Ethyl Corporation

Hsueh M Li

Edwin D Hornbaker

Jesse D Jones

James Y Chung

F Alexander Pettigrew

Burnell Lee

Genevieve S Lum

John Y Lee

Dixie E Goins

Fusible polyimide powders are prepared by the process of this invention. An amic acid amine is first prepared by treating (n+1) moles of a bis(aminophenyl)methane with n mole of aromatic tetracarboxylic anhdride to produce an aromatic amic acid prepolymer. This prepolymer is then mixed with an unsaturated carbocyclic monoanhydride and the mixture heated to form a reactive end-capped polyamic acid precursor. The resulting composition is thermally treated in order to partially imidize the precursor. The resulting fusible polyimide powder is finally separated.

Production of particulate amide/imide prepolymers

Novel substituted phosphazene compounds are disclosed having the formula ##STR1## wherein w, x, y and z are integers the sum of which is from 3 to 6 with the proviso that w is at least 1 but equal to or less than (w+x+y+z)-1, x is from 1 to 5, y and z are from 0 to 2;

Phosphazene antioxidants

This invention discloses a process where a portion of an amine terminated polyamic acid intermediate is end-capped with an aromatic monoanhydride additionally substituted with a free carboxylic acid and a carboxylic ester. The polyamic acids of this invention are readily converted to high molecular weight polyimides.

Process for forming end capped polyamic acids polyimides

This invention discloses a process where a portion of an amine terminated polyamic acid intermediate is end-capped with an aromatic monoanhydride additionally substituted with a free carboxylic acid or ester thereof. The polyamic acids of this invention are readily converted to high molecular weight polyimides which may contain a small amount of amide groups.

Process for forming end-capped polyamic acids polyimides

Halophosphazene polymers such as linear phosphonitrilic chloride polymers are prepared in two stages by (i) heating a nitrogen source (e.g., NH.sub.3 ; NH.sub.4 Cl; etc.) with an excess of a phosphorus source (e.g., PCl.sub.5 ; PCl.sub.3 +Cl.sub.2 ; P+Cl.sub.2 ; etc.) so that hydrogen halide is evolved and halophosphazene is formed, and (ii) heating at least a portion of the halophosphazene with at least a stoichiometric amount (preferably an excess) of a nitrogen source (e.g., NH.sub.3 ; NH.sub.4 Cl; etc.) so that hydrogen halide is evolved and halophosphazene polymer of higher molecular weight is formed. Preferably, a third stage is utilized wherein the resultant halophosphazene polymer is then heated, most preferably in an inert solvent or diluent which enhances the fluidity of the reaction mixture, to increase the molecular weight of the polymer.

Phosphonitrilic halide polymers

Improved injection moldability of polyethylene terephthalates is achieved by the addition of an epoxidized plasticizer and a nucleating agent cooperative with the epoxidized plasticizer to achieve the improved moldability even when the composition is injection molded using mold temperatures of at least as low as 93.degree. C.

Injection-moldable thermoplastic polyester composition

To prepare halophosphazene oligomer enriched in cyclic trimer, a two-stage process is used. In the first stage halogen halide and ammonia are concurrently introduced into an agitated liquid reaction medium in which halophosphazene oligomer is soluble, these materials being proportioned so as to form a reaction system composed of a dilute slurry of finely divided ammonium halide particles. In the second stage phosphorus trihalide and halogen are concurrently introduced into the slurried reaction system from the first stage heated to a temperature of about 80.degree. to about 180.degree. C. In the process the quantities of the reactants introduced into the reaction medium are proportioned such that the ammonium halide:phosphorus trihalide molar ratio is between about 1:1 and about 3:1, and the phosphorus trihalide:halogen molar ratio is kept above about 0.5:1 and below about 2:1 until all of the phosphorus trihalide has been introduced, and thereafter the halogen is introduced in an amount sufficient to give a total phosphorus trihalide:halogen molar ratio above about 0.5:1 but below about 1:1.

Selective oligomer production

One or a mixture of compounds of the formula:

Halophosphazene polymers

Linear phosphonitrilic chloride polymers are produced from phosphonitrilic chloride oligomers by means of a two-stage process. In the first stage a mixture of phosphonitrilic chloride oligomers enriched in linear oligomer is heated with at least a stoichiometric amount (and preferably an excess) of ammonia or ammonium chloride while concurrently removing hydrogen chloride to produce an intermediate reaction product. In the second stage the molecular weight of the reaction product is increased by heating the product to a higher temperature than the average temperature used in the first stage. Cyclic phosphonitrilic chloride oligomer may be present in the initial oligomer. Preferably, cyclic phosphonitrilic chloride oligomer is recovered from the reaction mixture after the start of the second stage. Most preferably it is recovered after completion of the second stage. At least a portion of the recovered cyclic oligomer may be used in a subsequent first stage reaction.

Phosphonitrilic chloride polymers

Linear phosphonitrilic chloride polymers are produced from phosphonitrilic chloride oligomers by means of an improved process wherein a mixture of phosphonitrilic chloride oligomers enriched in linear oligomer is heated with at least a stoichiometric amount (and preferably an excess) of ammonia or ammonium chloride while concurrently removing hydrogen chloride to produce a higher molecular weight polyphosphonitrilic chloride product. Cyclic phosphonitrilic chloride oligomer may be and preferably is present in the initial oligomer. Preferably, cyclic phosphonitrilic chloride oligomer is recovered from the reaction mixture during (but more preferably after) completion of the polymerization reaction. At least a portion of the recovered cyclic oligomer may be used in a subsequent polymerization reaction.

Linear phosphonitrile chloride polymers are produced from linear phosphonitrilic chloride oligomers by means of a two-step proess. In the first step a mixture of linear phosphonitrilic chloride oligomer having an average degree of polymerization of at least 3 and preferably at least 4 is heated with an excess of ammonia or ammonium chloride having a relatively small particle size such that the Mean Value is within the range of from about 1 micron to about 110 microns. Cyclic phosphonitrilic chloride oligomer formed during the course of the first step is removed from the reaction mixture. After the removal of the cyclic oligomer the reaction mixture is subjected to the second step which involves heating the mixture in an inert liquid solvent (optionally in the presence of ammonia or ammonium chloride having a relatively small particle size) whereby the molecular weight of the linear phosphonitrilic chloride polymer is increased.

Linear phosphonitrilic chloride polymers are produced from linear phosphonitrilic chloride oligomers by means of a two-step process. In the first step a mixture of linear phosphonitrilic chloride oligomer having an average degree of polymerization of at least 4 is heated with an excess of ammonia or ammonium chloride. Cyclic phosphonitrilic chloride oligomer formed during the course of the first step is removed from the reaction mixture. After the removal of the cyclic oligomer the reaction mixture is subjected to the second step which involves heating the mixture in an inert liquid solvent (optionally in the presence of ammonia or ammonium chloride) whereby the molecular weight of the linear phosphonitrilic chloride polymer is increased.

Liquid, linear, crosslinkable phosphazene compositions and a process for their preparation are disclosed. These liquid compositions, prepared from normally solid polyphosphazene, contain the polyphosphazene in admixture with from about 1 to about 30 parts per hundred parts of polymer of a polythiol, a polyacrylate, a polymethacrylate or mixtures thereof such that the combination has a viscosity of less than 500,000 cps at 23.degree. C. These compositions are easily handled and can be crosslinked at ambient temperatures.

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Baton Rouge, LA, United States of America

Hsueh M Li