Experimental cum computational investigation on interfacial and mechanical behavior of short glass fiber reinforced dental composites

Achieving strong filler/matrix interactions is essential in the design and manufacturing of composite systems. Molecular dynamics simulation has played a vital role in the investigation of interfacial behavior by predicting the mechanical properties of polymer-based composites. There has been, however, a big gap for clearly establishing a correlation between simulations and experiments because of limitations in size and time scale. Herein, a comparative analysis on the interfacial adhesion behavior of the short glass fiber and dental resin matrix is performed combining the atomistic simulations and single fiber/microdroplet pull-out tests in micro-scale. The interfacial shear strength is measured at the molecular level by applying the scale factor on the glass fiber, and the simulations are compared with the experimental results of the pull-out tests. The enhanced reinforcement effects induced by the surface modification via silane coupling agents grafting on the glass fibers are verified in both studies. Moreover, the mechanical properties and dynamic behavior of the dental composites under the longitudinal and transverse tension loadings are examined with quantifying the free volume changes. The findings of this research provide the optimized design guidelines to precisely predict the mechanical performances of the short fiber reinforced dental composites via molecular dynamics simulations and experiments.