綿セルロース布の弱酸性あるいは中性条件下でのTEMPO触媒酸化

抄録

Cotton fabrics were oxidized with TEMPO/NaClO/NaClO₂ or 4‐acetamido‐TEMPO/NaClO/NaClO₂ system in water at pH 3.8 or 6.8 and 40-80℃ for 0-120 min. As references, cotton fabrics were oxidized with TEMPO/NaBr/NaClO system in water at pH 10 and room temperature for 0-45 min. In all cases, the higher the carboxylate content of the oxidized cotton fabric, the lower its viscosity‐average degree of polymerization (DP_v). However, the oxidation at pH 3.8 and 6.8 gave cotton fabrics with higher DP_v values at carboxylate contents > 0.3 mmol/g, compared to those prepared at pH 10. When the cotton fabrics oxidized with 4‐acetamido‐TEMPO/NaClO/NaClO₂ system in water at pH 3.8 or 6.8 were heated at 105℃ for 2 h, clear whiteness reductions were observed, a part of which may have been caused by thermal degradation of 4‐acetamido‐TEMPO‐related compounds physically adsorbing on the oxidized cotton fabrics and slightly remaining in them even after repeated washing with water. When ethylene glycol, gluconic acid or glucose was directly added to the aqueous solution containing the cotton fabric after the oxidation, the oxidized cotton fabrics had relatively low whiteness reduction and low bending resistance (or better softness for clothes) even after heating at 105℃ for 2 h. Thus, the TEMPO‐ or 4‐acetamido‐TEMPO‐mediated oxidation in water at pH 3.8 or 6.8 may be applicable to chemical modification of cotton fabrics to be used as clothes for functionalized underwear.