Abstract
Abstract This thesis contains investigated the microstructure of comb-like and star-like polymer complexes. The comb-like complexes were created through complexation of poly(ethylene oxide) (PEO) and dodecylbenzenesulfonic acid (DBSA). Hydrogen-bonding interaction between PEO and DBSA was observed from the result of fourier transform infrared spectrometry (FTIR), the birefringence pattern viewed under polarized optical microscopy (POM) showed that PEO(DBSA)x complexes exhibited mesomorphic phases. Small angle X-ray scatting (SAXS) and wide angle X-ray diffraction (WAXD) revealed the microphase separated lamellar structure in the complexes, where the POM chains were inserted into the DBSA layers and were highly-stretched. Since the PEO chains were confined in the DBSA lamella, the crystallization of PEO was completely prohibited except for very degree of complexation (x=0.1). The mesophase isotropization temperatures of the complexes were higher than that of DBSA. In other words, complexes with PEO had improved the stability of mesophase. The rate of mesophase formation in the complexes was much faster than that of pure DBSA. This was attributed to the presence of local concentration fluctuation in the melt of the complexes. The second part of the thesis investigated the star-like polymer complexes. We report the creation of star-like chain architecture through complexation of a mono-amino terminated poly(ethylene oxide) (PEO-NH2) with a macrocyclic compound, 4-sulfonic calix[n]arene(n=4 and 8) (SCA-n). The complexes were prepared in aqueous solution to render proton transfer from the sulfonic acid groups in SCA-n to the amino groups in PEO-NH2, and thereby generated 4- and 8-arm star-like complexes with the PEO arms attached to the SCA-n cores via ionic bonding. Formation of the star-like complexes was verified by titration, solubility test, and dilute solution viscometry. The intrinsic viscosities ([h]) of the complexes in toluene were 60% higher than that of neat PEO-NH2, showing that the star structure retained in nonpolar solvents. On the other hand, PEO arms dissociated from the cores in water, so that the complexes and neat PEO-NH2 displayed similar [h]. The star-like complexes showed a SAXS peak associated with the core-core correlation in the melt with the inter-core distance of 7.3 nm. The concentration fluctuation in the melt was completely destroyed upon the crystallization of PEO arms. In the semicrystalline state, the SCA-n cores were excluded from the crystal lattice and resided in the interlamellar amorphous regions. Measurements of the crystal thickness by SAXS indicated that the crystals were once- and twice-folded in neat PEO-NH2 and the complexes crystallized at 40℃ respectively. The growth rate of the star-like complexes was slower than that of pure PEO, and the effect magnified as the number of arms increased.