The Dow Chemical Company

Kent S Dennis

John W Bozzelli

Felipe A Donate

Corwin J Bredeweg

Charles E Lyons

Gene D Rose

Syamalarao Evani

Charles E Reineke

Edwin C Steiner

Joseph W Raksis

Block copolymers are prepared by providing an initial anionically polymerizable monomer portion; anionically polymerizing the initial monomer portion to provide polymer chains with living ends, and contacting the polymer chains with m-bis(phenylethenyl)benzene (PEB), a coupling agent, to bring about substantial coupling. In preferred embodiments the polymer chain living ends are capped with an .alpha.-alkylstyrene or a ring-alkyl substituted .alpha.-alkylstyrene, wherein the .alpha.-alkyl groups contain between about 1 to about 20 carbon atoms, and the ring-alkyl groups have at least 2 carbon atoms. The coupling agents employed with the capped polymer chain living ends include PEB, p-dibromoxylene, terephthaloyl chloride, 1,4-dibromobutene; and the multifunctional epoxides, multifunctional isocyanates, multifunctional aziridines, multifunctional aldehydes, multifunctional ketones, multifunctional anhydrides, multifunctional esters, and polyhalides.

Preparation of triblock copolymers

Block copolymers are prepared by providing an initial anionically polymerizable monomer portion; anionically polymerizing the initial monomer portion to provide polymer chains with living ends, and contacting the polymer chains with m-bis(phenyletheynl)benzene (PEB), a coupling agent, to bring about substantial coupling. In preferred embodiments the polymer chain living ends are capped with an .alpha.-alkylstyrene or a ring-alkyl substituted .alpha.-alkylstyrene, wherein the .alpha.-alkyl groups contain between about 1 to about 20 carbon atoms. and the ring-alkyl groups have at least 2 carbon atoms. The coupling agents employed with the capped polymer chain living ends include PEB, p-dibromoxylene, terephthaloyl chloride, 1,4-dibromobutene; and the multifunctional epoxides, multifunctional isocyanates, multifunctional aziridines, multifunctional aldehydes, multifunctional ketones, multifunctional anhydrides, multifunctional esters, and polyhalides.

An effective method for gelling certain organic liquids. The invention, in one embodiment, comprises forming a solution of the organic liquids and an amount of a triblock copolymer of relatively moderate molecular weight, having poly(4-vinylpyridene) end blocks and a small amount of a salt of a transition metal. In another embodiment, the invention comprises forming a solution of the organic liquids and an amount of a triblock copolymer of relatively moderate molecular weight, having poly(4-vinylpyridene) end blocks and a small amount of an acid. Such gelled liquids are useful as pipe line pigs, in automobile lacquers and in charcoal lighter fluids.

Gelled organic liquid and method for making

The rheology of aqueous liquids is effectively controlled by the addition to the liquid of a water-dispersible BAB triblock polymer wherein the B blocks are hydrophobic blocks such as alkyl or sulfonated poly(t-butylstyrene) and the A block is a hydrophilic block such as sulfonated poly(vinyltoluene).

Triblock polymers of the BAB type having hydrophobic association

1,3-pentadiene is polymerized from a mixture of saturated and unsaturated hydrocarbon compounds, the compounds having primarily 5 carbon atoms per molecule, with an anionic polymerization initiator. The mixture of saturated and unsaturated hydrocarbon compounds is contacted, in an inert atmosphere, with an anionic polymerization initiator to form a reaction mixture. The anionic polymerization initiator is present in an amount sufficient to inactivate polymerization-terminating compounds present in the mixture and to initiate polymerization of 1,3-pentadiene from the mixture. The reaction mixture is heated with stirring to a temperature sufficient to inactivate the polymerization terminating compounds. After inactivation of the polymerization terminating compounds, the reaction mixture is then heated with stirring to a temperature sufficient to initiate polymerization of 1,3-pentadiene from the reaction mixture. Polymer recovery and subsequent functionalization, if any, follow thereafter.

Anionic polymerization of cis- and trans-1,3-pentadiene from a mixture

1,3-Pentadiene is polymerized in an inert gaseous atmosphere from a mixture of saturated and unsaturated hydrocarbon molecules. At least 50 percent by weight of said molecules have 5 carbon atoms. An anionic polymerization initiator in conjunction with an organic polar solvent is used to effect polymerization. Cyclopentadiene, active hydrogen compounds and other polymerization-terminating compounds may be inactivated and separated from the mixture of hydrocarbon compounds before starting polymerization. As an alternative, inactivation and separation of cyclopentadiene, active hydrogen compounds and polymerization-terminating compounds may be omitted provided the anionic polymerization initiator is employed in an amount to (a) inactivate such compounds and (b) initiate polymerization of 1,3-pentadiene. The polymer of 1,3-pentadiene so prepared is then hydrogenated or functionalized by further reaction.

The char-forming characteristics of vinyl aromatic polymers are improved by the incorporation therein of (1) active allyl and/or benzyl carbon moieties and (2) an arylsulfonate ester. In an example, a styrenic polymer comprising polyvinylbenzylacetate is given increased char-forming ability by the presence of pentaerythritol parabromobenzenesulfonate.

Char-forming thermoplastic compositions

The char-forming characteristics of aromatic polymers containing one or more combustion resistant components are improved by incorporating therein a polybenzyl, a polyallyl, or an allyl/benzyl moiety. As an example, a styrene polymer comprising a halogenated comonomer such as bromostyrene is rendered char-forming by the presence of copolymerized vinylbenzyl chloride in the styrene polymer. Such polymeric compositions are useful in the manufacture of shaped articles such as housings for electrical appliances.

Combustion resistant aromatic polymers containing char-forming benzyl

The title compounds are prepared in a process comprising contacting an alkali metal or alkaline earth metal salt of a tetra- or pentahalophenol with a vinylbenzyl chloride in a liquid, aqueous solvent containing from about 68 to about 90 weight percent of a C.sub.1 or C.sub.2 alkanol in a remaining amount of water. The contact of the aforementioned reactants occurs at a pH from about 7 to about 11 and at a temperature less than about 65.degree. C. As an example, sodium pentachlorophenoxide can be reacted with vinylbenzyl chloride by this process in an aqueous methanol solvent (with about 20 weight percent water) to yield about 90 percent pentachlorophenylvinylbenzyl ether, based on vinylbenzyl chloride.

Preparation of halophenylvinylbenzyl ethers

Relatively large amounts of initiator and short reaction times produce high molecular weight copolymers of phenylmaleic anhydride with a monomer such as styrene whereas normally these conditions would be expected to produce low molecular weight copolymers. Additionally, it was found that the molar ratio of phenylmaleic anhydride and comonomers such as styrene should be controlled to about 1:3 to 1:6 to obtain the high molecular weight desired. Limited use of inert solvents is possible.

High molecular weight polymers of phenylmaleic anhydride

An improved resinous structure is disclosed. The structure has a transparent resinous matrix having a light absorbance (optical density) at 640 millimicrons wavelength which is not greater than 0.07 when the structure has a thickness of 10 mils. The continuous matrix polymer is a polymer of about 65 to 95 parts by weight of styrene and 5 to 35 parts by weight of methylmethacrylate. The structure contains a discontinuous phase of a diene rubber in a proportion of about 4 to 12 parts by weight. The rubber is present in the form of particles having an average diameter not exceeding 2 microns, the particles are of a cellular nature and principally of a closed-cell configuration. The cell walls of the particles are not greater than about 0.15 microns in thickness. The rubber particles contain, occluded therein, polymer of a composition generally identical to the matrix polymer. Such resinous bodies are transparent, impact resistant and suitable for many packaging applications.

Transparent impact styrene polymer structure

An improved resinous structure is disclosed. The structure has a transparent resinous matrix of polystyrene, a light absorbance (optical density) at 640 millimicrons wave length which is not more than 0.10 when the structure has a thickness of 10 mils. The structure contains a discontinuous phase of a diene rubber in a proportion of about five to twelve parts by weight per hundred parts by weight of the structure. The rubber is present in the form of particles having an average diameter not exceeding about 2 microns. The particles are of a cellular nature and principally of a closed-cell configuration. The cell walls of the particles are not more than about 0.15 microns in thickness. The rubber particles contain occluded therein a polymer of a composition generally identical to the matrix polymer. Such resinous bodies are transparent, impact resistant, and suitable for many packaging applications.

Transparent impact-resistant polystyrene structure

Monomeric epoxides are purified by mixing with a hydrocarbyl alkali metal. The requisite amount of hydrocarbyl lithium is readily detectable by a change in color of a suitable indicator. The monomeric epoxide so purified can be rapidly and completely polymerized to yield high molecular weight homopolymers or copolymers.

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Midland, MI, United States of America

Kent S Dennis