Abstract: Melt preparation of polyarylate with catalyst system comprising an imidazole.

Abstract: Bis(hydroxyphenyl)methanes are prepared by reaction of phenol and formaldehyde in a two-phase mixture containing aqueous phosphoric acid. The reaction conditions can be selected to provide high yields of bis(hydroxyphenyl)methanes or to yield bis(hydroxyphenyl)methanes containing a high concentration of the 4,4'-isomer.

Abstract: A normally amorphous condensation polymer is crystallized by foaming it with a chemical blowing agent at a temperature above the softening point of the polymer, extruding the molten polymer to form a solid foam and maintaining the foam at a temperature above the glass transition temperature until crystallization occurs. The crystallized polymer foam may be used as a structural foam. It can be used in solid state polymerization to obtain polymers of enhanced degree of polymerization.

Abstract: Trichlorofluoromethane is used as a promoter in the polymerization and copolymerization of ethylene with supported Ziegler-type vanadium compound/alkylaluminum compound catalysts in the presence of hydrogen. The use of the promoter leads to the formation of non-rubbery, semi-crystalline polymers in high yields, does not alter the basic molecular weight distribution of the polymers, permits independent control of molecular weight by hydrogen, and imparts no significant level of halogen to the product.

Abstract: A normally amorphous condensation polymer is crystallized by foaming it with a chemical blowing agent at a temperature above the softening point of the polymer, extruding the molten polymer to form a solid foam and maintaining the foam at a temperature above the glass transition temperature until crystallization occurs. The crystallized polymer foam may be used as a structural foam. It can be used in solid state polymerization to obtain polymers of enhanced degree of polymerization.

Abstract: A process for the preparation of polyarylene esters from aromatic dicarboxylic acids and diesters of a diphenol admixture containing 1,2-bis(4-hydroxyphenyl)ethane. The polymerization process is catalyzed by a potassium compound and yields polymer of improved color and fire safety performance.

Abstract: A supported catalyst for the polymerization and copolymerization of ethylene in the presence of hydrogen as a molecular weight control agent is prepared by depositing upon silica gel which has been reacted with an alkylaluminum or an alkylaluminum alkoxide, a catalytic composition consisting essentially of a compound of vanadium, a trialkylaluminum and an alkylaluminum alkoxide, said catalytic composition having been prepared by combining said vanadium compound with said alkylaluminum alkoxide and thereafter combining the reaction mixture with said trialkylaluminum. The supported catalyst so prepared exhibits greater activity than does the same catalyst composition supported on untreated silica gel.