Objective measurement of hand properties of plasma pre-treated cotton fabrics subjected to flame-retardant finishing catalyzed by zinc oxide

In the present paper, flame resistance property is imparted to cotton fabrics by N-methylol dimethylphos-phonopropionamide (Pyrovatex CP New, FR), melamine resin (Knittex CHN, CL), phosphoric acid catalyst (PA), and ZnO/nano-ZnO co-catalyst. The study shows that effectiveness of the FR-CL-PA reaction to form a crosslinked structure is enhanced by the co-catalytic reaction, resulting in enhancement of fabric’s compressional recovering ability. However, the low pH reaction weakened the fabrics, resulting in poor tensile strength and toughness, stiffer hand feel, brittle and tendered polymer layers, a less spongy fabric structure, and a roughened fabric surface with fuzzy fibrils. In addition, atmospheric pressure plasma jet (APPJ) was used to enhance materials properties by sputtering or etching effect. The roughening effect of plasma treatment enhances tensile properties of treated specimens. Nevertheless, the positive effect is negligible after post-treatment with flame-retardant agents. Moreover, the increased inter-yarn friction enhances the subjective stiffness of fabric and the rigid effect is even worse for plasma pre-treated cotton specimens subjected to flame-retardant treatment. However, plasma pre-treated specimens have a compressible structure after post-treatment with flame-retardant agents. Moreover, neutralization of flame-retardant-treated specimens helps minimize side effects of acidic finishing, irrespective of tensile and compression properties. The process also minimizes shear and bending rigid effect by removing unattached metal oxides from the fabrics.