Effects of nanoparticle size and concentration on optical, toughness, and thermal properties of polycarbonate

Abstract

ABSTRACT The influences of size and content of silicon dioxide (SiO 2 ) nanoparticles on the morphological, optical, toughness, and thermal properties of polycarbonate (PC) were investigated. The PC nanocomposites were prepared using a twin‐screw extruder followed by injection molding. The scanning electron microscope (SEM) micrographs displayed an adequate level of nano‐SiO 2 particle distribution within the PC matrix but still revealed some agglomerated particles. Upon increasing the content of nanoparticles, slightly larger agglomerates formed. These agglomerated particles caused a reduction in material transparency due to light loss via reflection and scattering. However, the incorporation of nano‐SiO 2 into the PC matrix greatly improved toughness properties and slightly increased glass‐transition temperature ( T g ), in conjunction with filler content (up to 4 vol %). This was particularly in the case with the smaller sized nano‐SiO 2 , which not only significantly improved toughness but also enhanced optical properties of the PC nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47634.