Study of the effect of particle size on the effective modulus of polymeric composites on the basis of the molecular chain network microstructure

Particle size largely influences the mechanical behaviors of polymeric composites, and such effect is derived from the synergism mechanism between particles and the host matrix. This paper is supposed to develop a molecular-chain-network based micromechanics model for exploring particle size effect on the effective modulus of the composites. In the present model, particles are regarded as junctions among molecular chains, which are equivalent to the cross-links pre-existing in the net polymer matrix. At a certain particle concentration, the smaller the particle size, the higher is the cross-link density in the composites, and the higher is the effective stiffness of the resulting composites. Based on this inter-relationship, particle size effect would be clearly demonstrated from a new point of view, which is different from any previous interpretations.