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Epoxidation Reactions

المؤلف:  A. Ravve

المصدر:  Principles of Polymer Chemistry

الجزء والصفحة:  p583-584

2026-02-21

337

Epoxidation Reactions

These addition reactions of unsaturated polymers, like liquid polybutadiene, developed into preparations of useful commercial materials [88–94]. Patent literature describes procedures that use hydrogen peroxide in the presence of organic acids or their heavy metal salts. Reaction conditions place a limitation on the molecular weights of the polymers, because it is easier to handle lower viscosity solutions. A modification of the procedures is to use peracetic acid in place of hydrogen peroxide [95–97]. The most efficient methods rely upon formations of organic peracids in situ with cationic exchange resins acting as catalysts [98]. This can be illustrated as follows:

The reaction is accompanied by formations of by-products:

Polybutadienes that are high in 1,4-structures tend to epoxidize more readily and yield less viscous products [100, 101]. The epoxidation reaction can also be carried out on poly (1,4-cyclopentadiene) [99]:

Perbenzoic acid is an effective reagent in chloroform and in methylene chloride solutions at 0–20C. The conversions are high, yielding brittle materials soluble in many solvents. The products can be cast into transparent films [99]. Monoperphthalic and p-nitroperbenzoic acids are also efficient epoxidizing agents. They can, however, cause cross-linking, as is the case in epoxidation of polycyclopentadiene [99]. The products react like typical epoxy compounds [99]:

Some other reactions of the epoxy groups are [99]: