Abstract: Process for the polymerization of unsaturated vinyl and/or vinylidene monomers which comprises reacting one or more monomers in the presence of heterocyclic initiators having a nitrogen atom bound to an oxygen atom at a temperature ranging from 100 to 130° C.

Abstract: Process for the polymerization of unsaturated vinyl and/or vinylidene monomers which comprises reacting one or more monomers in the presence of heterocyclic initiators having a nitrogen atom bound to an oxygen atom at a temperature ranging from 100 to 130° C.

Abstract: A process for the preparation of mixed silica-zirconia sols and mixed oxides in spherical form, comprising mixing a silicon alkoxide with a solution of an inorganic zirconium salt in a low molecular weight polyol and subjecting the intermediate thus formed to acid hydrolysis in a water medium.

Abstract: A process for the preparation of alternated linear copolymers based on carbon monoxide and one or more compounds having an unsaturation of the alkenylic type comprises, reacting in a halogenated aromatic or aliphatic solvent the carbon monoxide and one or more compounds having an alkenylic unsaturation in the presence of a catalyst having general formula (I)?Pd(chel)(chel')!.sup.+ ?A.sup.- !wherein: chel represents a non-charged bidentate chelating agent, chel' represents the anion of an organic compound containing a double carbon--carbon bond co-ordinated via .pi. bond to palladium (Pd) and a carbanion bound via .sigma. bond to palladium which is co-ordinated to the metal as a bidentate chelating agent and A.sup.- is an anion of a non-esterifiable or almost non-esterifiable and non-coordinating acid.

Abstract: Linear alternating copolymers of carbon monoxide and at least one compound containing an alkenyl unsaturation are obtained by reaction between carbon monoxide and at least one compound containing an alkenyl unsaturation, in a solvent which is liquid under the operating conditions, in the presence of a preformed bischelated catalyst having general formula (I) active without cocatalysts:?Pd(chel)(chel')!.sup.++ ?A.sup.- !.sub.2 (I)wherein: chel and chel', the same or different, represent a nitrogenated or phosphorated bidentate chelating agent, and A.sup.- represents an essentially non-co-ordinating, non-esterifiable and non-labile anion selected from (3,5-(CF.sub.3).sub.2 -C.sub.6 H.sub.3).sub.4 B.sup.-, tetra(perfluorophenyl)borate B(C.sub.6 F.sub.5).sub.4.sup.- and Al(C.sub.6 F.sub.5).sub.4.sup.-.

Abstract: The preparation and use of organometallic complexes of Group III metals having the formula:Me(Ar)(AlX.sub.3 R).sub.3 (I)wherein Me, Ar, X and R are as defined herein, to stereospecifically polymerize unsaturated monomers is provided.

Abstract: An improved process is described for the preparation of alternating linear copolymers based on carbon monoxide and at least one compound containing an alkenyl unsaturation which comprises reacting in a liquid solvent under the operating conditions, a mixture of carbon monoxide and one or more compounds containing an alkenyl unsaturation in the presence of:(i) a catalyst having general formula (I)?Pd(chel) (chel') !.sup.++ ?A.sup.- !.sub.2 (I)wherein chel and chel' the same or different, represent a nitrogenated or phosphorated bidentate chelating agent, and A.sup.- represents an essentially non-coordinating, non esterifiable and non labile anion of an acid with pKa less than 2; and(ii) a cocatalyst having general formula (II)?chel"H.sup.+ !?A'.sup.- ! (II)wherein A'.sup.-, the same as or different from A.sup.-, has the same meaning defined above and chel" represents a nitrogenated bidentate chelating agent the same as or different from chel and chel'.

Abstract: An active catalyst in the preparation of alternating copolymers of olefins with carbon monoxide (CO) and consisting of:a) a metal salt of the group IB of the periodic table;b) a bidentate binder containing two nitrogen or phosphorous atoms capable of binding themselves to the metal atom by means of co-ordination bonds;c) a Lewis acid;d) optionally an oxidizing agent.The preparation of the catalyst is described together with its use in the alternating copolymerization of ethylene (C2) and/or other olefins with carbon monoxide.

Abstract: A catalytic system to polymerize diolefinic monomers consists of a lanthanide salt, an organometallic compound of a metal belonging to groups I, II and III of the periodic table of elements and an organometallic compound of boron. The polymers obtained are characterized in that they have a high degree of 1,4 chain units and ratio between 1.4-cis/1,4-trans units which can vary as desired, and also a narrow molecular weight distribution.

Abstract: Organometallic complexes of lanthanides with a well-defined stoichiometry which can be used in the stereospecific polymerization of unsaturated monomers, can be represented by the general formula:Me(Ar)(AlX.sub.3 R).sub.3 (1)wherein: Me represents a metal with atomic number 21, 39, or an atomic number of between 57 and 71, Ar represents benzene or a susbstituted benzene with from 1 to 3 alkyl groups containing from 1 to 10 carbon atoms, X is a halogen atom, whereas R is a linear, cyclic or branched alkyl radical containing from 1 to 12 carbon atoms;the preparation of the complexes is described together with their use in the stereospecific copolymerization of unsaturated monomers.

Abstract: A catalytic system to polymerize diolefinic monomers consists of a lanthanide salt, an organometallic compound of a metal belonging to groups I, II and III of the periodic table of elements and an organometallic compound of boron. The polymers obtained are characterized in that they have a high degree of 1,4 chain units and ratio between 1.4-cis/1,4-trans units which can vary as desired, and also a narrow molecular weight distribution.

Abstract: An active catalyst in the preparation of alternating copolymers of olefins with carbon monoxide (CO) and consisting of:a) a metal salt of the group IB of the periodic table;b) a bidentate binder containing two nitrogen or phosphorous atoms capable of binding themselves to the metal atom by means of co-ordination bonds;c) a Lewis acid;d) optionally an oxidizing agent.The preparation of the catalyst is described together with its use in the alternating copolymerization of ethylene (C2) and/or other olefins with carbon monoxide.

Abstract: Organometallic complexes of lanthanides with a well-defined stoichiometry which can be used in the stereospecific polymerization of unsaturated monomers, can be represented by the general formula:Me(OR).sub.3 *(Me.sub.1 R.sup.1 R.sup.2 R.sup.3).sub.xwherein, Me represents a metal with atomic number 21, 39, or an atomic number between 57 and 71, OR is an alkoxylic group of an alcohol; Me represents a metal of the group IIIA, whereas R.sup.1, R.sup.2, R.sup.3 can be H, or a linear, branched or cyclo-aliphatic alkyl radical containing from 1 to 10 carbon atoms and x is an integer (3 or 4) and depends on the type of alkoxide used.The preparation of the complexes is described and their use in the stereospecific polymerization of unsaturated monomers.

Abstract: A catalyst active in the preparation of alternating olefin/carbon monoxide (CO) copolymers is constituted by:(a) Pd(O.sub.2 CNEt.sub.2).sub.2 (NHET.sub.2).sub.2 supported on a solid carrier preferably constituted by hydroxylated silica,(b) an either mono- or bidentate ligand containing one or two nitrogen or phosphorous atoms capable of linking to Pd atom by dative bonds,(c) a mineral or organic acid.Disclosed are the preparation of the catalyst and the use of said catalyst in alternated copolymerization of ethylene (C2) and/or other olefins with carbon monoxide (CO).

Abstract: Double-component acrylic adhesive compositions are disclosed, in which:(a) the adhesive component comprises a mono-functional acrylic monomer, a loro-sulfonated polyolefin and a crosslinker selected from difunctional silicon derivatives;(b) the activating component is a typical aldehyde-amine condensation product.

Abstract: A mixed-matrix composite material reinforced with continuous fibre comprising a flexible sheath of thermoplastic polymer covering a multifibre filament impregnated with a powder consisting of:1-99% by weight, and preferably 50-95%, of a thermoplastic polymer;99-1% by weight, and preferably 50-5%, of a reactive monomer and/or prepolymer which on thermal stressing is able to undergo crosslinking and/or molecular weight increase.

Abstract: A mixed-matrix composite material reinforced with continuous fibre comprising a flexible sheath of thermoplastic polymer covering a multifibre filament impregnated with a powder consisting of:50-99% by weight, and preferably 70-95%, of a thermoplastic polymer;50-1% by weight, and preferably 30-5%, of a C.sub.2 -C.sub.4 olefin/carbon monoxide alternating polymer having an intrinsic viscosity exceeding 0.1 dl/g when measured in m-cresol at 100.degree. C.

Abstract: Polymers having a very good combination of chemical, mechanical and process properties, and particularly useable either alone or as mixtures, as high-tenacity thermoplastic polymer and as elastomers or elastomeric modifiers, contain, randomly distributed along their chain, repeating cycloketonic structural units having the following general formula (I): ##STR1## wherein: A represents a tetravalent aliphatic or cycloaliphatic, substituted or non-substituted moiety containing a total number of from 4 to 50, preferably from 4 to 20, carbon atoms.Such polymers can be prepared by means of a process which comprises reacting, in a liquid media, a polydiene containing adjacent structural units derived from the 1,4-cis polymerization of conjugated dienes, with carbon monoxide, in the presence of free radical generating compounds and, optionally, a compound capable of acting as a hydrogen donor.

Abstract: A catalyst active in the preparation of alternating olefin/carbon monoxide (CO) copolymers is constituted by:(a) at least one salt of a metal of Group IB of the Periodic System,(b) an either mono- or bidentate ligand containing one or two nitrogen or phosphorus atoms capable of linking to the copper, silver or gold atom by means of dative bonds,(c) a mineral or organic acid.Disclosed are the preparation of the catalyst and the use of said catalyst in alternated copolymerization of ethylene (C2) and/or other olefins with carbon monoxide.

Abstract: Maleimidic derivatives containing acrylic residues having the general formula (I): ##STR1## wherein R is equal to H, CH.sub.3 ; A represents a cycloalkyl radical containing from 5 to 10 carbon atoms or an aryl radical containing from 6 to 12 carbon atoms and with the acryloxy residue --[--OCOC(R).dbd.CH.sub.2 ] in an ortho, meta or para position. The compounds are useful as thermostabilizing agents in structural adhesives with an acrylic base.