摘要:
Brominated styrenic polymer is recovered from solution in a vaporizable solvent by converting the solution in a devolatilization extruder into a brominated styrenic polymer melt or flow and a separate vapor phase comprised predominately of vaporizable solvent, recovering the melt or flow from the devolatilization extruder, and allowing or causing the melt or flow to solidify. The solidified brominated styrenic polymer can be subdivided into a powder or pelletized form. Pellets so made have improved hardness and/or crush strength properties along with reduced formation of fines. Brominated anionic styrenic polymer is preferably used in the process.
摘要:
Brominated styrenic polymer is recovered from solution in a vaporizable solvent by converting the solution in a devolatilization extruder into a brominated styrenic polymer melt or flow and a separate vapor phase comprised predominately of vaporizable solvent, recovering the melt or flow from the devolatilization extruder, and allowing or causing the melt or flow to solidify. The solidified brominated styrenic polymer can be subdivided into a powder or pelletized form. Pellets so made have improved hardness and/or crush strength properties along with reduced formation of fines. Brominated anionic styrenic polymer is preferably used in the process.
摘要:
Brominated styrenic polymer is recovered from solution in a vaporizable solvent by converting the solution in a devolatilization extruder into a brominated styrenic polymer melt or flow and a separate vapor phase comprised predominately of vaporizable solvent, recovering the melt or flow from the devolatilization extruder, and allowing or causing the melt or flow to solidify. The solidified brominated styrenic polymer can be subdivided into a powder or pelletized form. Pellets so made have improved hardness and/or crush strength properties along with reduced formation of fines. Brominated anionic styrenic polymer is preferably used in the process.
摘要:
Brominated styrenic polymer is recovered from solution in a vaporizable solvent by converting the solution in a devolatilization extruder into a brominated styrenic polymer melt or flow and a separate vapor phase comprised predominately of vaporizable solvent, recovering the melt or flow from the devolatilization extruder, and allowing or causing the melt or flow to solidify. The solidified brominated styrenic polymer can be subdivided into a powder or pelletized form. Pellets so made have improved hardness and/or crush strength properties along with reduced formation of fines. Brominated anionic styrenic polymer is preferably used in the process.
摘要:
Granules/pastilles of unadulterated brominated anionic styrenic polymer are prepared and provided. They are made by forming a downward plug flow from an orifice in a manifold or nozzle in proximity to a cooled traveling planar member. Such member is impervious to cooling liquid. There is a gap between the lower end of the orifice and the planar member. A portion of a plug of the molten polymer either (i) bridges such gap or (ii) freely drops from the orifice and falls upon the planar member, in either case forming an individual granule/pastille on the planar member and solidifies thereon. The traveling member is cooled by a mist or spray of cooling liquid applied to the underside of the planar member. The granules/pastilles have superior properties.
摘要:
Concurrently fed into a reaction zone held at about 10° C. or less are brominating agent, aluminum halide catalyst, and a solution of anionic styrenic polymer having a GPC Mn about 2000-30,000. The components are in at least two separate feed streams. The feeds are proportioned to maintain (a) the amount of aluminum halide being fed at about 0.8 mole percent or less based on the amount of aromatic monomeric units in the polymer being fed, and (b) amounts of brominating agent and unbrominated polymer in the reaction zone that produce a final washed and dried polymer product containing about 60-71 wt % bromine. The catalyst is deactivated, bromide ions and catalyst residues are washed away from the reaction mixture, and the brominated anionic styrenic polymer is recovered and dried. The dried polymer has a volatile bromobenzene content of about 600 ppm (wt/wt) or less as well as other beneficial properties.
摘要:
Concurrently fed into a reaction zone held at about 10° C. or less are brominating agent, aluminum halide catalyst, and a solution of anionic styrenic polymer having a GPC Mn about 2000-30,000. The components are in at least two separate feed streams. The feeds are proportioned to maintain (a) the amount of aluminum halide being fed at about 0.8 mole percent or less based on the amount of aromatic monomeric units in the polymer being fed, and (b) amounts of brominating agent and unbrominated polymer in the reaction zone that produce a final washed and dried polymer product containing about 60-71 wt % bromine. The catalyst is deactivated, bromide ions and catalyst residues are washed away from the reaction mixture, and the brominated anionic styrenic polymer is recovered and dried. The dried polymer has a volatile bromobenzene content of about 600 ppm (wt/wt) or less as well as other beneficial properties.
摘要:
Preparing brominated styrenic polymer by maintaining a mixture formed from (i) brominating agent, (ii) a solvent solution of styrenic polymer, and (iii) aluminum halide catalyst, at −20 to +20° C., and terminating bromination in 20 minutes or less. New brominated anionic styrenic polymers have better melt flow and/or lower initial ΔE values than the best previously-known brominated anionic styrenic polymers. Other features of such new polymers include high thermal stabilities at 320° C. and/or very low initial color values. Brominated styrenic polymers, especially brominated anionic styrenic polymers, are useful as flame retardants for thermoplastic polymers.
摘要:
Concurrently fed into a reaction zone held at about 10° C. or less are brominating agent, aluminum halide catalyst, and a solution of anionic styrenic polymer having a GPC Mn about 2000-30,000. The components are in at least two separate feed streams. The feeds are proportioned to maintain (a) the amount of aluminum halide being fed at about 0.8 mole percent or less based on the amount of aromatic monomeric units in the polymer being fed, and (b) amounts of brominating agent and unbrominated polymer in the reaction zone that produce a final washed and dried polymer product containing about 60-71 wt % bromine. The catalyst is deactivated, bromide ions and catalyst residues are washed away from the reaction mixture, and the brominated anionic styrenic polymer is recovered and dried. The dried polymer has a volatile bromobenzene content of about 600 ppm (wt/wt) or less as well as other beneficial properties.
摘要:
Preparing brominated styrenic polymer by maintaining a mixture formed from (i) brominating agent, (ii) a solvent solution of styrenic polymer, and (iii) aluminum halide catalyst, at −20 to +20° C., and terminating bromination in 20 minutes or less. New brominated anionic styrenic polymers have better melt flow and/or lower initial ΔE values than the best previously-known brominated anionic styrenic polymers. Other features of such new polymers include high thermal stabilities at 320° C. and/or very low initial color values. Brominated styrenic polymers, especially brominated anionic styrenic polymers, are useful as flame retardants for thermoplastic polymers.