Abstract: This invention relates to a process for preparing 1-oxo-1,2,3,4-tetrahydronaphtahalene(.alpha.-tetralone) in high yield and high selectivity from the liquid phase oxidation of tetralin in a bubble column reactor under several homogeneous and heterogeneous catalyst systems such as hexavalent chromium oxide, silica-supported chromium oxide,and insoluble material from the homogeneous oxidation mixture in N,N-dialkyl acid amides.

Abstract: Plastic foam materials having a high degree of structural integrity, cell network uniformity and small cell size are obtained from (meth)acrylic acid and (meth)acrylonitrile by incorporating acrylamide as a comonomer additive within certain ranges of concentration. Incorporation of the latter together with conventional additives normally used in preparing foams from the principal monomers helps to avoid preliminary precipitation during the polymerization process, and the gradients in the polymer microstructure which frequently result and cause internal stresses and weaknesses in the ultimate product.

Abstract: Plastic foam materials having a high degree of structural integrity, cell network uniformity and small cell size are obtained from (meth)acrylic acid and (meth)acrylonitrile by incorporating acrylamide as a comonomer additive within certain ranges of concentration. Incorporation of the latter together with conventional additives normally used in preparing foams from the principal monomers helps to avoid preliminary precipitation during the polymerization process, and the gradients in the polymer microstructure which frequently result and cause internal stresses and weaknesses in the ultimate product.

Abstract: Open-cell structures are filled with polyimide foam formed in place by the use of a foam precursor in powdered form comprised of a combination of (a) the reaction product of an excess of organic polyisocyanate and a member selected from the group consisting of furfuryl alcohol and condensation products thereof, and (b) an organic polycarboxylic compound containing two carboxylic anhydride groups. The precursor is prepared by combining the species under conditions which favor the reaction of the furfuryl alcohol with the polyisocyanate, but not the polyimide-forming reaction. The polyimide-forming reaction itself is then performed by adding preselected amounts of the powdered precursor, depending on the desired ultimate density of the foam, to each cell of the open-cell structure, then heating to initiate the polyimide reaction, and permitting the carbon dioxide generated by the reaction to escape while confining the resulting foam to the cells.

Abstract: Open-cell structures are filled with polyimide foam formed in place by the use of a foam precursor in powdered form comprised of a combination of (a) the reaction product of an excess of organic polyisocyanate and a member selected from the group consisting of furfuryl alcohol and condensation products thereof, and (b) an organic polycarboxylic compound containing two carboxylic anhydride groups. The precursor is prepared by combining the species under conditions which favor the reaction of the furfuryl alcohol with the polyisocyanate, but not the polyimide-forming reaction. The polyimide-forming reaction itself is then performed by adding preselected amounts of the powdered precursor, depending on the desired ultimate density of the foam, to each cell of the open-cell structure, then heating to initiate the polyimide reaction, and permitting the carbon dioxide generated by the reaction to escape while confining the resulting foam to the cells.

Abstract: Open-cell structures are filled with polyimide foam formed in place by the use of a foam precursor in powdered form comprised of a combination of (a) the reaction product of an excess of organic polyisocyanate and a member selected from the group consisting of furfuryl alcohol and condensation products thereof, and (b) an organic polycarboxylic compound containing two carboxylic anhydride groups. The precursor is prepared by combining the species under conditions which favor the reaction of the furfuryl alcohol with the polyisocyanate, but not the polyimide-forming reaction. The polyimide-forming reaction itself is then performed by adding preselected amounts of the powdered precursor, depending on the desired ultimate density of the foam, to each cell of the open-cell structure, then heating to initiate the polyimide reaction, and permitting the carbon dioxide generated by the reaction to escape while confining the resulting foam to the cells.

Abstract: There is disclosed a suspension polymerization of vinyl chloride in which the suspension of monomers as droplets is maintained, and the droplets of polymer are prevented from coalescence by the addition of an expanding lattice clay, preferably a magnesium alumina silicate clay, most preferably, Veegum, and a hydrophilic polymer. The hydrophilic polymer can be a partially hydrolized polyvinyl alcohol, a hydroxyalkyl cellulose ether, or a cross-linked polyacrylic acid, the latter being preferred. These addities enhance polymerization by reducing polymerization time and reducing deposition of the polymer in the reactor. Additionally, the shape and particle size distribution of the polymer is improved.