1—The Deposition of Polyacrylonitrile in Wool

Abstract

The properties of wool fibres and flannel containing internal deposits of polyacrylonitrile are examined. Such wools have considerably enhanced resistance to solvents such as peracetic acid-ammonium hydroxide or aqueous sodium sulphide, and show only a slight Allwörden reaction. The elastic properties of the fibres are virtually unaffected, although small increases or decreases in the work-to-stretch 30 per cent may be noted, depending on the biological type of the fibre. There is a slight improvement in the resistance to abrasion, and a considerable improvement in the resistance to milling shrinkage, which can be reduced to about 3 per cent, compared with 30 per cent for untreated wool, by the presence of about 20 per cent of polyacrylonitrile. A reduction in the regain is also found. The reasons for these alterations in properties are discussed, and it is suggested that chemical grafting of the Polyacrylonitrile to the wool may be partly responsible.