Preparation and properties of hydrophobic materials based on environmentally responsive low fluorine epoxy copolymer

Abstract

Hydrophobic surfaces and super hydrophobic surfaces have been widely studied and applied to cotton, ceramics, glass and other surfaces, but less research has been done on environmentally responsive hydrophobic surfaces (ERHS). In this paper, the environmentally responsive low fluorine epoxy copolymer P(DMAEMA-r-TFEMA-r-GMA) was synthesized by traditional free radical polymerization and the obtained copolymer was applied to construct ERHS on the cotton fabric and wood/plastic composite (WPC). The effects of construction parameters (polymer concentration, pH value of impregnation solution, impregnation temperature, impregnation time, drying temperature and drying time) on the surface hydrophobic properties of cotton fabric and WPC were studied. L25 (56) orthogonal experiment scheme was selected to explore the optimal parameters of hydrophobic construction. The optimum construction conditions of ERHS cotton and ERHS WPC were as follows: polymer concentration of 10 mg/mL, impregnation time of 9 h, pH of 9, impregnation temperature of 50 °C and 60 °C, drying time of 6 h, and drying temperature of 120 °C. The maximum water contact angle (WCA) on the surface of ERHS cotton was 145°. After 15 times pH-stimulation circulations, the WCA changed in the range of 145° ± 5° to 120° ± 5°. After 10 times acid-base response circulations, ERHS cotton had good oil-water separation capacity, and the maximum oil-water separation rate varied from 99.82% to 98.24%. This hydrophobic modification had no effect on the thermal stability of cotton fabric. The maximum WCA of ERHS WPC was 135°. Under acidic conditions (pH=2), the water absorption rate of wood plastic was improved. The hydrophobic modification had little effect on the mechanical properties and thermal stability of WPC.