Abstract: The present invention relates to biodegradable polymer mixtures comprising i) 40% to 95% by weight, based on the total weight of components i to ii, of at least one polyester based on aliphatic or aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds; ii) 5% to 60% by weight, based on the total weight of said components i to ii, of polyalkylene carbonate, particularly polypropylene carbonate; iii) 0% to 60% by weight, based on the total weight of said components i to iii, of at least one biodegradable homo- or copolyester selected from the group consisting of polylactic acid, polycaprolactone and polyhydroxyalkanoate, and/or of an inorganic or organic filler; iv) 0% to 10% by weight, based on the total weight of said components i to ii, of an epoxy-containing copolymer based on styrene, acrylic ester and/or methacrylic ester, and v) 0% to 15% by weight of an additive selected from the group consisting of lubricant, antiblocking agent, antistat, UV absorber, UV stabilizer, thermal stabil

Abstract: Process for producing a polymer-graphite nanocomposite, which comprises the steps a) oxidation of graphite to graphite oxide, b) conversion of the graphite oxide into an aqueous dispersion, c) mixing of the aqueous dispersion comprising graphite oxide or, if appropriate, reduced graphite oxide which is obtained from b) with an aqueous polymer dispersion comprising at least one polymer and d) separating off the polymer-graphite mixture from the aqueous phase, wherein the graphite oxide which has been oxidized in step a) is reduced to graphite between step b) and c) or between step c) and d).

Abstract: The present invention relates to biodegradable polymer mixtures comprising i) 40% to 95% by weight, based on the total weight of components i to ii, of at least one polyester based on aliphatic or aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds; ii) 5% to 60% by weight, based on the total weight of said components i to ii, of polyalkylene carbonate, particularly polypropylene carbonate; iii) 0% to 60% by weight, based on the total weight of said components i to iii, of at least one biodegradable homo- or copolyester selected from the group consisting of polylactic acid, polycaprolactone and polyhydroxyalkanoate, and/or of an inorganic or organic filler; iv) 0% to 10% by weight, based on the total weight of said components i to ii, of an epoxy-containing copolymer based on styrene, acrylic ester and/or methacrylic ester, and v) 0% to 15% by weight of an additive selected from the group consisting of lubricant, antiblocking agent, antistat, UV absorber, UV stabilizer, thermal stab

Abstract: The present invention relates to biodegradable polymer mixtures comprising i) 40% to 95% by weight, based on the total weight of components i to ii, of at least one polyester based on aliphatic or aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds; ii) 5% to 60% by weight, based on the total weight of said components i to ii, of polyalkylene carbonate, particularly polypropylene carbonate; iii) 0% to 60% by weight, based on the total weight of said components i to iii, of at least one biodegradable homo- or copolyester selected from the group consisting of polylactic acid, polycaprolactone and polyhydroxyalkanoate, and/or of an inorganic or organic filler; iv) 0% to 10% by weight, based on the total weight of said components i to ii, of an epoxy-containing copolymer based on styrene, acrylic ester and/or methacrylic ester, and v) 0% to 15% by weight of an additive selected from the group consisting of lubricant, antiblocking agent, antistat, UV absorber, UV stabilizer, thermal stabil

Abstract: Process for producing a polymer-graphite nanocomposite, which comprises the steps a) oxidation of graphite to graphite oxide, b) conversion of the graphite oxide into an aqueous dispersion, c) mixing of the aqueous dispersion comprising graphite oxide or, if appropriate, reduced graphite oxide which is obtained from b) with an aqueous polymer dispersion comprising at least one polymer and d) separating off the polymer-graphite mixture from the aqueous phase, wherein the graphite oxide which has been oxidized in step a) is reduced to graphite between step b) and c) or between step c) and d).

Abstract: The present invention relates to a process for the production of polymer mixtures of i) polypropylene carbonate and ii) at least one further polymer, including the following steps: (a) reaction of propylene carbonate with carbon dioxide in the presence of a zinc catalyst, cobalt catalyst, or lanthanoid catalyst—in excess propylene carbonate or in an aprotic non-water-miscible solvent, (b) addition of an aqueous acidic solution to the reaction mixture after termination of the reaction, (c) removal of the aqueous phase, (d) optionally washing of the remaining organic phase with water, (e) addition of polymer component ii), (f) degassing and drying of the resultant polymer mixture and optionally removal of the aprotic, non-water-miscible solvent, and (g) pelletization of the polymer melt.

Abstract: Zinc salts of C4-8-alkanedicarboxylic acids, obtainable by reacting C4-8-alkanedicarboxylic acids with surface-modified zinc oxide particles, said surface-modified zinc oxide particles being obtainable by treatment of zinc oxide particles with organosilanes, silazanes and/or polysiloxanes and subsequent heat treatment and/or UV irradiation of treated zinc oxide particles, and the use thereof as polymerization catalysts for the preparation of polyalkylene carbonates.

Abstract: Production of polyalkylene carbonates via polymerization of carbon dioxide with at least one epoxide of the general formula (I): where R re mutually independently H, halogen, NO2, CN, COOR? or C1-20-hydrocarbon moiety, which can have substitution, where one of the moieties R can also be OH, and where two moieties R can together form a C3-5-alkylene moiety, R? is H or C1-20-hydrocarbon moiety, which can have substitution; n a zinc salt of C4-8-alkanedicarboxylic acids as catalysts, where a carboxylic acid or an acidic ion exchanger and a non-water-miscible organic solvent which dissolves the polyalkylene carbonate are admixed with the reaction mixture obtained after the reaction, and the organic phase is washed with water, and the polyalkylene carbonate is optionally obtained from the organic phase.

Abstract: A process is described for preparing polyoxymethylene by contacting a formaldehyde source with a catalyst of the formula I [ML1aL2b]cm+Zc·m/nn???(I) where M is a metal of group VIII; L1 is a ligand having at least one ?-electron pair; each L2 is independently tetrahydrofuran or a ligand which is displaceable by tetrahydrofuran; Z is an anion; a is 1 or 2; b is an integer from 0 to 4; c is 1 or 2; and m and n are integers from 1 to 4.

Abstract: A process is described for preparing polyoxymethylene by contacting a formaldehyde source with a catalyst of the formula I [CpvMLw]m+Zm/nn???(I) where M is Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh or Ir, Cp is a cyclopentadienyl ligand C5H(5-u)R1u, where u is from 0 to 5 and R1 is alkyl, alkenyl, aryl, heteroaryl, aralkyl, COOR2, COR2, CN or NO2, and R2 is H, alkyl, aryl or aralkyl, v is 1 or 2, each L is independently a nitrile, CO or a ligand displaceable by CO, w is an integer from 0 to 4, Z is an anion, and m and n are each independently an integer from 1 to 3.

Abstract: A process is described for preparing polyoxymethylene by contacting a formaldehyde source with a catalyst of the formula I [ML1aL2b]cm+Zc·m/nn???(I) where M is a metal of group VIII; L1 is a ligand having at least one ?-electron pair; each L2 is independently tetrahydrofuran or a ligand which is displaceable by tetrahydrofuran; Z is an anion; a is 1 or 2; b is an integer from 0 to 4; c is 1 or 2; and m and n are integers from 1 to 4.

Abstract: A process for preparing stabilized olefin polymers which have a low cold heptane extractables content by polymerization of olefins with Ziegler or Phillips catalysts, wherein the polymer is, immediately after leaving the polymerization reactor, brought into contact with an involatile phenol derivative.

Abstract: Polymerizable alkanes are prepared by gas-phase polymerization in the presence of catalyst systems by a process in which the catalyst systems used are supported castalyst systems.

Abstract: Supported catalyst systems are obtainable by A) reaction of an inorganic carrier with a metal compound of the general formula I M1(R1)r(R2)s(R3)t(R4)u  I  where M1 is an alkali metal, an alkaline earth metal or a metal of main group III or IV of the Periodic Table, R1 is hydrogen, Ch1-C10-alkyl, C6-C15-aryl, alkylaryl or arylalkyl each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, R2 to R4 are each hydrogen, halogen, C1-C10-alkyl, C6-C15-aryl, alkylaryl, arylalkyl, alkoxy or dialkylamino each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, r is an integer from 1 to 4 and s, t and u are integers from 0 to 3 the sum r+s+t+u corresponding to the valency of M1, B) reaction of the material obtained according to A) with a metallocene complex in its metal dihalide form and a compound forming metallocenium ions and C) subsequent reaction with a metal compound of the general formula I

Abstract: Polymers of alkenes are prepared by suspension polymerization in the presence of catalyst systems by a process in which the catalyst systems used are supported catalyst systems obtainable by A) reaction of an inorganic carrier with a metal compound of the general formula I M1(R1)r(R2)s(R3 )t(R4 )u  I where M1 is an alkali metal, an alkaline earth metal or a metal of main group III or IV of the Periodic Table, R1 to R7 are variously halogen, alkoxy, dialkylamino, hydrogen, C1-C10-alkyl, C6-C15-aryl, alkylaryl or arylalkyl each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, r, s, t and u are integers from 1 to 4 the sum r+s+t+u corresponding to the valency of M1, B) reaction of the material obtained according to A) with a metallocene complex in its metal dihalide form and a compound forming metallocenium ions and C) subsequent reaction with a metal compound of the general formula II M2(R5)o(R6)p(R7)q  II.

Abstract: Polymers of alkenes are prepared by suspension polymerization in the presence of catalyst systems by a process in which the catalyst systems used are supported catalyst systems obtainable by

Abstract: Supported catalyst systems are obtainable bya) application of a mixture ofA) at least one metallocene complex andB) at elast one metal compoundto a carrier which, if required, may have been pretreated, andb) subsequent activation by reaction with a solution or suspension of a compound forming metallocenium ions.

Abstract: Transition metal complexes of the formula IL.sub.m MX.sub.n I,whereL is a ligand of the formula II ##STR1## m is 1 or 2, M is a titanium, zirconium, hafnium, vanadium, niobium, tantalum, or a rare earth metal,X is fluorine, chlorine, bromine, iodine, hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl or OR.sup.1,n is 1, 2, 3, or 4 as defined herein, andR.sup.1, R.sup.2, R.sup.3, R.sup.4, and A are as defined herein,and the use of these complexes as catalysts for olefin polymerization are described herein.

Abstract: Molding compositions are based on polymers of ethylene made from(A) from 40 to 65% by weight of an ethylene polymer having a density in the range from 0.948 to 0.964 g/cm.sup.3, a melt flow index (MFI) of from 6 to 20 g/10 min and a mean molar mass distribution M.sub.w /M.sub.n in the range from 2 to 5,(B) from 35 to 60% by weight of an ethylene polymer having a density in the range from 0.935 to 0.953 g/cm.sup.3, a melt flow index (MFI) of from 0.1 to 0.35 g/10 min and a mean molar mass distribution M.sub.w /M.sub.n in the range from 6 to 20, and(C) from 0 to 6% by weight of the usual additives for thermoplastics,where the density of the molding compositions is in the range from 0.948 to 0.957 g/cm.sup.3, the melt flow index is in the range from 1.0 to 2.0 g/10 min, the mean molar mass distribution M.sub.w /M.sub.n is in the range from 3 to 10 and the difference of the densities of components A and B (.DELTA.D=D.sub.(A) -D.sub.(B)) is in the range from 0 to 0.029 g/cm.sup.3.

Abstract: Homopolymers of ethylene or copolymers of ethylene with other olefins or mixtures thereof are prepared by suspension polymerization in the presence of catalyst systems by a process in which the catalyst systems used are those which contain, as active components,A) a finely divided carrier treated with trialkylaluminum,B) a metallocene complex,C) an open-chain or cyclic alumoxane compound andD) an alkali metal alkyl or alkaline earth metal alkyl or a mixture thereof.