The relationships between mixing and properties of filled polymers and foams

The increased utilization of reinforced polymeric blend composite materials has prompted renewed interest in mathematical models which can explain or predict the characteristics of processing and the properties of composite materials in terms of the properties and concentration of the components. As a first step toward developing the rules for multicomponent systems we restrict our attention to the Lee-Nielsen's model and concepts of two-component systems with particulate inclusions embedded in a continuous matrix. The following property-mixing relationships are then discussed: (1) reinforcement of uncured and cured rubber composites; (2) thermal expansion of polymer composites; (3) elastic modulus, and thermal conductivity of (reinforced) polymeric foam materials; and (4) heat buildup of rubber composites. Some important concepts and principles which have evolved from our experimental attempts at correlating the behavior of heterogeneous multiphase polymer materials are also discussed.