Elastic surface coatings with cross-linking networks for strengthening glass fibers in scale-up production

Abstract

Abstract Epoxy based glass fiber (GF) sizing emulsion has been widely used to strengthen GFs and to provide the fibers with compatibility and adhesion to matrix. However, most of the commercial sizing emulsions cannot form surface coatings with good elasticity to effectively strengthen GFs. Herein, we reported an elastic surface coating with cross-linking networks by introducing polyethyleneimine (PEI) into commercial epoxy GF size emulsion. The advanced surface coatings show an improved elasticity and a strong interfacial effect with glass, which could significantly strengthen GFs. When the addition ration of PEI to epoxy based sizing emulsion is 0.6 wt.‰, the obtained elastic coating on GF surface shows a roughness increased from 6.26 to 25.1. The coated GFs have a surface energy of 42.88 mN m-1, an average tensile strength of 0.694 N/Tex, and a transverse fiber bundle tension (TFBT) strength of 46.42 MPa. The results suggest that PEI/epoxy based sizing emulsion can form elastic coatings on GF surface and could be used as a high performance size to effectively strengthen GFs during continuous scale-up production of GFs.