摘要:
Expandable, rubber-modified styrene polymers for elastic polystyrene foams comprisea) a continuous phase comprising polystyrene or a styrene copolymer containing at most 50% of copolymerized comonomers andb) from 5 to 30% by weight of a butadiene-styrene block copolymer dispersed therein,and also a low-boiling blowing agent. The rubber particles have a compact lamellar structure without polystyrene inclusions. The expandable styrene polymers are prepared by polymerization of styrene in the presence of the block copolymer and impregnation with the blowing agent.
摘要:
In a process for the preparation of block copolymers from vinylaromatic monomers and dienes, the monomers are polymerized in the presence of at least one alkali metal organyl or alkali metal alkoxide and at least one magnesium, aluminum or zinc organyl.
摘要:
Thermoplastic molding compounds comprise as essential components A) from 10 to 100% by weight of copolymers of the monomers of the general formulae I and II ##STR1## where R.sub.1 is H or alkyl of 1-22 carbon atoms, R.sub.2 is H or alkyl of 1-22 carbon atoms, R.sub.3 is H or alkyl of 1-4 carbon atoms, a is 0, 1, 2, 3, 4 or 5, and b is 0, 1, 2, 3, 4 or 5, B) from 0 to 3000 ppm, based on the weight of component A, of compounds of the general formula I, C) from 0 to 500 ppm, based on the weight of component A, of compounds of the general formula II, D) from 0 to 90% by weight, based on the total weight of the molding compound, of polymers other than A), and E) from 0 to 50% by weight, based on the total weight of the molding compound, of additives and processing aids.
摘要:
Block copolymers comprise at least two hard blocks S1 and S2 made from vinylaromatic monomers and, between these, at least one random soft block B/S made from vinylaromatic monomers and from dienes, where the proportion of the hard blocks is above 40% by weight, based on the total block copolymer.
摘要:
A process for the reaction of an organic compound in the presence of a catalyst comprising, as active metal, ruthenium alone or together with at least one Group Ib, VIIb, or VIIIb metal in an amount of from 0.01 to 30 wt %, based on the total weight of the catalyst, applied to a support, wherein from 10 to 50% of the pore volume of the support comprises macropores having a pore diameter in the range of from 50 nm to 10,000 nm and from 50 to 90% of the pore volume of the support comprises mesopores having a pore diameter in the range of from 2 to 50 nm, the sum of said pore volumes being 100%, and said catalyst as such.
摘要:
In a process for the homopolymerization of vinylaromatic monomers or the copolymerization of vinylaromatic monomers and dienes in the presence of at least one alkali metal compound and at least one compound of an element of group 3a of the Periodic Table of the elements, the compounds contain, based on the sum of molar equivalents of alkali metal and elements of group 3a, in each case a) from 0.1 to 3.9 molar equivalents of oxygen, sulfur, nitrogen or phosphorus and b) from 0.1 to 3.9 molar equivalents of an organyl ligand.
摘要:
A process for the reaction of an organic compound in the presence of a catalyst comprising, as active metal, ruthenium alone or together with at least one Group Ib, VIIb, or VIIIb metal in an amount of from 0.01 to 30 wt %, based on the total weight of the catalyst, applied to a support, wherein from 10 to 50% of the pore volume of the support comprises macropores having a pore diameter in the range of from 50 nm to 10,000 nm and from 50 to 90% of the pore volume of the support comprises mesopores having a pore diameter in the range of from 2 to 50 nm, the sum of said pore volumes being 100%, and said catalyst as such.
摘要:
An elastomeric block copolymer comprising at least one block A having polymerized units of a vinylaromatic monomer and forming a rigid phase and at least one elastomeric block B/A having polymerized units of both vinylaromatic monomers and of a diene and forming a flexible phase, and glass transition temperature Tg of the block A being above 25.degree. C. and that of the block B/A being below 25.degree. C. and the phase volume ratio of block A to block B/A being chosen so that the amount of the rigid phase in the total block copolymer is 1 to 40% by volume and the amount of the diene is less than 50% by weight.
摘要:
Abstract of the disclosure: A process is described for the continuous preparation of an impact-resistant molding material by anionic polymerization of styrene or another aromatic vinyl compound or mixtures thereof in the presence of a solvent and a block rubber, wherein the polymerization is carried out in at least 2 reaction vessels that together form a reactor cascade, the monomer stream being subdivided among the reaction vessels present, the living polymer chain ends being terminated in a conventional manner and the solvent being removed.