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: Sheet-like moldings or foils with anisotropic coefficients of thermal expansion are produced from extrudable thermoplastic polymer molding compositions by filling the thermoplastic polymer molding compositions with lamellar phyllosilicates whose diameter is in the range from 10 to 1000 nm and whose aspect ratio is in the range from 1:5 to 1:10 000 and extruding the filled thermoplastic polymer molding compositions, and then monoaxially or biaxially orienting the extrudate to give sheet-like moldings or foils.

Abstract: A process is proposed for preparing polymers filled with nanoscale metal oxides and comprises the following steps: a) preparing a nanosuspension of one or more crystalline metal oxides, hydroxides or oxide hydroxides by heating a suspension of one or more compounds comprising the corresponding metals in a first polymerizable compound to a temperature greater than the boiling point of water under process pressure and less than the boiling temperature of the first polymerizable compound and also less than the temperature at which the polymerization of the first polymerizable compound commences, ?in the presence of water in an amount corresponding to 1 to 10 oxygen atoms per metal atom of the compound or compounds comprising the corresponding metals, and b) polymerizing the first polymerizable compound under pressure and temperature conditions typical for the first polymerizable compound.

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 [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 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: Polyalk-1-enes are prepared by polymerization of alk-1-enes with the aid of the compound bis(cyclopentadienyl)-chromium(II) in which the cyclopentadienyl rings may carry inert organic radicals, said compound being adsorbed on an inorganic oxide carrier, by a process in which the polymerization is carried out in the presence of an organometallic compound of a metal of main groups I to III or of a metal hydride, in particular of n-butyl-lithium.

Abstract: A process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, in which(1) a silicon dioxide-containing support gel is prepared by(1.1) introducing a sodium water glass or potassium water glass solution into a swirling stream of an aqueous mineral acid longitudinally and tangentially to the stream, spraying the resultant silica hydrosol in drop form into a gaseous medium and allowing it to solidify to form a hydrogel, and freeing the resultant hydrogel from salts by washing without prior ageing,(1.2) drying the hydrogel resulting from (1.1) to form the support gel,(2) the support gel (1) is charged with chromium trioxide or a chromium compound which can be converted into chromium trioxide under the conditions of process step (3), giving a chromium-containing support gel, and(3) the chromium-containing support gel (2) is heated at from 400.degree. to 1100.degree. C.

Abstract: A process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, in which(1) a silicon dioxide-containing support gel is prepared by(1.1) introducing a sodium water glass or potassium water glass solution into a swirling stream of an aqueous mineral acid longitudinally and tangentially to the stream, spraying the resultant silica hydrosol in drop form into a gaseous medium and allowing it to solidify to form a hydrogel, and freeing the resultant hydrogel from salts by washing without prior ageing,(1.2) drying the hydrogel resulting from (1.1) to form the support gel,(2) the support gel (1) is charged with chromium trioxide or a chromium compound which can be converted into chromium trioxide under the conditions of process step (3), giving a chromium-containing support gel, and(3) the chromium-containing support gel (2) is heated at from 400.degree. to 1100.degree. C.