New technologies demand new materials. Polymer composites, with their wide range of possible fillers and polymers, open the way to an enormous range of materials with differing chemical, physical, and mechanical properties. The ultimate goal of polymer composite research is to formulate procedures that will lead to the design of composites with preset, i.e. specified, properties. Based on many years' experience in the field, the authors prepare the way towards just such a design procedure. The key element is the analysis and classification of the state of the filler-polymer interfaces from the point of view of their acid-base adsorption interactions. These interfacial phenomena play a pivotal role in determining overall properties of the composite: its rheological behaviour, its structural properties, catalytic effects in polymerization and polycondensation, and other technological characteristics. The book discusses and evaluates the extensive previous research scattered throughout the literature in Eastern Europe and the West, presents numerous experimental studies, and sets new benchmarks for the analysis of polymer composites. The book is required for researchers wanting to keep abreast of the progress in the burgeoning fields of polymer analysis and design.