A mechanical model for predicting the thermal expansion behavior of spherical particle reinforced epoxy composites

Modeling and theoretical prediction of thermal expansion property of particulate reinforced polymer composite are important hot issues in composite science and engineering. In this article, the thermomechanical interaction between spherical particle and polymer matrix and its contribution to the thermal expansion behavior of spherical particle reinforced polymer composite have been studied theoretically. A mechanical interphase resulted from the thermomechanical interaction is observed in radial distribution of effective coefficient of thermal expansion (CTE) around the particle with an isotropic assumption of the particle and polymer matrix, and with necessary simplification of the thermomechanical interference among particles, an analytical equation for predicting the CTE of the composite has been proposed. Compared with other models, good fits by this model with finite element (FE) simulated CTE value of particle reinforced composite and previously reported CTE data of particulate reinforced epoxy composites with particle size from micron to nanometer scale are observed. This study would deepen the understanding of the interphase in particle reinforced composites and be favorable for mechanism analysis of other physical properties of polymer composites.Highlights Thermomechanical interaction between spherical particle and matrix is studied A new model for the CTE of particle reinforced polymer composite is proposed FE simulation been carried out to examine the reasonability of the proposed model Present model well fits the reported reinforced epoxy composites CTE data A new perspective for analyzing other properties of reinforced composites The thermomechanical interaction between the spherical particle and polymer matrix would affect the effective coefficient of thermal expansion (CTE) distribution around the particle, and in spherical particle reinforced polymer composite, the thermomechanical interaction would interfere with each other complexing the thermal expansion behavior of the composite. Our model shows a good fit with both FE simulated and experimental reported spherical particle reinforced epoxy composite CTE data. image