Jin Motoyanagi

A novel [60]fullerene-appended initiator for living cationic polymerization and its application to the synthesis of [60]fullerene-end-capped poly(vinyl ether)s

A new C60 derivative (C6060VE, {6}-1-[3-(2-vinyloxyethoxycarbonyl)propyl]-{5}-1-phenyl[5.6]C61) with a vinyl ether group was synthesized, and the potential ability of its TFA adduct (C6060VE-TFA, {6}-1-[3-{2-[1-(trifluoroacetoxy)ethoxy]-ethoxycarbonyl}propyl]-{5}-1-phenyl[5.6]C61) as a novel initiator for living cationic polymerization of vinyl ethers (VEs) was studied. It was found that the initiator afforded C60-end-capped polymers with well-controlled architecture, and the obtained polymer exhibited solvatochromism, indicating self-assembly in the media.

Self-Assembly Behavior of Amphiphilic C60-End-Capped Poly(vinyl ether)s in Water and Dissociation of the Aggregates by the Complexing of the C60 Moieties with Externally Added γ-Cyclodextrins

C60-end-capped polymers consisting of an amphiphilic poly(2-methoxyethyl vinyl ether) (PMOVE) main chain were synthesized by living cationic polymerization using a C60-functionalized initiator (C60VE-TFA) in the presence of EtAlCl2 as an activator and dioxane as an added base. The obtained polymers (C60-PMOVE) dissolved in a wide range of solvents including water and exhibited solvatochromism depending on the polarity of the media employed. This phenomenon was attributed to self-assembly in polar media due to hydrophobicity of the C60 moieties at the terminus of the amphiphilic polymer chain. Furthermore, the addition of γ-cyclodextrin (γ-CD), a strong host molecule for fullerenes, to the self-assembled system brought about the dissociation of the aggregates into molecularly dispersed free polymer chains. Titration of the aqueous solution of the self-assembly of C60-PMOVE with γ-CD indicated the possible formation of inclusion complexes of C60-PMOVE and γ-CD, and this binding process occurs in a positive cooperative manner.

Formation of Discrete Ladders and a Macroporous Xerogel Film by the Zipperlike Dimerization of Meso–Meso‐Linked Zinc(II) Porphyrin Arrays with Di(pyrid‐3‐yl)acetylene

Metal porphyrins assemble to form a supramolecular architecture with a characteristic structure and characteristic properties and functions upon complexation with appropriate ligands. However, there are few applications of these assembly processes to the construction of polymeric porphyrin arrays with useful functionalities. In this study, we found that meso-meso-linked Zn(II) porphyrin arrays underwent zipperlike dimerization upon complexation with di(pyrid-3-yl)acetylene (DPA) in chloroform to form discrete double-stranded porphyrin ladders. Similarly, the assembly of poly(zinc(II) porphyrinylene) with DPA gave a thermoresponsive gel, whose three-dimensional network structure was so strong that a macroporous xerogel film was obtained.

Surface Modification of a PET Substrate Through the Controlled Graft Polymerization and Application to the PET ⁄ Apatite Hybrids Formation

Organic ⁄ inorganic hybrid materials have attracted much attention because they are capable of combining the characteristic features of both organic and inorganic substances. This study aims to fabricate novel hybrids consisting of PET and apatite as components and to improve the mechanical properties of the hybrid through designing the interfacial structure between PET and an apatite layer. To this end, a PET substrate was modified with graft polymer chains bearing Si(OCH3)3 functions through the surface-initiated atom transfer radical polymerization (ATRP) and then subjected to the hybrid formation with apatite by a process mimicking biomineralization. This process was achieved by soaking the surface-modified PET substrate in a simulated body fluid (SBF) with ion concentrations nearly equal to human blood plasma. In this study, the PET substrate was modified with hyperbranched graft polymers with pendant Si(OCH3)3 functions, then coated with a calcium silicate gel and finally soaked in SBF for 3d to form the target PET ⁄ apatite hybrid. To evaluate the effects of the surface modification with grafted polymers on the mechanical properties of the PET ⁄ apatite hybrid, the interfacial bond strength between the PET substrate and the apatite layer was estimated by a peel test using a commercial adhesive tape.