摘要:
Continuous process for preparing a halogenated polymer comprising a step of polymerization of at least one halogenated monomer in a medium comprising carbon dioxide in the liquid or supercritical state (L/SC-CO2), in at least one pressurized reactor, said process comprising at least : - (1) an expansion of the suspension resulting from the reactor; - (2) a separation of the expanded suspension resulting from the reactor into a first stream, containing the solid phase comprising the halogenated polymer and into a liquid, gaseous or supercritical second stream, which is a mixture Of CO2 and of monomer not converted to polymer; and the recovery of this first stream and of this second stream; - (3) an optional reheating, applied to the expanded suspension, before or after its separation into first and second streams, with optional recovery of the cold energy generated by the expansion; - (4) a recompression of the second stream and the optional cooling thereof in order to recycle it, at a plurality of points, to the reactor feed, with a fresh monomer make-up and, possibly, a CO2 make-up; - (5) a final step of degassing the halogenated polymer, optionally in combination with a continuous technique of forming the polymer into granules. Device for implementing the process.
摘要:
The invention relates to a process for the isolation of (per)fluorinated polymers containing sulfonyl fluoride functional groups from a polymerization latex. The process comprises adding the polymerization latex to an aqueous electrolyte solution under high shear stirring at a temperature equal to or lower than the glass transition temperature of the polymer. The invention further relates to the (per)fluorinated polymers containing sulfonyl fluoride functional groups isolated by the process and characterised by a loss of weight at 200° C. lower than 1% as determined by thermogravimetric analysis.
摘要:
The present invention is directed to provide a novel continuous polymerization apparatus which is able to more efficiently produce a polymer composition having a variety of properties. In a continuous polymerization apparatus at least two reactors (10, 20) of a complete mixing type are used. Each of the reactors (10, 20) is provided with a supply port (11a, 21a) and an effluent port (11b, 21b); the respective supply ports (11a, 21a) of the two reactors (10, 20) are commonly connected to a supply source (1, 3) of a raw material monomer and a polymerization initiator; a flow control valve (8) is installed on a raw material supply line (9) for supplying a mixture comprising the raw material monomer and the polymerization initiator from the supply source (1, 3) of the raw material monomer and the polymerization initiator to the respective supply ports (11a, 21a) of the two reactors (10, 20); and the respective effluent ports (11b, 21b) of the two reactors (10, 20) are connected to a common effluent line (27).
摘要:
Disclosed is a method for preparing copolymers of styrene and maleimide by imidization-extrusion of copolymers of styrene and maleic anhydride using a supercritical fluid. The method can be performed at a lower temperature compared to a conventional method and can remove residual amines and by-products with ease, and thus can provide copolymers of styrene and maleimide having excellent optical properties, thermal properties and mechanical properties.
摘要:
The invention relates to a method for producing polymers by dispersion polymerisation. According to said method, the monomer solution contains between 0.01 and 0.2 wt. %, in relation to the monomer, of at least one cross-linking agent. The invention also relates to the use of said polymers for thickening liquids and to a device for producing polymers by dispersion polymerisation.