摘要:
Disclosed are a process for the preparation of an initiator composition comprising an alkali metal organyl and an aluminum organyl and a process for the polymerization of anionically polymerizable monomers.
摘要:
Biodegradable polyesters P1 obtainable by reaction of a mixture consisting essentially of(a1) a mixture consisting essentially offrom 35 to 95 mol % of adipic acid or ester-forming derivatives thereof or mixtures thereof,from 5 to 65 mol % of terephthalic acid or ester-forming derivatives thereof or mixtures thereof, andfrom 0 to 5 mol % of a sulfonate compound,the sum of the individual mole percentages being 100 mol %, and(a2) a dihydroxy compound selected from the group consisting of C.sub.2 -C.sub.6 -alkanediols and C.sub.5 -C.sub.10 -cycloalkanediols,the molar ratio of (a1) to (a2) being chosen within the range from 0.4:1 to 1.5:1,with the proviso that the polyesters P1 have a molecular weight (M.sub.n) within the range from 5000 to 50,000 g/mol, a viscosity number within the range from 30 to 350 g/ml (measured in 50:50 w/w dichlorobenzene/phenol at a concentration of 0.5% by weight of polyester P1 at 25.degree. C.) and a melting point within the range from 50 to 170.degree. C. and with the further proviso that the polyesters P1 are prepared using from 0.01 to 5 mol %, based on the molar quantity used of component (a1), of a compound D having at least three groups capable of ester formation,and further biodegradable polymers and thermoplastic molding compositions, processes for the preparation thereof, use thereof for producing biodegradable moldings, and adhesives, biodegradable moldings, foams and blends with starch obtainable from the polymers or molding compositions of the present invention.
摘要:
Ethene polymers are prepared by Phillips catalysis using (1) a supported catalyst which is loaded with chromium and titanium and (2) a co-catalyst, (1) having been obtained by preparing (1.1) a chromium- and titanium-loaded catalyst intermediate from (1.1.a) a silicate carrier material, (1.1.b) a selected chromium compound and (1.1.c) a selected titanium compound and then (1.2) heating said catalyst intermediate in an oxygen-containing gas stream, the (1) used having been obtained by, in general terms, (1.1) preparing in the first stage (1.1.1) a suspension from (1.1.1.1) a finely divided silicate carrier material and (1.1.1.2) a liquid alkane, (1.1.2) then (1.1.2.1) combining the suspension resulting from (1.1.1.) with (1.1.2.2.) a finely divided chromium trioxide, (1.1.3) thereupon (1.1.3.1) combining the suspension obtained from (1.1.2) with (1.1.3.2) an alkanol, (1.1.4) thereafter (1.1.4.1) combining the suspension formed in (1.1.3) with (1.1.4.2) a titanium compound of the formula Ti(OR).sub.4, where R is alkyl, aryl or cycloalkyl, and (1.1.5) finally evaporating the suspension obtained in (1.1.4) to dryness, and then (1.2) in the second stage first (1.2.1) treating the catalyst intermediate obtained in the first state (1.1) with a nitrogen stream, thereupon (1.2.2) heating the intermediate obtained in (1.2.1) in an oxygen-containing gas stream, and finally (1.2.3) treating the intermediate obtained in (1.2.2) with a nitrogen stream; and as (2) with an alkyllithium.
摘要:
A transition metal catalyst component (1) for Ziegler catalyst systems is prepared by (1.1) first combining (1.1.1) an inorganic oxidic substance (I), as the carrier, with (1.1.2) a solution (II) consisting of (IIa) an organic solvent and (IIb) a transition metal composition to form a suspension (III), evaporating down this suspension to form a solid-phase intermediate (IV) and (1.2) then combining (1.2.1) the solid-phase intermediate (IV) obtained from (1.1) with (1.2.2) a solution of an organoaluminum compound (V) to form a suspension, the resulting suspended solid-phase products (VI) being the transition metal catalyst component (1).The characteristic feature is that the solution (II) employed in stage (1.1) consists of (IIa) a certain oxahydrocarbon and (IIb) a mixture of (IIb1) a vanadium trichloride/alcohol complex, (IIb2) a titanium trihalide and (IIb3) a zirconium tetrahalide.
摘要:
A process for producing an activated monomer composition comprising at least one lactam and/or lactone, one catalyst, and one activator permits storage of the resultant monomer composition, since this is stable with respect to polymerization. Said monomer composition is used inter alia in producing a polyamide molding via ring-opening, anionic polymerization.
摘要:
The invention relates to a flameproofed resilient block polymer comprising polymerized units of at least one vinylaromatic monomer and at least one diene monomer with at least one flameproofing agent B) which comprises a compound comprising phosphorus, in particular a phosphorus-containing melamine compound, a process for the preparation and the use for the production of moldings.
摘要:
Process for preparation of block polymers of polyethylene terephthalate and of the polyamide composed of meta-xylylenediamine and adipic acid, and process for their preparation.
摘要:
Modified open-cell foams having a density in the range from 5 to 1000 kg/m3, a mean pore diameter in the range from 1 μm to 1 mm, a BET surface area in the range from 0.1 to 50 m2/g and an acoustic absorption factor of more than 50% at a frequency of 2000 Hz at a layer thickness of 50 mm, comprising in the range from 1 to 4000 ppm, based on the weight of the unmodified open-cell foam, fixed particles (b) having a mean diameter (number average) in the range from 5 nm to 900 nm.
摘要翻译:密度在5至1000kg / m 3的范围内的改性开孔泡沫,平均孔径在1μm至1mm的范围内,BET表面积在0.1 至50m 2 / g,在2000Hz的频率下,在50mm的层厚度下的声吸收系数大于50%,包括在1至4000ppm的范围内,基于 未改性的开孔泡沫体的重量,平均直径(数均)在5nm〜900nm范围内的固定粒子(b)。
摘要:
In a process for polymerizing dienes in a solvent comprising vinylaromatic monomers, the polymerization is carried out in the presence of a metal compound of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo or W as catalyst and a Lewis acid as cocatalyst and, if desired, an alkylating agent and, if desired, a regulator. This process can be used for preparing high-impact polystyrene, acrylonitrile-butadiene-styrene copolymers or methyl methacrylate-butadiene-styrene copolymers.