This volume explains the theory and experimental investigations in the preparation of heterophase polymer network materials through cure reaction-induced microphase separation (CRIMPS). It describes the synthesis of a new family of block- and graft-copolymers with controlled solubility in epoxies and characterizes CRIMPS processes using novel applications of known methods such as nuclear magnetic resonance, electron spin resonance and photochemistry. The text develops a new method for characterizing the molecular mass distribution (MMD) of linear and network polymers using thermomechanical analysis data, as well as new methods for determining internal stresses and flaw formation during thermoset curing. The CRIMPS theory will be helpful for researchers and engineers designing and improving toughened plastics and other smart heterophase network materials for different applications. The new method for MMD characterization of polymers in bulk will be very useful to quickly analyze a polymer's MMD and to design new polymers. This book will provide a useful reference for graduates, researchers and working professionals in polymer chemistry and physics and materials science.