Photochromic polymeric films were prepared by doping photochromic dye spironaphthooxazine into polymer resin gels such as polyurethane, vinyl copolymer, and copolymer of vinyl and nitorocellulose at different concentrations. All of the composite films show normal photochromism. The kinetics of the photochromism/decoloration in the films were quantified by fitting biexponential equations to their photochromic decay curves after irradiation. It was observed that the decoration process is faster in vinyl copolymer than that in the copolymer of vinyl and nitrocellulose and is the slowest in the case of polyurethane. The decoloration mechanisms of spironaphthooxazine in those polymeric matrixes have been discussed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jp905700s | DOI Listing |
Chemistry
December 2024
The University of Tokyo Graduate School of Engineering School of Engineering: Tokyo Daigaku Daigakuin Kogakukei Kenkyuka Kogakubu, Department of Applied Chemistry, 7-3-1 Hongo, Bunkyo-ku, 113-8656, Tokyo, JAPAN.
Two-dimensional (2D) polymer network monolayers with novel block architectures were fabricated via sequential copolymerization within a pillared-layer metal-organic framework (MOF) that served as the reaction template. The MOF provides a confined 2D nanospace, restricting the crosslinking copolymerization of vinyl monomers to two dimensions. Sequential crosslinking copolymerization of methyl methacrylate and styrene, regulated by the reversible addition-fragmentation chain transfer (RAFT) process, resulted in the formation of 2D block architectures with 'patchy' domains consisting of crosslinked poly(methyl methacrylate) and polystyrene segments.
View Article and Find Full Text PDFAAPS PharmSciTech
December 2024
Hebei Province Key Laboratory of Research and Development for Chinese Medicine, Chengde Medical University, Chengde, 067000, Hebei, China.
Glycyrrhetinic acid (GA) possesses various pharmacological effects, including anti-inflammatory, anti-tumor, and anti-viral properties. However, its clinical application is limited by poor solubility and low oral bioavailability. Polymers play a crucial role in pharmaceutical formulations, particularly as matrices in excipients to enhance the solubility, bioavailability, and stability of active pharmaceutical ingredients.
View Article and Find Full Text PDFJ Mater Chem B
December 2024
Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 1219 Zhongguan West Road, Zhenhai, Ningbo, Zhejiang, 315201, China.
Recent advances in medical plastics highlight the need for sustainable materials with desirable elastic properties. Traditional polyester elastomers have been used as alternatives to polyvinyl chloride (PVC) due to their biocompatibility and adjustable mechanical properties. However, these materials often lack the necessary stability and toughness for reliable medical applications.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada.
In this study, we proposed a novel technique to simultaneously enhance the oxygen barrier properties and stiffness of high-density polyethylene (HDPE) while preserving its ductility. By utilizing in situ nanofibrillation, fiber-in-fiber composites of an HDPE matrix and ethylene-vinyl alcohol (EVOH) nanofibers were fabricated. Due to the high interfacial tension between HDPE and EVOH, stemming from their differences in chemical structure and polarity, styrene/ethylene-butylene/styrene copolymer grafted with maleic anhydride (SEBS--MA) was used as a compatibilizer to improve the affinity between the two polymers.
View Article and Find Full Text PDFChem Commun (Camb)
December 2024
EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK.
Herein, we report the first synthesis of poly(ester--vinyl acetate) epoxide/anhydride ring-opening copolymerisation and reversible addition-fragmentation chain transfer polymerisation. This was achieved using simple, robust and bifunctional alkali metal carboxylates featuring a xanthate unit.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!