Synthesis of Hydrophilic Polyamide Copolymers Based on Nylon 6 and Nylon 46

Hydrophilic polyamide copolymers were successfully synthesized based on Nylon 6 and Nylon 46. This study aims to synthesize hydrophilic polyamides with moisture regain ability comparable to that of cotton. Random copolymers of nylon 6 and nylon 46 did not exhibit moisture regain rates higher than 6 %. A limited introduction of trifunctional monomer, diethylenetriamine (TA) produced the polyamides with higher mechanical strengths but failed to enhance the moisture regain. The incorporation of poly(ethylene oxide) oligomer with amine end groups increased the moisture regain but resulted in poor hydro-thermal and mechanical strength. A synergic effect was observed for copolymers which contain both nylon 46 units and PEO oligomer in regards to moisture regain capacity. Furthermore, the poor hydro-thermal and mechanical strength of Nylon/PEO segmented polyamides were drastically improved by the introduction of diethylenetriamine (TA). This study demonstrated that the polyamide copolymers comprising both PEO oligomer and TA unit record tensile moduli over 3 GPa and moisture regain rates of 8–10 wt%.