scispace - formally typeset
Search or ask a question
Author

Hiroharu Ikeda

Bio: Hiroharu Ikeda is an academic researcher from Kyoto University. The author has contributed to research in topics: Polymerization & Oxazoline. The author has an hindex of 12, co-authored 20 publications receiving 549 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this article, a white powder was found to be poly(N-formylethyleneimine, which was shown to be a crystalline polyethyleneimine by X-ray diffraction diagram (mp ca. 210°C).
Abstract: Pure unsubstituted 2-oxazoline (OXZ) was first prepared in good yields by modifying Wenker’s method.1 OXZ was found to polymerize by cationic catalyst in an aprotic polar solvent to give a solid polymer. The polymerization of OXZ in less-polar solvents gave polymer in much decreased yields. Lewis acids such as BF3OEt2 and SbF5, sulfonates, sulfate esters, mineral acids, and alkyl iodide were effective as the polymerization catalyst. But metal chlorides such as SnCl4 and SbCl5 were ineffective. The polymer was a white powder, which was soluble in water and insoluble in most organic solvents. The polymer was shown to be crystalline by X-ray diffraction diagram (mp ca. 210°C). The molecular structure of the polymer proved to be poly(N-formylethyleneimine) by NMR and IR spectra. Alkaline hydrolysis of poly-OXZ gave crystalline polyethyleneimine (mp 58.5°C).

60 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: A general overview of the preparation, characterization and theories of block copolymer micellar systems is presented in this paper, with examples of micelle formation in aqueous and organic medium are given for di-and triblock copolymers, as well as for more complex architectures.

1,856 citations

Journal ArticleDOI
TL;DR: Insight is given into strategies developed for PEI-based non-viral vectors to overcome intracellular obstacles, including the improvement of methods for polyplex preparation and the incorporation of endosomolytic agents or nuclear localization signals.

928 citations

Journal ArticleDOI
Owen W. Webster1
22 Feb 1991-Science
TL;DR: Living polymerization techniques can be used to achieve a high degree of control over polymer chain architecture, which results in polymers with widely diverse physical properties, even though they are made from readily available low-cost monomers.
Abstract: Living polymerization techniques can be used to achieve a high degree of control over polymer chain architecture. Examples of the type of polymers that can be synthesized include block copolymers, comb-shaped polymers, multiarmed polymers, ladder polymers, and cyclic polymers. This control of structure, in turn, results in polymers with widely diverse physical properties, even though they are made from readily available low-cost monomers.

698 citations

Journal ArticleDOI
TL;DR: In this article, the authors discuss the combinations of thermosensitive properties with other types of sensitivity, i.e., pH, light, magnetic field, solvent quality, etc., and their effects on the reversible self-assembly in aqueous copolymer solutions or on the hydrogel organization.

692 citations

Patent
02 Mar 1994
TL;DR: In this paper, a lipid-polymer conjugate for long-circulating liposomes is presented. But the conjugates do not include a vesicle-forming lipid having convalently attached to its polar head group, such as polyvinylpyrrolidone or polyaspartamide.
Abstract: A lipid-polymer conjugate for use in forming long-circulating liposomes is disclosed. The conjugate includes a vesicle-forming lipid having convalently attached to its polar head group, one of the polymers: polyvinylpyrrolidone, polyvinylmethylether, polyhydroxypropyl methacrylate, polyhydroxypropylmethacrylamide, polyhydroxyethyl acrylate, polymethacrylamide, polydimethylacrylamide, polymethyloxazoline, polyethyloxazoline, polyhydroxyethyloxazoline, polyhydroxypropyloxazoline, or polyaspartamide. A method for preparing liposomes containing the lipid-polymer conjugate is also disclosed.

404 citations