Synthesis of non-fluorinated paraffinic water repellents and application properties on textile fabrics

The five non-fluorinated paraffinic water repellents having different lengths of alkyl groups were synthesized by emulsion polymerization. The number and weight average molecular weights were obtained at around 86,000-150,000 and 170,000-470,000, respectively. As the length of alkyl groups increased, the average molecular weight tended to decrease and the melting points gradually increased from 4.8 °C to 66.7 °C. The optimum length of alkyl group of paraffinic water repellents could be determined as hexadecyl and octadecyl and they showed the contact angle higher than 130 °. The critical surface tensions were obtained at 20-21 mN/m, there was no significant difference according to the length of alkyl groups between hexadecyl and docosyl groups.