Polymers from intermediates obtained from hydrogen cyanide

The recent demonstration of an easy synthesis of diiminosuccinonitrile (DISN) from hydrogen cyanide and cyanogen, the reduction of DISN to diaminomaleonitrile (DAMN), and the use of these compounds to form difunctional heterocycles has made several new polyamide intermediates accessible. The 1- and 2-methyl-1,2,3-triazole-4,5-dicarbonyl chlorides have been polymerized interfacially to form high-melting polyamides of good heat stability. Interfacial polymerization of 1-methylimidazole-4,5-dicarbonyl chloride and trans-2,5-dimethylpiperazine has given a polyamide that is water-soluble. The 2,6- and 2,3-pyrazinedicarbonyl chlorides have been similarly converted to high-melting polyamides. 2,6-Dicyano-3,5-dipiperazinylpyrazine has been prepared from tetracyanopyrazine and piperazine and reacted with toluene diisocyanate to form a strong, stiff polyurea. Polyamides were also made from 2,3-diaminoquinoxaline, 1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile, and DAMN.     

Microwave step‐growth polymerization of 5‐(4‐methyl‐2‐phthalimidylpentanoylamino)isophthalic acid with different diisocyanates

The utilization of microwave energy in polymer synthesis is a fast growing field of research leading to a more rapid and cleaner polymerization process. In order to synthesize novel optically active monomer 5‐(4‐methyl‐2‐phthalimidylpentanoylamino)isophthalic acid ( 6 ), the reaction of phthalic anhydride with l ‐leucine was carried out in an acetic acid solution and 4‐methyl‐2‐phthalimidylpentanoic acid as an imide acid was obtained in good yield. Then, it was converted to 4‐methyl‐2‐phthalimidylpentanoyl chloride by treatment with thionyl chloride. This acid chloride was reacted with 5‐aminoisophthalic acid and the novel bulky aromatic amide‐imide chiral monomer 6 was obtained in high yield and was characterized with spectroscopy techniques as well as specific rotation and elemental analysis. Polycondensation of monomer 6 with different diisocyanates such as 4,4′‐methylenebis(phenyl isocyanate), toluene‐2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate was performed by two different methods: microwave irradiation and classical heating polymerization techniques in the presence of various catalysts and without a catalyst. The microwave polymerization technique provides a new way for the production of polymers at high rates. The resulting novel optically active polyamides have inherent viscosities in the range of 0.25–0.63 dl/g. They show good thermal stability and are soluble in amide‐type solvents. The obtained polyamides were characterized by FT‐IR, ¹H‐NMR spectroscopy, elemental analyses, specific rotation, and thermal analyses methods. Copyright © 2008 John Wiley & Sons, Ltd.     

A facile, microwave-assisted synthesis of novel optically active polyamides derived from 5-(3-methyl-2-phthalimidylpentanoylamino)isophthalic acid and different diisocyanates

5-(3-Methyl-2-phthalimidylpentanoylamino)isophthalic acid as a novel aromatic diacid monomer was prepared in three steps. In the first step, phthalic anhydride was reacted with l-isoleucine in acetic acid solution, and the resulting imide acid was obtained in high yield. In the second step, treatment of this imide acid with excess thionyl chloride gave aliphatic acid chloride in good yield. In the last step, this acid chloride was reacted with 5-aminoisophthalic acid to provide novel bulky chiral aromatic diacid monomer. The direct polycondensation reactions of this diacid with several aromatic and aliphatic diisocyanates such as 4,4′-methylenebis(phenyl isocyanate), toluylene-2,4-diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate were carried out under microwave irradiation. In order to compare this method with classical heating, the polymerization reactions were also performed under solution polycondensation conditions. The polymerization reactions occurred rapidly under microwave conditions and produced a series of novel optically active polyamides (PA)s containing pendent phthalimide group, with good yields and moderate inherent viscosities of 0.17-0.60 dL/g. Some of the new PAs showed good solubility and are readily soluble in organic solvents. The resulting macromolecules were characterized by FT-IR, specific rotation, and representative ones by ¹H NMR, elemental and thermogravimetric analyses (TGA).     

Regioselective synthesis of (±)-gabaculine hydrochloride

3- Cyclohexenecarboxylic acid (2) has been functionalized to the protected amino acid 5 in a novel reaction sequence, the crucial step being the acid catalysed cyclization of the γ, δ-unsaturated isocyanate 3 to the bicyclic lactam 4. 5 was converted into gabaculine hydrochloride (1 · HCl).     

单组分阴离子聚氨酯水乳液结构与性能

聚氨酯乳液;聚醚多元醇;二羟甲基丙酸;单组分阴离子聚氨酯水乳液结构与性能     

Preparation and properties of aromatic copolyamides from aromatic diisocyanates and aromatic dicarboxylic acids

Wholly aromatic random copolyamides of high molecular weights were prepared by the high-temperature solution polycondensation of an aromatic diisocyanate, 4,4′-methylenedi(phenyl isocyanate) or 2,4-tolylene diisocyanate, with a mixture of isophthalic acid and 4,4′-oxydibenzoic acid. Glass transition temperatures of the polyamides and copolyamides were between 229 and 273°C; this depended on the combination of diisocyanates and dicarboxylic acids used. These aromatic copolyamides showed better solubility in various organic solvents and reduced crystallinity, compared to the corresponding homopolyamides. The copolyamides prepared from 2,4-tolylene diisocyanate had greater solubility and higher glass transition temperatures than those obtained from 4,4′-methylenedi(phenyl isocyanate).     

Synthesis and radical polymerization of end-methacrylated poly(succinimide) leading to poly(aspartic acid) hydrogel

The polycondensation of aspartic acid in the presence of phthalic anhydride was carried out in mesitylene/sulfolane using o-phosphoric acid as a catalyst. The polymer yields were 91–78%, when 5–20 mol-% phthalic anhydride was added into the feed. The obtained poly(succinimide) carried a phthalic imide unit and a succinic acid unit as end groups. In the MALDI-TOF mass spectrum, the peak-to-peak distances between adjacent signals were 97.07 m/z, corresponding to the calculated value (97.07) of the succinimide unit. Poly(succinimide) was reacted with 2-(methacryloxy)ethyl isocyanate to give end-methacrylated poly-(succinimide), in which the end-functionality of the methacrylate group was ca. 1. End-methacrylated poly-(succinimide) was polymerized with ethylene glycol dimethacrylate using 2,2′-azoisobutyronitrile to give poly(succinimide) gel, which could be converted into water-absorbing poly(aspartic acid) hydrogel.     

Polymers containing 12-hydroxymethyltetrahydroabietanol

12-Hydroxymethyltetrahydroabietanol has been polymerized with hexamethylene diisocyanate and a low molecular weight polyurethane produced. Low molecular weight polyurethanes have also been prepared from 12-hydroxymethyltetrahydroabietyl chloroformate, hexamethylenediamine, and sym.-dimethylethylenediamine. 12-Hydroxymethyltetrahydroabietanol has been “end-capped” with tolylene-2,4-diisocyanate and hexamethylene diisocyanate. The resulting diisocyanates have been polymerized with polytetramethylene glycol, hexamethylenediamine and hydrazine.     

Polyesters,polyurethanes and epoxy resins derived from 2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyquinaldine and 6-(4-hydroxystyryl)-3-hydroxypyridine

New polyesters and polyurethanes as well as diepoxides bearing styrylpyridine segments were prepared utilizing 2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyquinaldine (PBHQ) and 6-(4-hydroxystyryl)-3-hydroxypyridine (HSHP) as starting materials. The polyesters were prepared by reacting PBHQ or HSHP with terephthaloyl dichloride in the presence of an acid acceptor utilizing the solution polycondensation method. The polyurethanes were prepared from the reactions of PBHQ and HSHP with tolylene diisocyanate and methylenebis(4-phenylisocyanate). In addition, model diesters and diurethanes were synthesized by reacting PBHQ and HSHP with benzoyl chloride and phenyl isocyanate, respectively. Model compounds and polymers were characterized by FT-IR and ¹H-NMR spectroscopy as well as by DTA and TGA. Diepoxides were also prepared from the reactions of PBHQ and HSHP with epichlorohydrin which were polymerized in the presence of 4,4′-diaminodiphenylsulfone. The polyesters were the most thermostable polymers obtained. After curing at 240°C for 20 h, they were stable in N₂ up to 345–370°C and afforded anaerobic char yields of 65–75% at 800°C. © 1993 John Wiley & Sons, Inc.     

1-(Aziridine) carbonyl chlorides and 1-(aziridine) carbonyl quaternary ammonium chlorides. Rearrangement to 2-(chloroalkyl) isocyanates

Aziridine reacted with phosgene in the presence of an acid acceptor or with 1,1′-carbonylbis(pyridinium) chloride to produce 1-(aziridine)carbonyl chloride (XII) or 1-(aziridine)carbonyl pyridinium chloride (XIII), respectively, as transient intermediates. Attempts to trap and observe (XII) and (XIII) at -10° were unsuccessful. These elusive materials underwent facile rearrangements to 2 - chloroethyl isocyanate under these conditions. Aziridine reacted with 1,1′-carbonylbis(triethylammonium)chloride (VII) at -20° to give 1-(aziridine) carbonyl triethylammonium chloride (X) as a transient intermediate which proceeded to 2-chloroethyl isocyanate. At -10° this reaction produced N,N-diethyl-1-aziridinecarboxamide. Aziridine reacted with a large excess of phosgene in the absence of an acid acceptor to give N-2-(chloroethyl) carbamoyl chloride (III), 1,1′-bis(2-chloroethyl) urea (IV) and 2-(β-chloroethylamino)-2-oxazoline hydrochloride (V). Possible mechanisms for these reactions are discussed.     

Polyesters,polyurethanes, and epoxy resin derived from 2,2′-(1,4-phenylenedivinylene)bis-5-hydroxypyridine

2,2′-(1,4-Phenylenedivinylene)bis-5-hydroxypyridine (PBHP) was used as a starting material for preparing new polyesters and polyurethanes as well as a diepoxide-bearing styrylpyridine segments. The diesters were prepared by reacting PBHP with terephthaloyl or adipoyl dichloride utilizing the interfacial polycondensation method. The diesters were prepared from the reaction of PBHP with tolylene diisocyanate or methylenebis(4-phenylisocyanate). In addition, a model diester and diurethane were synthesized by reacting PBHP with benzoyl chloride and phenyl isocyanate, respectively. Both model compounds and polymers were characterized by IR and ¹H-NMR spectroscopy, as well as by DTA and TGA. A diepoxide was also prepared from the reaction of PBHP with epichlorohydrin which was polymerized in the presence of 4,4′-diaminodiphenylsulfone. The polyester derived from PBHP and terephthaloyl dichloride was the most thermostable polymer obtained. It was stable in N₂ up to 355°C and afforded an anaerobic char yield of 59% at 800°C. The thermal stabilities of polymers were improved by curing.     

Polyurethanes and polyureas having long methylene chain units

Polyurethanes and polyureas containing long methylene chain units have been prepared from the following six series of monomer combinations; aliphatic diisocyanates with aliphatic glycols or diamines, methylene bis(4-phenyl isocyanate) with aliphatic glycols or diamines, and p-xylylene diisocyanate with aliphatic glycols or diamines. A good linear relationship was noted between the polymer melting points of each series against the concentration of functional groups. Both polyurethanes and polyureas from p-xylylene diisocyanate showed higher melting points than those from methylene bis(4-phenyl isocyanate) with corresponding aliphatic monomers. The relations between the melting points of these polymers with long methylene chains, including polyamides which were previously reported, and the chain components were discussed. The higher melting points of polymers containing p-xylylene group are attributed to the high rigidity of this group.     

Polytetrazoles and polyaminotetrazoles

Polyaminotetrazoles were obtained by the action of hydrazoic acid on solutions of polycarbodimides prepared from methylenebis(4-phenyl isocyanate), toluene 2,4-diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, mesitylene diisocyanate, and hexamethylene diisocyanate. The polyaminotetrazoles, which were soluble only in concentrated sulfuric acid, had inherent viscosities of 0.12–0.78. Polymerization of the disodium salts of bistetrazoles with α,ω-dihalides gave polytetrazoles without the secondary amine linkage in the chain. The bistetrazoles, used were methylenebis(5-tetrazole) and 5,5′-p-phenylenebistetrazole, and the dihalides were α,α′-dichloro-p-xylene, 1,2-dibromoethane, and 1,4-dibromobutane. The polytetrazoles were soluble in concentrated sulfuric acid and had low inherent viscosities, 0.08–0.17. Thermogravimetric analyses showed that marked degradation of both classes of polymers occured at 250–300°C.     

Self-regulating polycondensations. IV. Ordered oxadiazole-imide copolymers

Ordered oxadiazole-imide copolymers are prepared from simple aminobenzhydrazide monomers by a step-wise reaction which begins with the condensation of a diacid chloride to produce in situ a diamine containing hydrazide linkages. The in situ diamine is then reacted with a dianhydride to yield an ordered hydrazide-amic-acid copolymer; this precursor is converted by heating to the ordered heterocycle copolymer. Polymers prepared via this manner are identical in properties to those obtained by the reaction of a dianhydride with a diamine containing hydrazide linkages preformed by a straight forward synthesis from a dinitro precursor. Fibers spun from the soluble precursor polymers were converted via cyclodehydration to thermally stable fibers. Another polyoxadiazole-imide was produced in similar fashion; e.g., an aminobenzhydrazide was reacted with the acid chloride of trimellitic anhydride to yield an in situ AB monomer which was polymerized to yield a precursor polyhydrazide-amic-acid, which in turn was converted by cyclodehydration to an AB type polyoxadiazole-imide. Additional examples are cited of the formation of polymers from the in situ intermediates produced by the “self-regulating” reaction of aminobenzhydrazides with acid chlorides followed by polycondensation with difunctional monomers.     

Synthesis and Reactions of N-Chlorocarbonyl Isocyanate

Cl? CO? N?C?O (N-chlorocarbonyl isocyanate) is prepared in 90% yield by partial hydrolysis of the addition product of phosgene and cyanogen chloride. Many derivatives of the iminocarboxylic acid parent compound can be obtained from this highly reactive species. Both the acid chloride and the isocyanate group are amenable to reactions exhibiting overall selctivity, and this opens the way, inter alia, to a simple preparative synthesis of isocyanates from alcohols, phenols, thiols, and thiophenols. Combination of the two functional groups and their peculiar symmetry, which becomes evident, e.g. in the HCl adduct, facilitates ready cyclization of N-chlorocarbonyl isocyanate under very mild conditons.     

Dipyrrolo[1,2-a:2',1'-c]pyrazines. 8. Electrophilic Substitution in Dipyrrolo[1,2-a:2',1'-c]pyrazines and 5,6-Dihydrodipyrrolo[1,2-a:2',1'-c]pyrazines. Acylation of Dipyrrolo[1,2-a:2',1'-c]pyrazines

Esters, nitriles, and amides of dipyrrolo[1,2-a:2',1'-c]pyrazines have been synthesized by the acylation of dipyrrolo[1,2-a:2',1'-c]pyrazines and 5,6-dihydrodipyrrolo[1,2-a:2',1'-c]pyrazines with trichloroacetic acid chloride, p-tosyl isocyanate, and isocyanatophosphoric acid dichloride (Kirsanov isocyanate).     

Preparation and properties of aromatic–aliphatic copolyamides from aromatic diisocyanates and dicarboxylic acids

Aromatic–aliphatic random copolyamides of high molecular weights were prepared by the high-temperature solution polycondensation from a combination of aromatic diisocyanates, 4,4′-methylenedi(phenyl isocyanate), and 2,4-tolylene diisocyanate, and a mixture of isophthalic acid and aliphatic dicarboxylic acids with 4–10 methylene groups. Reaction conditions, such as solvent, temperature, time, and catalyst were studied to determine the optimum conditions for the preparation of high molecular weight polymers. Glass transition temperatures of the copolyamides were in the range of 131–244°C and varied with combination and composition of the diisocyanates and dicarboxylic acids used. The copolyamides prepared from 2,4-tolylene diisocyanate had greater solubility and higher glass transition temperatures than those obtained from 4,4′-methylenedi(phenyl isocyanate).     

Synthesis and properties of multiblock copolymers based on polydimethylsiloxane and polyamides from dicarboxylic acid and diisocyanate terminated functionalities

Polydimethylsiloxane (PDMS)–polyamide multiblock copolymers were successfully synthesized via diisocyanate route by two different procedures, i.e., the one-step and two-step methods, In the two-step method, α, ω-diisocyanate-terminated polyamide oligomers, which were prepared in situ from a mixture of isophthalic acid (IPA) and azelaic acid (AZA) with 4,4′-methylenedi (phenyl isocyanate) (MDI) in 1,3-dimethyl-2-imidazolidone (DMI) in the presence of 3-methyl-1-phenyl-2-phosopholene 1-oxide catalyst, were reacted with α, ω-bis (10-carboxydecyl) polydimethylsiloxane (PDMS-diacid) leading to the formation of multiblock copolymers. In the one-step method, the reaction components, MDI, IPA, AZA, and PDMS-diacid were reacted all together in DMI in the presence of the catalyst. These polymerizations gave multiblock copolymers having inherent viscosities in the range of 0.36–1.12 dL/g in N,N-dimethylacetamide (DMAc). These multiblock copolymers were soluble in amide-type solvents, and transparent (or translucent) and ductile films could be cast from the solutions in a mixture of DMAc and bis(2-ethoxyethyl) ether. The multiblock copolymers prepared by the two-step method had better-defined, microphase-separated morphology than those obtained by the one-step method. The mechanical properties of PDMS–polyamide multiblock copolymer films were found to be highly dependent on the PDMS content; the tensile strength and modulus of the films decreased with increasing the PDMS content.     

Synthesis and characterization of polyurethane–polyvinylbenzyl chloride multiblock copolymers and their cationomers using a polyurethane macroiniferter

Polyurethane iniferter prepared from isocyanate end capped prepolymer and 1,1,2,2-tetraphenyl-1,2-ethanediol, has been used to polymerize vinylbenzyl chloride to obtain polyurethane-polyvinylbenzyl chloride multiblock copolymers. Formation of the block copolymers proceeds with increase in both molecular weight and conversion with increasing polymerization time showing that the polymerization proceeds via a “living” radical mechanism. The block copolymers so obtained were converted into their cationomers by the treatment of triethylamine. The block copolymers and their cationomers have been characterized by FTIR, FTNMR, TGA, and DSC studies. The effect of thermal energy on the molecular weight of the macroiniferter in the absence of monomer has been studied in order to understand the mechanism of formation of the block copolymers. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1237–1244, 1997     

Preparation of polyhydrouracils and polyiminoimidazolidinones

Polyhydrouracils and polyiminoimidazolidinones were prepared by ring formation along the chain of appropriately substituted polyureas. Cyclization of 2-carbomethoxy-ethyl-substituted polyureas in a polyphosphoric acid medium gave the polyhydrouracils. The polyurea precursors were prepared from N,N′-bis(2-carbomethoxyethyl)-1,6-hexanediamine and N,N′-di(2-carbomethoxyethyl)-1,4-cyclohexanebis(methylamine) with methylenebis(4-phenyl isocyanate), 2,4-toluene diisocyanate, and 3,3′-dimethoxy-4,4′-biphenylene diisocyanate. These polyureas were soluble in m-cresol, dimethylformamide, and chloroform, had inherent viscosities of up to 0.8, and could be cast into tough films. The polyhydrouracils had similar physical properties and could also be cast into films. The polyhydrouracils melted at temperatures 100–150°C higher than their polyurea precursors. Polyiminoimidazolidinones were prepared by cyclization of α-cyanoalkyl-substituted polyureas in the presence of n-butylamine. The intermediate polyureas, which were not isolated, were prepared from methylenebis(4-phenyl isocyanate) with N,N′-bis(1-cyanocyclohexyl)-1,6-hexanediamine, N,N′-bis(1-cyanocyclohexyl)-m-xylylenediamine and N,N′-bis(1-cyanocyclopentyl)-1,6-hexanediamine. The polyiminoimidazolidinones were soluble in m-cresol, dimethylformamide, and chloroform and had low inherent viscosities of 0.14–0.28. Thermogravimetric analyses showed that the polyhydrouracils underwent rapid decomposition at 400°C, whereas an analogous unsubstituted polyurea decomposed at 300°C. On the other hand, the polyiminoimid-azolidinones showed no greater thermal stability than the unsubstituted polyurea.