Functional Finishing of Natural Fibers by Interfacial Graft Polycondensation

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09555295
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: 高分子構造・物性(含繊維)
• Research Institution: KYOTO UNIVERSITY
• Principal Investigator: MIYAMOTO Takeaki Kyoto Univ., Inst.Chem.Res., Assoc.Prof., 化学研究所, 教授 (60027050)
• Co-Investigator(Kenkyū-buntansha): ITO Hiraku Heian Jogakuin College, Prof., 生活学科, 教授 (20213077) ; DONKAI Nobuo Nigata Women's College, Prof., 生活科学科, 教授 (90237181) ; TSUJII Yoshinobu Kyoto Univ., Inst.Chem.Res., Instructor, 化学研究所, 助手 (00217308)
• Project Period (FY): 1997 – 1998
• Keywords: functional finishing / wool / cotton / interfacial / colored polymer / shrinkproofing / dyeing / water-repellency

Research Abstract

Summary
A new technique has been investigated for the functional finishing of natural fibers such as wool and cotton fibers. The principle of this technique is based on the formation of a thin, uniform, colored polymer film, e.g., poly(hexamethylene sebacamide) film, on the fiber surface by an interfacial polycondensation reaction. For wool, this technique may provide the simultaneous dyeing and shrinkproofing without damaging the hydrophobic nature of the fiber surface and for cotton, the dyeing, dimensional stability and water-repellency of fibers.
The process involves (i) immersion of fibers or fabrics in an aqueous solution of an aliphatic diamine containing reactive dye, surfactant and sodium hydroxide, (ii) padding to remove excess liquor, (iii) immersion in a solution of diacyl chloride in a water-immiscible solvent, (iv) padding to remove excess liquor, and (v) washing and drying. The reaction time takes place within a few minutes at room temperature. The surfactant is used to fa cilitate the wetting of fibers.
The results on wool fibers showed that (1) the finishing compresses an interfacial graft polymerization of wool fibers and is proved to be very effective as a method for rendering wool fibers shrinkproof, (2) the color shade and depth of the fibers can be arbitrarily controlled from pastel to deep colors by changing the dye and its amount, (3) the hydrophobic nature at the fiber surface can be maintained by controlling the alkyl lengths of diamine and /or diacyl chloride, (4) the light fastness of colored. polyamides depends on the kind of dyes, (5) similar functions can be rendered to the wool fibers by adding the dye in the water-immiscible solvent, i, e., in the second bath, but (6) the post-treatment of fibers, e.g., the post-treatment with formic acid which is a solvent for alphatic polyamides, is required to improve the effect of the above-mentioned finishes.
Preliminary trials on cotton fibers suggested that this technique is also effective not only as a method for pastel dyeing of cotton fibers, but also as a functional finishing for rendering cotton fibers or fabrics dimensional stability and water-repellency.