Abstract: Stable dispersions of polyols having a viscosity lower than 10,000 mPa.times.sec and containing dispersed particles of polyvinylchloride, having a size within the range of from 1 to 10 micrometers and impregnated by the said polyols.

Abstract: A process for oxidizing fluorinated olefins to the corresponding epoxides by reacting a fluoroolefin with oxygen in a concentration, in the reaction mixture, ranging from 1 to 60% by volume, at a temperature up to 250.degree. C. and in the presence of a catalyst consisting of porous silicon dioxide in a crystalline form, with a high purity degree and carrying metal oxides of the first transition series, or copper oxides or lanthanide oxides or mixtures thereof.

Abstract: Polyisocyanate compositions comprising:(a) from 90 to 50% by weight of the reaction product between an organic diisocyanate and a polyether-polyol of functionality of at least 2, and wherein said reaction product has a content of free NCO radicals within the range of from 26.5 to 33% by weight; and(b) from 10 to 50% by weight of polymethylene-polyphenyl-polyisocyanates.

Abstract: Blends based on vinyl-aromatic polymers having high tenacity and impact strength, comprising:a vinyl-aromatic copolymer containing from 2 to 25% by weight of an ethylenically unsaturated nitrile and a rubber amount not higher than 15% by weight; anda grafted polymer consisting of an elastomeric core having a transition temperature of the second order lower than 10.degree. C. containing, in the grafted form, chains of vinyl monomers.

Abstract: The present invention relates to a method of preparing a catalyst for the ammoximation of carboxylic compounds, consisting of a synthetic, crystaline and porous material based on silicon and titanium oxides, characterized in that a preformed matrix of amorphous silica is impregnated with an aqueous solution, containing a titanium compound and an organic compound of nitrogen, as a templating agent, and that to the thus impregnated material a zeolitic structure is given by means of a hydrothermal synthesis of usual type, shape and size of the matrix being substantially maintained unchanged.

Abstract: A thin-layer evaporator particularly suited for treating high-viscosity fluids, including a treating chamber surrounded by a heating or cooling shell, and a rotor equipped with feed and thrust elements. The feed and thrust elements include at least two axial, equidistant and staggered rows of blade members having the same pitch and sloping with respect both to the rotor axis and to the axial plane passing through their connection line; each member being offset, with respect to the members of the adjacent rows, by a space equal to the half pitch of the member.

Abstract: A polymeric blend based on vinyl-aromatic polymers having high impact resistance and including a thermoplastic polyurethane, a vinyl-aromatic copolymer containing an ethylenically unsaturated nitrile and a rubber, and a vinyl aromatic polymer, all present in specified amounts.

Abstract: The invention concerns a catalytic process for the manufacture of oximes by ammoximation of the corresponding carbonyl compounds, characterized in that the catalyst is a solid composition consisting of silicon, titanium and oxygen, chemically combined with each other, and in that the titanium amount, expressed as TiO.sub.2, ranges from 1 to 95% by weight, the XR diffractogam of said composition being a smooth-trend line (halo), typical of the amorphous solids.

Abstract: Soft and low-density foam materials, obtained by means of an extrusion expansion (with physical blowing agents) of particular copolymers of ethylene with vinylacetate (and/or with alkyl esters of acrylic or methacrylic acid), are found to be very suitable for the manufacture of expanded articles with little shrinkage after expansion, free from creases on the surface or cracks on the cell walls, and having excellent characteristics, higher compressive strength and so on.

Abstract: Selective thermodegradation of homo- and copolymers of propylene, without encountering thermo-oxidation phenomena, by treating the polymer at 250.degree.-350.degree. C. in the presence of primary and/or secondary antioxidant and of a derivative of benzopinacol having formula (I): ##STR1## wherein n=1, or=0, and when n=1, X may be=1, and in this case Z.sub.1 and Z.sub.2 form together with each other ##STR2## groups, ##STR3## wherein R.sub.1, R.sub.2, R.sub.3, which may be the same or different, are alkyl or aryl radicals;or X ranges from 3 to 20 and in this case Z.sub.1 and Z.sub.2 are aryl radicals, A and B are R.sub.1 -Si-R.sub.2 groups that are part of an oligomer having formula: ##STR4## and when n=0, X is=1, Z.sub.1 and Z.sub.

Abstract: Soft and low-density foam materials, obtained by means of an extrusion expansion (with physical blowing agents) of particular copolymers of ethylene with vinylacetate (and/or with alkyl esters of acrylic or methacrylic acid), are found to be very suitable for the manufacture of expanded articles with little shrinkage after expansion, free from creases on the surface or cracks on the cell walls, and having excellent characteristics, higher compressive strength and so on.

Abstract: Compositions comprising from 5 to 50% by weight of a polyphenylene ether and from 95 to 50% by weight of a styrene polymer having a syndiotactic structure. Such compositions are endowed with enhanced mechanical properties compared to those containing amorphous polystyrene, or polystyrene having an isotactic structure.

Abstract: A process for producing modified, impact-resistant polyamides showing an increased polymerization rate, which consists in polymerizing an .omega.-lactam in the presence of:(a) a mixture of an organic di-isocyanate and an organic mono-isocyanate, the isocyanate groups of both of which are blocked with an .omega.-lactam;(b) a poly-oxy-alkylene-amine having an aminic functionality lower than 3, and(c) an alkaline catalyst.

Abstract: Blends based on vinyl-aromatic polymers endowed with high tenacity and good chemical resistance, comprising:40 to 98% by weight of a vinyl-aromatic polymer containing from 0.5 to 5% by weight of a vinyl-aromatic monomer conjugated diene block copolymer;1-54% by weight of a polyolefine; and1-20% by weight of a vinyl-aromatic monomer-conjugated diene star block copolymer; the sum of the three components being equal to 100%.

Abstract: Process of preparing modified polyamides endowed with improved mechanical properties, which process resides in polymerizing an .omega.-lactam in the presence of(a) a polyisocyanate having the isocyanate groups blocked by an .omega.-lactam,(b) a poly-oxy-alkylene-amine, and(c) an alkali metal catalyst.A further object of the invention is the products obtained by means of such a process.

Abstract: Blends based on vinyl-aromatic polymers having high tenacity and impact strength, comprising:a vinyl-aromatic copolymer containing from 2 to 25% by weight of an ethylenically unsaturated nitrile and a rubber amount not higher than 15% by weight; anda grafted polymer consisting of an elastomeric core having a transition temperature of the second order lower than 10.degree. C. containing, in the grafted form, chains of vinyl monomers.

Abstract: Process for the imidization of vinyl-aromatic copolymers containing maleic anhydride, using as an imidizing agent an amide, the imidization being conducted in an anhydrous state and in the presence of a catalyst.

Abstract: Method for the non-destructive removal of tubes or of portions of tubes from heat exchangers, comprising:(a) the lengthwise cutting along at least one generatrix of one tube or of a plurality of tubes of said exchanger, to a depth at least equal to the thickness of the tube plate and to a width of up to 2% of the outer perimeter of the tubes;(b) the approaching to each other of the edges of the so-obtained cut section up to the complete release of the tube, or of the tubes, from the tube plate;(c) the possible crossways cutting of the tube, or of the tubes, to a height at least equal to double the thickness of the tube plate; and(d) the recovery of the tube, or of the tubes, by sliding same out of the said plate.

Abstract: Bimodal star-block copolymers are disclosed containing from 60 to 90% by weight of an aromatic vinyl monomer and from 40 to 10% by weight of a conjugated diene, said copolymers having the general formula:(S--S.sub.1 --B/S.sub.2 --B.sub.1).sub.m --X--(B.sub.1 --S.sub.2 /B--S.sub.1).sub.nwherein X is a polyfunctional radical, m and n are integers (being m.ltoreq.n) the sum of which is between 3 and 20 and equal to the functionality degree of the radical X, S and S.sub.1 are polymer blocks of an aromatic vinyl monomer, B.sub.1 is an elastomeric copolymer of conjugated dienic units, containing up to 20% of all the dienic units of the copolymer, and B/S.sub.2 and S.sub.2 /B are blocks of copolymers of aromatic vinyl monomer and conjugated diene of the random and/or tapered type.

Abstract: Process for the continuous production in solution of styrene thermoplastic resins by polymerization of a vinyl-aromatic monomer and of a vinyl-nitrile monomer in the presence of an elastomer and of a starter, wherein polymerization is conducted in two or more steps, wherein the elastomeric component is fed, in solution in the solvent and/or in the monomers, to the first step, polymerization is carried out in the subsequent steps at temperatures ranging from 70.degree. to 150.degree. C., in each step the reaction mass is gently and homogeneously stirred and the reaction product is caused to flow to a thin evaporator heated at 150.degree.-300.degree. C.