Abstract: Lanthanide and actinide catalyst systems normally appear to be "pseudo-living" when they are used to polymerize conjugated diolefin monomers into polymers. Polymerizations which are catalyzed with such catalyst systems produce polymers which have increasingly high molecular weight as monomer conversions are increased. Consequently, any change in polymerization time or conversion may affect the polymer's ultimate molecular weight. This has made controlling the molecular weight of polymers which are made utilizing lanthanide and actinide catalysts difficult.It has been unexpectedly discovered that vinyl halides can be used as molecular weight regulators for polymerizations which are catalyzed with lanthanide and actinide catalyst systems.

Abstract: Process for the production of polyphenyleneoxide, in which:oxygen, or a gas containing molecular oxygen is fed into a liquid reaction medium, solvent of the 2,6-xylenol and of the catalyst cupric salt complexed with an organic base, but nor solvent or substantially not solvent of the polyphenyleneoxide;from time to time samples are collected of the reaction mixture, said samples are treated with a liquid solvent, capable of dissolving polyphenyleneoxide and of stopping the growth of the macromolecules, until a clear and homogeneous solution is obtained;the through time of the so obtained solution is measured in a capillary tube viscometer and the value is determined of the viscosity and/of the molecular weight of polyphenyleneoxide by the comparison with standard values; andon the basis of the so determined value of the viscosity and/or of the polyphenyleneoxide molecular weight interventions are effected on the oxidative polymerizing reaction of 2,6-xylenol.

Abstract: Novel polyacetylene films are disclosed, having the following properties:elongation at break (1/10): higher than 4tensile strength: higher than 100 MPaability of attaining under stretch high levels of molecular orientation in the direction of pull.The process for preparing such polyacetylene films is also described.

Abstract: Polymers of caprolactam, having high impact strength, obtained by means of anionic polymerization, containing a rubbery phase distributed homogeneously inside the polymer consisting of alternating copolyesteramides with elastomeric properties, and a related production process, comprising dissolving or swelling the elastomeric phase in monomer caprolactam, and submitting the mixture to a polymerization at temperatures variable within the range of from 120.degree. C. to 180.degree. C., in the presence of a basic initiator, and of an activator.

Abstract: A process for preparing quaternary ammonium hydroxides by electrolysis in an electrolytic cell comprising two compartments, namely an anode and a cathode compartment, separated by an anion exchange permselective membrane, starting from quaternary ammonium halides.

Abstract: A raw 2,6-xylenol product is purified by melting it, then slowly and uniformly cooling it until at least 60 to 100% is crystallized, with the greater concentration of the impurities being present nearer the surface of the resulting crystals, gradually heating the crystalline solid mass to an elevated temperature no higher than by 0.1.degree. to 5.degree. C. below the solidification temperature of 2,6-xylenol to cause only surface melting of the crystals, thus yielding a molten liquid phase and a solid crystalline phase, the solid phase containing 2,6-xylenol in greater purity than the molten phase.

Abstract: Preparation of alkylation catalysts containing iron oxide and/or chromium oxide, by means of a process which comprises:(a) precipitating hydrate oxides of iron and/or chromium from an aqueous solution of soluble compounds of said elements;(b) separating the thus obtained precipitate, and washing said precipitate;(c) granulating the washed precipitate, and drying the granules so obtained;(d) calcining said dried granules at high temperature;in which an organic carboxylic acid salt of iron and/or chromium is added to and homogenized with the washed precipitate from stage (b), and/or the dried granules from stage (c) are impregnated with an aqueous solution of an organic carboxylic acid salt of iron and/or chromium.The catalysts obtained by means of the above process are mechanically strong, and highly active in the production process of 2,6-xylenol by means of the alkylation of phenol or o-cresol with methanol.

Abstract: Process for the production of polyphenylene oxide by means of the oxidative polymerization of 2,6-xylenol, with either oxygen or a gas containing molecular oxygen, in the presence of a catalyst, by continuously operating in a circulation system, and with the precipitation of the polymer in the liquid reaction medium.

Abstract: A polymerizable liquid composition is disclosed, intended for preparing polymerizates having outstanding optical and physical properties, said composition consisting of a bis (allylcarbonate) of a dihydric alcohol oligomer, a bis (allylcarbonate) monomer of a dihydric or a trihydric alcohol, or an allyl ester, or a triallyl cyanurate or isocyanurate, and an acrylic or vinylic monomer, said composition being polymerized in bulk with the aid of at least one radicalic initiator. Highly transparent articles are obtained, which are very useful for fine optical applications.

Abstract: Process for the production of alkyl isocyanates which can be defined by the general formula: R--N.dbd.C.dbd.O wherein R is an alkyl radical having from 1 to 4 carbon atoms by thermal decomposition of phenyl-N-alkyl urethans which can be defined by the general formula: ##STR1## wherein R has the above defined meaning. Said thermal decomposition is carried out without any substance having a catalytic activity being present in the decomposition reaction, by heating to a temperature of from 180.degree. C. to 210.degree. C. under the atmospherical pressure or a slightly reduced pressure, a mixture of phenol and phenyl-N-alkyl urethan, in a molar ratio of the former to the latter equal to or nearly equal to 1:1, removing by vaporization the phenol and the alkyl isocyanate from said vaporized products and maintaining in the reaction mixture, substantially throughout the thermal decomposition a molar ratio of phenol to phenyl-N-alkyl urethan not lower than about 1:1.