Preparation and characterization of long‐chain branched PA6 by UV‐irradiation of included methacrylate monomers after extrusion

Abstract

AbstractTo improve melt strength and toughness of polyamide 6 (PA6), an on‐line UV radiation method is introduced into reaction extrusion to induce free radical reaction for efficient preparation of long‐chain branched PA6 materials. Trimethylolpropane triacrylate and glycidyl methacrylate are adopted as chain extenders to synergistically introduce long‐chain branches onto PA6 macromolecules. Gel permeation chromatography results show the increase of molecular weight of PA6, implying the successful graft of chain extenders onto molecular chains. Based on rheological measurement results, modified PA6 exhibits better melt strength than pure PA6 owing to a larger storage modulus. The elongation at break and impact strength of modified PA6 at T1G1 are about 5.3 and 2.2 times those of pure PA6, respectively, without sacrificing tensile strength. According to Fourier transform infrared spectroscopy results, we propose reaction mechanisms between trimethylolpropane triacrylate/glycidyl methacrylate and PA6 under on‐line UV radiation. This study offers a practical approach for the efficient preparation of long‐chain branched PA6, thereby broadening the potential applications of the material.Highlights An on‐line UV radiation method is introduced into reaction extrusion. The melt strength and toughness of polyamide 6 are realized simultaneously at low cost. The synergistic effect mechanism of trimethylolpropane triacrylate and glycidyl methacrylate is proposed. Provides a feasible way to efficiently prepare long‐chain branched polyamide 6.