摘要:
The invention provides a method for a preparation of a polymer selected from the following: (a) modified interpolymer comprising, in polymerized form, a conjugated diene and an aromatic alpha-olefin, or (b) a modified polymer comprising, in polymerized form, a conjugated diene; and wherein said method comprising at least the following steps: polymerizing monomers comprising at least one conjugated diene monomer in at least one polymerization reactor, in the presence of at least one solvent, to form the polymer, optionally coupling a fraction of the polymer chains using at least one coupling agent, modifying the polymer with at least one modifying agent, in at least one reactor, in the presence of the at least one solvent, to form a modified polymer solution; optionally, contacting the modified polymer solution with at least one proton donating compound; contacting the modified polymer solution with water; removing the at least one solvent; contacting the removed solvent with at least one material that will react with, and/or adsorb, silanol to form a purified solvent, recirculating the purified solvent back to the at least one polymerization reactor or to a storage container.
摘要:
A polymer having at least the following characteristics: (a) a block styrene content with more than 4 consecutive styrene units from about 40 to about 70 weight percent based on total styrene content in the polymer; (b) a vinyl content from about 25 to about 80 weight percent based on total amount of polymerized 1,3-diene; (c) a styrene content from about 20 to about 75 weight percent based on total weight of polymer; and (d) a molecular weight distribution (Mw/Mn) of 1.5 or less.
摘要:
Provided is a process for preparing polystyrene having a weight average molecular weight (Mw) in the range of 120,000-160,000 g/mol, a polydispersity in the range of 4-6 and a melt flow rate of at least 40 g/10 minutes by feeding styrene into a reaction system through which the styrene passes as a component of a reaction mixture as it is polymerized, the reaction system including an initial reaction zone (100) and a downstream reaction zone (200), comprising the steps of: polymerizing styrene in the initial reaction zone to form polystyrene having a Mw of greater than 300,000 g/mol and a polydispersity in the range 1.5-2.5, 10-30 wt. % of the styrene fed to the initial reaction zone being polymerized there, —and polymerizing styrene remaining in the reaction mixture in the downstream reaction zone, a chain transfer agent being mixed with the reaction mixture at the commencement of this reaction zone and optionally at one or more additional locations within this reaction zone. The polystyrene may be used to manufacture expandable polystyrene beads or polystyrene foam board.
摘要:
Apparatus (1) for admixing additives to a medium to be pumped, comprising at least one gear pump (2) for pumping a medium to be pumped, said gear pump (2) comprising at least one shaft (3) having a first driving torque; at least one injector (5) for introducing an additive into a medium to be pumped; at least one screw conveyor (6) for mixing said additive with said medium to be pumped, said screw conveyor having a second driving torque, and, characterized in that, the shaft (3) and the screw conveyor (6) are functionally connected, such that the first driving torque and the second driving torque are coupled.
摘要:
An extruded polycarbonate multi-walled sheet structure includes at least two and in some cases seven or more generally parallel spaced apart walls and a plurality of ribs extending the length of the sheet in a direction of extrusion and separating adjacent walls. The sheet structure has a total thickness greater than 40 mm and the polycarbonate has a melt viscosity ratio greater than about 4.5 measured at 260° C. wherein the melt viscosity ratio is a ratio of the viscosity at a shear rate of 100 s−1 to the viscosity at a shear rate of 0.1 s−1.
摘要:
A method for increasing the monomer conversion in a redox initiated emulsion polymerization has been discovered. The method comprises adding a composition comprising an effective amount of a substituted phenol to the polymerization medium. In this manner, high monomer conversion is obtained and the product has low gel contents and a low amount or no crosslinking.
摘要:
The present invention relates to an improved process for online measurement of monomer concentration, specifically bisphenol A, in an interfacial polycarbonate manufacturing process. Wherein the measurement is obtained by vibrational spectroscopy for the purpose of improving process control, specifically, controlling the carbonate polymer molecular weight.
摘要:
A method for melt-processing a polymer of a monovinyl aromatic compound, such as styrene, is disclosed. The method may include heating a polymer of a monovinyl aromatic compound volumetrically with microwave energy, wherein the polymer of a monovinyl aromatic compound includes: a discontinuous rubber phase; and a continuous poly(monovinyl aromatic) phase comprising up to 49 weight percent of at least one of an acrylate comonomer and a vinyl cyanide comonomer.
摘要:
Metal complexes, catalyst compositions containing the metal complexes, and processes for making the metal complexes and the catalyst compositions are described for the manufacture of polymers from ethylenically unsaturated addition polymerizable monomers. The metal complexes have chemical structures corresponding to one of the following formulae: wherein MI and MII are metals; T is nitrogen or phosphorus; P is a carbon, nitrogen or phosphorus atom; groups R1, R2 and R3 may be linked to each other; Y is a divalent bridging group; X, X1, and X2 are anionic ligand groups with certain exceptions; D is a neutral Lewis base ligand; and s, o, k, i, ii, p, m, a, b, c, d, e, t, and y are numbers as further described in the claims.
摘要:
An improved seating system that includes a blow molded seat back assembly that is fabricated to include a seat back comprising a double walled design having a foreword (14) and a rearward (16) wall wherein there is at least one or more sections comprising a single wall (213). Further, the blow molded seat back may include an integrated reinforcement structure.