Chemical reactions can be made to occur using miscible polymer blends that offer the opportunity for the design of new material systems with enhancements in properties and/or processing. We will study miscible polymer blends containing silanol and phosphonic acid substituents as H-bond donors with a variety of H-bond acceptor polymers. These systems are new types of miscible blends. The specific interaction should stabilize the silanol function and prevent its premature reaction with itself to give siloxane. However, at temperatures above the lower critical solution temperature, phase separation and subsequent siloxane formation should occur, thereby giving fast-curing polymer networks. Phosphorus-containing structures have wide use for decreasing flammability. In some systems by enhance condensed-phase reactions at elevated temperatures leading to "char" or residue enhancement and decreased flammability. This will be studied in miscible blends containing phosphonic acid function e.g., with styrene copolymers containing the hydrogen-bond donor groups in the para position.