Nondestructive Modification of Catechol/Polyethyleneimine onto Polyester Fabrics by Mussel-Inspiration for Improving Interfacial Performance

Co-deposition of catechol and polyethyleneimine onto polyethylene phthalate (PET) fiber by mussel-inspiration is conducted and subsequently utilized to prepare polyethyleneimine/catechol modified PET fiber reinforced composites (polyethyleneimine (PEI)/CCh-m-PET FRCs). The surface polarity is characterized through the dynamic contact angle. The mechanical performances including tensile, flexural, and short beam shear strength are evaluated. Additionally, the single-bundle pull-out tests are carried out with the double-end method. The analysis reveals that compared to the untreated PET reinforced composite, there are 33.49% and 34.35% increase of the critical load and peak load for PEI-modified specimens, respectively, meanwhile the critical debonding energy and pull-out energy calculated increase by 28.46% and 24.47%, respectively. The interlaminar shear strength and interfacial shear strength of modified PET can reach the values of 145.89 and 20.88 MPa, which are significantly improved by 58.01% and 70.94%.