Abstract: This invention relates to the process for the preparation of polyurethane with controlled particle size and shape. More, particularly it relates to the production of polyurethane microspheres from a diol and diisocyanate by dispersion polymerization in presence of a steric stabilizer and a catalyst in an organic solvent at a controlled temperature, and finally separating the spherical polyurethane particles from the reaction mixture by conventional means.

Abstract: A process for the preparation of an inert oxide supported metal halide organo aluminium compound catalyst. The catalyst is obtained by reacting an activated support having surface hydroxyl groups with aluminium chloride selected from aluminium chloride solution and aluminium chloride vapors. A solution of an aluminium alkyl is added to the reacted support. The solvent is removed and the reacted support is dried.

Abstract: Polycarbonates are recycled without the need for chemical modification by dissolution in a solvent followed by removal of any insoluble materials and precipitation by addition of a non-solvent. The precipitation step may be followed by solid state polymerization of the recycled polycarbonate. Particularly when solid state polymerization is to be performed, the use of a combination of solvent and non-solvent which produces a crystalline intermediate is performed, and use of a modifying reagent increasing the hydroxy end group concentration of the polycarbonate may be advantageous.

Abstract: This invention relates to the process for the preparation of macromonomers with more than one polycondensable functional groups with equal reactvity, which comprises reacting a carboxyl or hydroxyl terminated prepolymers, with an organic compound containing two or more isocynnate reactive functional groups, in the presence of a dehydrating agent and a non-reactive solvent at ambient temperatures, separating the product from the reaction mixture by conventional means.

Abstract: A process for the preparation of heterogeneous zirconium based catalyst for polymerization of alpha-olefins to super high molecular weight poly (alpha-olefins). The process comprises in mixing zirconium alcholate or phenolate with anhydrous magnesium chloride in the presence of a solvent. The mixture is heated, then cooled and an organoaluminum compound is added. Optionally, an electron donor compound is added and heated to obtain a black slurry, which is cooled and then washed with a hydrocarbon diluent.

Abstract: A process for the oligomerization and co-oligomerization of alpha olefins by subjecting olefins to the step of oligomerization in the presence of a supported aluminum chloride catalyst and an organoaluminum compound as a promoter. The catalyst is separated and the reaction product is subjected to the step of fractional distillation for removal of the solvent. The oligomers are further fractionated to obtain poly alpha olefins.

Abstract: A process for the living anionic polymerization of alkyl(meth)acrylic monomers, involving polymerizing the monomers in the presence of an initiator comprising a carbanion and a metal or nonmetal salt of perchloric acid. The initiator has the formula (I): ##STR1## wherein R.sub.1 =a linear or branched alkyl group having one to six carbon atoms, R.sub.2 =a phenyl or alkyl group having one to six carbon atoms, R.sub.3 =a phenyl or an ester group and M.sup.+ is an alkali, alkaline earth metal or quarternary ammonium cation containing 1-8 carbon atoms in an alkyl group thereof.

Abstract: An improved method for the preparation of tris(4-hydroxyphenyl) compounds is provided. In particular, an improved method for preparing 1, 1, 1-tris(4'-hydroxyphenyl)ethane is provided which comprises heating a mixture comprising phenol and 4-hydroxy acetophenone in the presence of effective amounts of an ion exchange catalyst and a mercaptan as a copromoter such that the resulting 1, 1, 1-tris(4'-hydroxyphenyl)ethane is substantially free of various reaction impurities.

Abstract: This invention is directed to a process for the preparation of a supported metallocene catalyst, said process comprising preparing a precursor catalyst material by dissolving a magnesium halide in an electron donor solvent in which the magnesium halide is completely soluble, heating the solution to a temperature in the range of 20.degree. C. to the boiling point of the respective electron donor for a period ranging between 10 to 60 minutes, separately preparing a solution of the metallocene compound into the same electron donor solvent, heating the solution to a temperature in the range of 25.degree. C. to 70.degree. C. for a period ranging between 0.1 to 0.5 hrs., mixing the two solutions to obtain a homogenous solution of catalyst precursor compound, stirring and maintaining this resulting homogenous solution at a temperature in the range of 50.degree. C. to 70.degree. C. for a period of 0.5 to 2 hrs.

Abstract: The present invention is directed to a process for the preparation of a solid magnesium halide supported metallocene catalyst having a transition metal selected from the group consisting of IIIB, IVB, VB and VIB of the periodic table, which comprises preparing a slurry of magnesium metal in an electron donor solvent; heating the slurry of magnesium metal to 0.degree. C. to 50.degree. C. for a period of 10 minutes to 4 hr.; adding a dihaloalkane compound to said slurry to obtain a homogeneous solution of a support (solution A); separately preparing a solution of a metallocene compound in the same electron donor solvent as solution A (solution B); heating the solution B to 0.degree. C. to 50.degree. C. for a period ranging between 10 minutes and 1 hr., adding solution B to solution A over a period ranging between 10 minutes to 2 hrs. while maintaining the temperature in the range of 0 to 50.degree. C.

Abstract: The present invention relates to a process for the preparation of polyurethane microcapsules containing monocrotophos, which comprises of preparing a solution of diol or polyol having a molecular weight in the range of 200-2000, crosslinker, monocrotophos and a catalyst selected from amino or organometallic compounds; dispersing this solution into a dilute solution of stabilizer which consists of a block copolymer having the general formula ?A!.sub.n -?B!.sub.m where A and B are chemically and compositionally dissimilar segments where n and m segments are in between 30-115 and 10-60 units respectively, such that the sum of n and m does not exceed 175 units, in an aliphatic hydrocarbon; adding an isocyanate dropwise to this dispersion; agitating the mixture at 1000-1400 revolutions per minute for the first 6-8 hours and then at 500-800 revolutions per minute for an additional period of 14-18 hours at a temperature between 30.degree. to 40.degree. C.

Abstract: The invention relates to a process for the polymerization and co-polymerization of olefins, which comprises polymerizing/copolymerizing olefins in presence of a solvent, a supported metallocene catalyst and an aluminoxane as cocatalyst in a hydrocarbon medium, at a temperature in the range of 50 to 150.degree. C., at a pressure ranging between 1 to 20 bar, for a period of 10 minutes to 10 hours, scavenging the reaction mixture by addition of an organoaluminum compound to remove the last traces of impurities of solvent, separating the polymer by conventional method like, washing the polymer with an organic solvent and drying the polymer to remove the solvent to obtain the product.

Abstract: Crystallization of precursor polycarbonates prior to solid state polymerization is achieved by contact with a non-solvent comprising, at least in part, a dialkyl carbonate such as dimethyl carbonate. The non-solvent can be a mixture, typically of dimethyl carbonate with water or an alkanol such as methanol.

Abstract: The invention provides a process for the preparation of polyurethane microspheres, which comprises of preparing a solution of diol or polyol having a molecular weight in the range of 200-2000, crosslinker and a catalyst selected from amino or organometallic compounds, dispersing, this solution in dilute solution of stabilizer which consists of a block copolymer having the general formula ?A!.sub.n -?B!.sub.m where A and B are chemically and compositionally dissimilar segments and n and m segments are in between 30-115 and 10-60 units respectively, such that the sum of n and m does not exceed 175 units, in an aliphatic hydrocarbon, adding an isocyanate dropwise to this dispersion agitating the mixture at high speed of 100-1200 revolutions per minute, a temperature between 30.degree. to 55.degree. C. to permit the formation of polyurethane microspheres, separating these microspheres by filtration, washing with lower aliphatic hydrocarbon and drying the microspheres under vacuun.

Abstract: The invention provides a process for the preparation of polyurethane microspheres, which comprises of preparing a solution of diol or polyol having a molecular weight in the range of 200-2000, crosslinker and a catalyst selected from amino or organometallic compounds, dispersing this solution in dilute solution of stabilizer which consists of a block copolymer having the general formula ?A!.sub.n-- ?B!.sub.m where A and B are chemically and compositionally dissimilar segments and n and m segments are in between 30-115 and 10-60 units respectively, such that the sum of n and m does not exceed 175 units, in an aliphatic hydrocarbon, adding an isocyanate dropwise to this dispersion, agitating the mixture at high speed of 100-1200 revolutions per minute, a temperature between 30.degree. to 55.degree. C. to permit the formation of polyurethane microspheres, separating these microspheres by filtration, washing with lower aliphatic hydrocarbon and drying the microspheres under vacuum.

Abstract: A process for the preparation of poly(arylcarbonate)s, relying on reaction of dialkyl carbonates with bisphenols and using selected organotin and oganotitanium catalysts. The process is preferably performed in a first step in which bisphenols and dialkyl carbonates are reacted using a catalyst to obtain an oligo(arylcarbonate). The oligo(arylcarbonate) then undergoes a post polycondensation in a second step, either by itself or with diphenyl carbonate. The second step also uses a catalyst. The process yields poly(arylcarbonate)s that are characteristically free of color and gel.

Abstract: Solid state polycarbonate formation comprises an initial step of converting a precursor polycarbonate to an enhanced crystallinity precursor polycarbonate and a second step of polymerizing said enhanced crystallinity precursor polycarbonate in the solid state. Several options are employed. These include modifying the precursor polycarbonate by contact with a dihydroxy compound or diaryl carbonate, conversion of the precursor polycarbonate to the enhanced crystallinity polymer by contact with at least one compound selected from the group consisting of alkali metal hydroxides, tetraalkylammonium hydroxides, tetraalkylammonium carboxylates, tetraalkylphosphonium hydroxides and tetraalkylphosphonium carboxylates, and conducting the solid state polymerization in the presence of a catalytic amount of at least one tetralkylammonium or tetraalkylphosphonium carboxylate. The preferred tetralkylammonium compounds are tetramethylammonium maleate and tetramethylammonium hydroxide.

Abstract: An improved process for the preparation of aromatic polyesters, whereby dialkyl esters of aromatic dicarboxylic acids are melt-polymerized with aromatic bisphenol to furnish an amorphous poly(arylester) prepolymer. The amorphous poly(arylester) prepolymer is crystallized, separated, and dried to provide a crystallized poly(arylester) prepolymer, which is heated to yield the aromatic polyester.

Abstract: This invention involves a novel process for preparing branched polycarbonates employing a solid state polycondensation process; specifically, subjecting a linear crystallized oligomer derived from dihydroxydiaryl compound and a diaryl carbonate to solid state polycondensation process by heating the said oligomer at a temperature which is higher than the glass transition temperature but below its melting point in the presence of a multifunctional phenol and an alkali or alkaline metal salt or bisphenol or tetraalkylammonium hydroxide, carboxylate or bicarboxylate catalyst, the reaction being effected under inert atmosphere.

Abstract: Novel poly(arylester-carbonate)s of the formula ##STR1## are disclosed, as well a process for preparing such poly(arylester-carbonate)s.