Abstract:
There is disclosed herein an improved process for the preparation of high molecular weight polyphenylene ethers by oxidatively coupling a di-ortho substituted phenolic precursor in a reaction vessel containing oxygen and a complex catalyst formed from a copper salt and either a primary, secondary or tertiary amine wherein in the presence of an aqueous phase a quaternary ammonium salt is employed to promote the rate of reaction.
Abstract:
A catalyst precursor comprised of a dry admixture of manganese carbonate and at least one material selected from among magnesium carbonate, basic magnesium carbonate and magnesium hydroxide. The precursor is calcinable at elevated temperatures to an activated catalyst which may be used in a process for the ortho-alkylation of phenolic compounds.
Abstract:
There are provided thermoplastic compositions comprising a polyphenylene ether and a rubber modified polystyrene resin having a discontinuous phase of polystyrene particles englobed in diene rubber membranes, the particles being between about 0.1 and 0.7 microns in diameter. Such compositions provide molded articles with substantial and unexpected improvements in impact resistance and ability to transmit light in comparison with known compositions of such rubber modified polystyrenes alone or those of other polystyrenes combined with polyphenylene ethers.
Abstract:
A novel process is described for the control of molecular weight in the preparation of polyphenylene oxide polymers. The process is based on the slow addition of additional amounts of a monomeric phenol to a polyphenylene oxide polymerization reaction mixture which comprises a main charge of a monomeric phenol, a polyphenylene oxide polymerization catalyst and a solvent, while continuing polymerization.
Abstract:
A novel process is provided for preparing a blend of rubber, a polyphenylene ether resin and an alkenyl aromatic addition polymer which comprises using an alkenyl aromatic monomer as a solvent for the oxidative coupling of a phenol to a polyphenylene ether resin and thereafter adding a rubber and polymerizing the mixture to form said blend of rubber, an alkenyl aromatic addition polymer and a polyphenylene ether resin.
Abstract:
An improved process is disclosed for preparing polyphenylene ethers in which a complexing agent selected from the group consisting of biguanide, di-o-tolylbiguanide, dicyanodiamide, and L-Arginine is employed to terminate the oxidative coupling reaction and facilitate the recovery of the polymer.