Polymer–Polymer Miscibility discusses miscibility of polymeric mixtures. This book explains the theoretical and practical aspects of polymer miscibility, which has become a considerable area of research in many academic and industrial laboratories. Comprised of seven chapters, this book starts with an overview of the physical nature of the variations of the basic polymer structure. This monograph then discusses the two cases of miscible polymer blends, namely, poly(vinyl chloride) (PVC)–butadiene/acrylonitrile copolymer (NBR) and polystyrene–poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) blends. This text explores the useful and unique properties of blends of poly(vinyl chloride) and butadiene/acrylonitrile copolymer rubber. Other chapters discuss the thermodynamic theories for the phase separation of block copolymers. The reader is also introduced to other variations of chemical structure, which can result in the permanent attachment of polymers to each other through block and graft copolymers. This text also explores the feasibility of covalent bonding of polymer components. This book is intended for chemical engineers and materials scientists.