Simultaneous enhancements of mechanical properties and hydrophilic properties of polypropylene via nano-silicon dioxide modified by polydopamine

This study is focused on the development of high-performance composite materials based on nano silicon dioxide (nano-SiO 2 ) modified by polydopamine (PDA). A facile one-step method was developed to synthesize core–shell structured SiO 2 @polydopamine (PDA) nanospheres. During the synthesis, a PDA shell was simultaneously coated on the SiO 2 nanospheres to form the core–shell nanostructure which was blended with polypropylene (PP) and β nucleating agent (β-NA) to enhance both mechanical and hydrophilic properties. Nano-SiO 2 particles modified by PDA (SiO 2 @polydopamine) influence the crystallization of PP seriously. The results indicated that when 1%wt SiO 2 @polydopamine was added, the impact strength of composite reached the maximum value 12.60k J/m 2 increasing 137% compared with PP, the bending strength and bending modulus decreased slightly reaching 41.85 MPa, and 2192 MPa, respectively, the composite possessed hydrophilic performance with the water contact angle of 88.32°. β nucleating agent was used in all formulations, the synergistic effect toward mechanical properties with SiO 2 @polydopamine was studied. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45004.