Mechanical properties of poly(ε‐caprolactone) composites with electrospun cellulose nanofibers surface modified by 3‐aminopropyltriethoxysilane

ABSTRACT To enhance the reinforcement effects of regenerated cellulose nanofibers (RC‐NF) in poly(ε‐caprolactone) (PCL), we synthesized RC‐NF‐3‐aminopropyltriethoxysilane (APS), the surface‐modified RC‐NF by APS. The RC‐NF were fabricated by the saponification of electrospun cellulose–acetate nanofibers. The surface modification by APS was confirmed by the X‐ray photoelectron spectroscopy (XPS). To enhance the mechanical property of PCL, the RC‐NF and the RC‐NF‐APS were separately compounded into PCL by compression molding. It was found that, when the fiber concentration of RC‐NF‐APS was 17 wt %, the Young's modulus at room temperature increased from 698.0 to 744.7 MPa, whereas the storage modulus at 55 °C almost increased from 180 to 220 MPa. The micrographs of the fracture surface of the composites revealed that the surface modification prevented the pull‐out of RC‐NF from PCL. It was concluded that the mechanical properties of the composites were enhanced due to the improvement of the compatibility between RC‐NF and PCL by the surface modification with APS. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48599.