Journal of Fiber Science and Technology
Online ISSN : 2189-7654
ISSN-L : 2189-7654
Current issue
Displaying 1-2 of 2 articles from this issue
Transaction
  • Yu Osaki, Kazuki Nawa, Yoko Kusaka, Toyohiro Otani, Shinichi Yusa
    Article type: Transaction
    2025 Volume 81 Issue 1 Pages 1-10
    Published: January 15, 2025
    Released on J-STAGE: January 17, 2025
    JOURNAL FREE ACCESS

    Reversible addition-fragmentation chain transfer (RAFT) controlled radical polymerization using trithiocarbonate compounds which can be used a wide range of applications as a chain transfer agent (CTA). We investigated the effects of solvent and feed ratio of monomer/CTA on polymerization using 4-cyano-4-((dodecylsulfanyl-thiocarbonyl) sulfanyl) pentanoic acid (Rtt-05) as a trithiocarbonate CTA. Methyl methacrylate (MMA) was polymerized using Rtt-05 in various solvents. Number-average molecular weight (Mn) of obtained poly(methyl methacrylate) (PMMA) was close to the theoretical value, and molecular weight distribution (Mw/Mn) was narrow (= 1.27). RAFT polymerization of MMA was controlled with different feed molar ratio ([MMA]/[Rtt-05]) of MMA and Rtt-05 from 100 to 1,000. Random copolymerization with the combinations of MMA/methyl acrylate (MA) and MMA/styrene (St) using Rtt-05 can be controlled. The Mw/Mn values of the obtained random copolymers were less than 1.23. Block copolymers were prepared via RAFT polymerization using Rtt-05. When diblock copolymers (PMMA-b-PSt and PMMA-b-PMA) composed of PMMA/polystyrene (PSt) and PMMA/poly(methyl acrylate) (PMA) were prepared using PMMA as a macro CTA, the polymerization was well controlled with narrow Mw/Mn. On the other hand, block copolymerization of MMA using PSt and PMA macro-CTAs, the copolymerization could not be controlled with broad Mw/Mn.

    Download PDF (2023K)
Technical Paper
  • Watarua Okumura, Akichika Nakashima
    Article type: Technical Paper
    2025 Volume 81 Issue 1 Pages 11-16
    Published: January 15, 2025
    Released on J-STAGE: January 17, 2025
    JOURNAL FREE ACCESS

    We wove textiles with different surface properties on the front and back sides of a twill weave and a satin weave using a needle loom with a Jacquard shedding mechanism. The textiles were evaluated to glossiness, to qmax, and to air permeability. Based on the results, we discussed to the mechanism by which the difference between the front and back surfaces of the textiles. The textiles, both twill and satin weave, showed markedly different glossiness Gs(60) on the front and back surfaces, confirming that the weaving of textiles with different surface properties on the front and back surfaces was possible. The qmax, which indicates cool touch feeling property, were higher on the front side than on the back side for both the twill and satin weave. The reason for we considered to be that the surface of the textiles with less unevenness had a larger contact area between the heat source plate and the textiles surface during the measurement. The amount of air Vair that passed through the textiles, which indicates air permeability, were higher when the back surface was used as the air inlet surface than when the front surface was used as the air inlet surface for both twill and satin weave. A simple cross-sectional morphology model was presented to investigate this factor, and we considered that the airflow from the front side has a component that flows toward the front side, whereas the airflow from the back-side flows through a funnel-shaped area, resulting in higher air permeability than the airflow from the front side. These results indicate the possibility of controlling cool touch feeling property and air permeability by using textiles with different surface properties on the front and back sides.

    Download PDF (7496K)
feedback
Top