polymer, BA-C8, was synthesized. The isothermal crystallization process was studied in-situ using atomic force microscopy (AFM) at room temperature. The birth of a spherulitic embryo and the development of a founding lamella were observed. Embryos appeared as 10-nm diameter dots. Some disappeared, while the stable ones grew in length, becoming founding lamellae. The founding lamella grew as long as over 1 μm before branching occurred. According to our observations, there is only one founding lamella for each spherulite. The growth rate of the lamellae was measured at three different temperatures and found to be relatively constant at this early stage in the formation of spherulites. The founding lamella developed into a lamellar sheaf through branching and splaying. Three routines were observed for the formation of the spherulite eyes. Heterogeneous nucleation and crystallization were studied as well.

The polymers BA-C8 and 6FBA-C8 were obtained by condensation polymerization of 1,n-dibromo-octane with bisphenol A and 4,4'-(hexafluoroisopropylidene)diphenol, respectively. A blend (BA-C8/6FBA-C8 (80/20)) containing 80wt% of BA-C8 and 20wt% 6FBA-C8 was prepared. The surface chemical and morphological properties of the blend were studied as the BA-C8 polymer crystallized using atomic force microscopy, X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. Only one glass transition temperature was detected using a scanning differential calorimeter, suggesting that the blend is miscible. However, the surface of the blend was found to be enriched in the 6FBA-C8. 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. AFM and ToF-SIMS have been shown to be invaluable tools for polymer surface study.

Fluorocarbon-hydrocarbon microblock polymers -(CF₂)_n-(CH₂)_m- (n= 4, 6, 8; m= 6, 8, 10) were synthesized. X-ray photoelectron spectroscopic (XPS) spectra were collected for these polymers. The C1s peak of the carbon atoms of the hydrocarbon segments was set at 285.0eV as the binding energy reference. The binding energies of the carbon and fluorine atoms were analyzed.