ABSTRACT
A more specialized addition reaction is the epoxidation of the double bonds in natural rubber, either to increase polarity for direct physical compatibilization or for further compatibilization reactions. Practical reactive compatibilization requires two polymers that can react with each other or a third polymer that can react with one or both of them, or at least a monomeric additive that can react with them or catalyze a reaction between them. Commercial polymers can also be modified by substitution reactions to introduce polar, hydrogen-bonding, or ionic groups for use as physical compatibilizers. Polymer blending has a long commercial history in the rubber, coatings, and ad-hesives industries, and it entered the plastics industry a half century ago. Kinetics of phase separation and morphology formation are slowed by the entanglement of large polymer molecules and the high viscosity of such large entangled molecules.
