Synthesis of polysiloxaneurethane polymers by the aromatic isocyanate-activated opening of the octamethyltetrasiloxane ring via an anionic mechanism
Tóm tắt
Here, we present the results of the study of the interaction in the octamethylcyclotetrasiloxane-aromatic isocyanate-open coupling analogues system of crown ethers containing terminal hydroxyl and potassium alkoxide groups. It was found that the involvement of the organosiloxane cycle in the polymerization process precedes the opening of the isocyanate groups on the carbonyl component. It is shown that the formation of transverse cross-linking bonds in the polymer formation system is caused by the parallel reaction of cyclotrimerization. It is found that the ratio of the reaction rate constants of the copolymerization and the parallel reactions of cyclotrimerization and urethane formation depend on the synthesis temperature.
Tài liệu tham khảo
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