Allyl acetate cationic polymerization

The polymerization of allyl acetate has been studied reasonably extensively in the effort to elucidate the mechanisms of the polymerization process. The utility of poly(allyl acetate) as a resin is believed to be negligible. Nevertheless, this compound has been polymerized in bulk, in solution, and in emulsion. There is mention of a cationic polymerization process and of radiation-induced charge-transfer processes. 

Cationic polymerizations of allyl esters require further investigation. Schild-knecht [7] mentions the polymerization of allyl acetate and of allyl formate in benzene solution upon heating the solution with 6% of benzenediazonium fluoroborate under nitrogen at 200°C in sealed tubes. The solid products melt at about 190°C (d) and are soluble in benzene and insoluble in methanol. 

Included among the many types of vinyl monomers that have been subjected to photoinitiated cationic polymerization are styrene," substituted styrenes, a-methylstyrenes, N-vinylcarbazole, alkyl vinyl ethers, prop-l-en-l-yl ethers, ketene acetals, and alkoxyallenes. Most useful in the crosslinking photopolymerizations employed for UV curing applications are multifunctional vinyl ethers and multifunctional prop-l-en-l-yl ethers. A number of multifunctional vinyl ether monomers are available from commercial sources, while multifunctional prop-l-en-l-yl ethers can be readily prepared by catalytic isomerization from their corresponding allyl ether precursors. The photoinitiated cationic... 

A spectacular example of cationic cyclization is the Johnson polyene cyclization, described in Section 10.8.A. Polyenes such as squalene are expected to assume a steroid-like conformation in the lowest energy form (sec. 1.5.E), based on the biogenetic preparation of cholesterol from squalene. In practice, treatment of polyenes with acid led to a very low yield of tri- or tetracyclic products, giving instead significant amounts of polymeric material. Diligent work over many years prevailed, however, and Johnson solved the many problems (as described in sec. 10.8.A) to make this reaction an excellent and efficient synthetic route to di-, tri-, and tetracyclic molecules. One of the later examples of polyene cyclization uses an allyl silane to quench the cyclization process. A Lewis acid was used to initiate the reaction via reaction with the acetal. Treatment of... 

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