Functionalization of cellulosic substrate using He/dodecyl acrylate plasma at atmospheric pressure

•APGD plasma has been used for in-situ hydrophobic functionalization of viscose.•Water contact angle of ~ 143° was obtained.•Reaction of a non-fluoro hydrocarbon resulted in wash durable treatment.•Plasma reaction was strongly influenced by plasma energy and frequency.•Surface chemical analysis confirmed the presence of hydrophobic moieties.

Hydrophobic functionalization of viscose fabric was carried out using long chain hydrocarbon compound dodecyl acrylate (DA). The treatment was carried out in-situ using DA/helium atmospheric pressure plasma at low frequency. After the treatment, the water absorbency time of the substrate was more than 1 h and water contact angle was 143°. The functional property developed after the treatment was durable to both solvent and soap washing. Effect of various parameters such as concentration of precursor, helium flow rate, discharge voltage, discharge frequency and treatment time on functionalization was investigated. Plasma was characterized using oscilloscope, optical emission spectroscopy (OES) and gas chromatography–mass spectrometry (GC–MS). Modification of chemical nature of the fabric surface was characterized by ATR-FTIR, Raman, and Secondary ion mass spectroscopies. The study of the surface morphology by FE-SEM revealed the formation of a uniform thin layer on individual fibres. The fabric was found to retain its tensile strength after plasma treatment. The plasma characteristics were correlated with hydrophobic functionalization at different treatment parameters.