Construction of unsaturated systems on the surface of polyamide fibers

The design and development of functional superfine fiber substrates are a recent research hotspot in the industry. In this study, the materials of superfine polyamide fibers were used to hydrolyze under acidic conditions to produce amino and carboxyl groups on the surface of polyamide fibers. Then, methacrylic anhydride was used to react with the amino groups of the fibers, so that carbon–carbon double bonds were introduced to the surface of the polyamide fiber and the surface of the polyamide fiber with a carbon–carbon double bond was obtained. In this paper, the effects of methacrylic anhydride dosage, reaction time and reaction temperature on the carbon–carbon double bond content were systematically investigated and characterized by ATR-IR and nuclear magnetic resonance. The results show that the amount of methacrylic anhydride was 1.2 mL, the reaction temperature was 50°C, and the reaction time was 2 h. The polyamide methacrylamide fiber contained the most carbon–carbon double bonds, and the grafted double bond content of the modified polyamide fiber was 6.39% of its dry weight.