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:
A brominated styrenic polymer reaction mixture containing at least (i) brominated styrenic polymer, (ii) bromination reaction solvent, (iii) hydrogen bromide, and (iv) Lewis acid bromination catalyst, and an aqueous medium in an amount sufficient to deactivate the Lewis acid catalyst but insufficient to form a separate continuous liquid phase in the resultant mixture are mixed together to terminate bromination. The advantages of using such small amounts of aqueous medium, as well as various follow on procedures are described.
摘要:
Bromination of styrenic polymer is carried out in a closed reaction system to retain HX coproduct (where HX is HBr or HCl, or both) in the bromination reaction mixture at superatmospheric pressure. Preferably, the reaction mixture which includes the brominated styrenic polymer and substantially all of the HX coproduct formed is discharged into an aqueous quenching medium. By operating in this manner, the reaction is terminated and the brominated styrenic polymer of desired bromine content and substantially all HX coproduct are captured in the same operation, process equipment costs are reduced, and processing of the reaction mixture is facilitated.
摘要:
A polymeric sorbent that can be employed in the extraction and purification of polar and nonpolar molecules from a complex media (e.g. pharmaceuticals from biological matrices) by solid phase extraction (SPE). The sorbent exhibits a strong capacity for the retention of polar molecules and can facilitate the recovery of compounds possessing a range of polarities while furnishing clean extracts showing low ion suppression. The polymer is wettable and remains wetted over long periods of time.
摘要:
A polymeric sorbent that can be employed in the extraction and purification of polar and nonpolar molecules from a complex media (e.g. pharmaceuticals from biological matrices) by solid phase extraction (SPE). The sorbent exhibits a strong capacity for the retention of polar molecules and can facilitate the recovery of compounds possessing a range of polarities while furnishing clean extracts showing low ion suppression. The polymer is wettable and remains wetted over long periods of time.
摘要:
A vinyl ester resin is derived from the reaction of an unsaturated acid with an epoxy terminated polymer made from a dithio or a trithio initiator, and optionally from an epoxy resin. The vinyl ester resin can be blended with a miscible toughener and a diluent to provide a time stable system and subsequently crosslink to provide a composition with improved toughening properties.
摘要:
A polymeric sorbent that can be employed in the extraction and purification of polar and nonpolar molecules from a complex media (e.g. pharmaceuticals from biological matrices) by solid phase extraction (SPE). The sorbent exhibits a strong capacity for the retention of polar molecules and can facilitate the recovery of compounds possessing a range of polarities while furnishing clean extracts showing low ion suppression. The polymer is wettable and remains wetted over long periods of time.
摘要:
The present invention provides urethane oligomers of null,functional heterotelechelic polymers, and in particular heterotelechelic polyolefins having at least one terminal hydroxyl functionality and one other terminal functional group which is different from the hydroxyl functionality, such as an amine functional group. The oligomers of the invention can exhibit toughness, chemical resistance and other desired properties. The oligomers can also exhibit improved flexibility and impact resistance, due to the incorporation of the polyolefinic backbone. Thus the oligomers can be used in a variety of applications, including without limitation coatings, sealants, adhesives, and composites (prepregs). The heterotelechelic polyolefin is advantageously prepared via anionic polymerization using lithium initiators, and in particular functionalized lithium initiators having a protected hydroxy functionality as known in the art. The resulting living chain end can be functionalized using an amine functionalized electrophile, in which typically the amine group is protected. Alternatively amine protected functionalized initiators can used and the resulting living polymer functionalized using a hydroxy functionalizing electrophile. Protecting groups, when present, are removed to liberate the desired functionalities.
摘要:
Compositions including one or more anionic polymerization initiators and one or more additives for improving functionalizing efficiency of living polymer anions are disclosed. The present invention also provides compositions including one or more electrophiles and one or more additives for improving functionalizing efficiency of living polymer anions. Novel electrophiles and processes for improving polymer anion functionalization efficiencies are also disclosed.
摘要:
A hydrogenated product of an aromatic vinyl polymer, wherein the hydrogenation rate of the aromatic rings thereof is at least 97%, a ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is at most 2.0, the weight average molecular weight (Mw) is 100,000 to 300,000, and the content of a component having a molecular weight (M) of at most 10,000 is at most 2% by weight based on the total weight of the polymer; a hydrogenated product of an aromatic vinyl polymer, wherein the content of foreign matter having a particle diameter of at least 0.5 &mgr;m in the hydrogenated polymer is at most 3.0×104 particles/g; and a substrate for information recording media obtained by molding a resin material containing a hydrogenated product of an aromatic vinyl polymer, wherein the hydrogenation rate of the aromatic rings thereof is at least 97%, a :ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is at most 2.0, and the weight average molecular weight (Mw) is 100,000 to 300,000, and production process thereof.