Surface modification of bundle-type polyamide fiber nonwoven with collagen to improve its hydrophilicity

In this work, surface modification is employed to improve the functionality of bundle-type polyamide fiber nonwoven (PAFN) by a simple method. Firstly, PAFN was treated with formaldehyde to get hydroxylated PAFN (PAFN-OH) with N-hydroxymethyl structure, and then PAFN-OH was modified by using (3-aminopropyl) trimethoxysilane (APS) to prepare silanized PAFN (PAFN-NH2). Secondly, ester-functionalized PAFN (PAFN-COO) was prepared by Michael 1,4 conjugate addition of PAFN-NH2 and dipentaerythritol pentaacrylate (5Acl). Finally, PAFN-COO was modified with collagen to evaluate the hydrophilicity of the functionalized PAFN (PAFN-g). The scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) spectra provided evidence for the modification from PAFN to PAFN-g. Moreover, the atomic force microscopy (AFM) shows the change in surface roughness of PAFN and modified PAFN. The water vapor transmission rate was increased 137.4% and the water contact angles decreased from 124.2° to 68.3° by comparing PAFN with PAFN-g. This indicated that the hydrophilicity of PAFN modified by collagen was improved significantly.