Effect of interfacial interactions on the crystal growth rate in model PE/SiO2 nanocomposites: Comparing experiments with Lauritzen-Hoffman model and MD simulation

Abstract

Nanoparticles with engineered surface chemistry represent novel means in controlling the in-situ formation of property-specific supramolecular structure in advanced processing technologies of semicrystalline polymers. Often, the published experimental data on effects of interfacial adhesion on the crystallization kinetics of polymer nanocomposites report contradictory results even for similar systems. Computer simulations allow separating structural and test variables, thus, can provide useful framework for understanding these apparent controversies. Our MD simulation of Regime II crystallization showed that adding non-nucleating spherical nanoparticles reduced the crystal growth rate, GII, compared with the neat polymer with the extent of the reduction proportional to the strength of interfacial attraction. It also suggested that, regardless of the strength of the interfacial interactions, additional reduction of the GII was caused by topological constraints imposed by nanoparticles on the stem attachment. Both the Lauritzen-Hoffman model predicted and MD simulated GII reduction agreed fairly well with that obtained experimentally for monodisperse PE filled with nanometer-sized SiO2. POLYM. ENG. SCI., 53:2696–2704, 2013. © 2013 Society of Plastics Engineers