Polymer gasoline isobutylene polymerization

The propylene-butylene fraction constitutes a large part of the useful hydrocarbons produced by synthesis. It differs from similar fractions derived from petroleum refining in its high olefin (over 80%) and low isobutylene content, but this is no handicap in converting it to high octane gasoline by polymerization or by alkylation, if isobutane is available from another source. Polymerization is effected readily over a phosphoric acid on quartz catalyst with high conversion of propylene as well as butylene. The polymer... 

Polyisobutylenes are easily made via the acid-catalyzed polymerization of isobutylene. The low molecular weight polymers are used as additives for gasoline and lubricating oils, whereas higher molecular weight polymers are used as adhesives, sealants, caulks, and protective insulation. 

In 1935 Shell began to produce high-octane gasoline at three of its refineries in California, Texas, and Illinois. It developed a cold-acid polymerization process that treated butanes, butylenes, and isobutylenes to produce di-isobutylene, a polymer product that was then hydrogenated to make isooctane, a key ingredient in 100-octane gasoline. The next year, the process was improved through a hot acid technique. Then in 1939 came an even more efficient process called alkylation, in which isobutylene and butylenes were polymerized. ... 

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