Abstract: Provided is a process for preparing alumina agglomerates which comprises:(i) treating agglomerates of active alumina with an aqueous medium comprising at least one acid making it possible to dissolve at least part of the alumina and at least one compound providing an anion capable of combining with aluminum ions in solution,(ii) subjecting the agglomerates to a hydrothermal treatment at a temperature in the range of from about 80.degree. C. to about 250.degree. C., and then(iii) thermally activating the agglomerates at a temperature in the range of about 500.degree. C. to about 1100.degree. C.The resulting alumina agglomerates possess exceptional mechanical strength, heat resistance and hydrothermal resistance and are useful as catalysts or catalyst supports.

Abstract: Provided is a process for preparing alumina agglomerates which comprises:(i) treating agglomerates of active alumina with an aqueous medium comprising at least one acid making it possible to dissolve at least part of the alumina and at least one compound providing an anion capable of combining with aluminum ions in solution,(ii) subjecting the agglomerates to a hydrothermal treatment at a temperature in the range of from about 80.degree. C. to about 250.degree. C., and then(iii) thermally activating the agglomerates at a temperature in the range of about 500.degree. C. to about 1100.degree. C.The resulting alumina agglomerates possess exceptional mechanical strength, heat resistance and hydrothermal resistance and are useful as catalysts or catalyst supports.

Abstract: Novel lubricating oil polymer additives are obtained by the following:(1) by preparing, by anionic polymerization, a living diene polymer of Mn of between about 20,000 and 300,000;(2) by functionalizing the said polymer by means of an N-substituted lactam of the type of N-alkylcaprolactam, N-binylcaprolactam, and particularly of the type of N-alkylpyrrolidione and N-vinylpyrrolidone; and(3) by hydrogenating the said functionalized polymer.A variant method of preparing the said polymers comprises subjecting the living polymer to a metalation operation before functionalization; the hydrogenation operation is carried out before metalation or after functionalization.The said polymers may be used as additives which improve the viscosity index and the dispersing power of lubricating oils. The amount of additive added is between about 0.1 and 10 percent by weight.