Benzophenone-3,3 ,4,4 -tetracarboxylic acid

As can be seen from Table 3.1, polyimides based on 4,4 -diaminobenzophenone and common dianhydrides of tetracarboxylic acids (those of pyromellitic, diphenyloxide-3,3, 4,4 -tetracarboxyhc and benzophenone-3,3, 4,4 -tetracarboxylic acids) possess good thermal properties. However, when in their cyclised forms they are practically insoluble in organic solvents, which restricts the possibility of their investigation, processing and use. 

To improve the solubility of polyimides, Korshak and co-workers used l,l-dichloro-2,2-bis(4-aminophenyl)-ethylene as the starting nucleophile [17] (Scheme 3.2). The resulting polymers turned out to be of relatively high molecular weight (r = 1.2-1.4 dl/g), heat resistant > 270 °C) and fire resistant (oxygen index (OI) = 36-39) (Table 3.2). Polypyromellitimide was soluble in H2SO4 only, but polyimides based on the dianhydrides of benzophenone-3,3, 4,4 -tetracarboxylic acid and diphenyloxide-3,3, 4,4 -tetracarboxylic acid were also soluble in w-cresol and a trichloroethane (TCE)/phenol (3 1) mixture. Diphenyloxide-3,3, 4,4 -tetracarboxylic acid was soluble even in N-methyl-2-pyrrolidone (NMP) (Scheme 3.2). 

Imidisation of PCA based on 4,4 -di-(/7-aminophenoxy)-benzophenone was accompanied by the precipitation of the polymers from the reaction solutions, which is partially due to crystallinity in the polyimides formed. This appears to hinder the solubility of the polymers in amide and phenolic solvents. Polyimides based on l,l-dichloro-2,2-di-(/7-aminophenoxyphenyl)-ethylene are more soluble. The polymer formed from this diamine and the dianhydride of benzophenone-3,3 -4,4 -tetracarboxylic acid is soluble in a TCE/phenol (3 1) mixture. 

Polyimides based on l-amino-3-phenoxy-5-(4-aminophenoxy)-benzene and snch dianhydrides as dianhydride of diphenyloxide-3,3 4,4 -tetracarboxylic acid, dianhydride A and dianhydride 6F are soluble in NMP, dimethylformamide (DMF), w-cresol, THF and chloroform. The polyimide based on benzophenone-3,3, 4,4 -tetracarboxylic acid dianhydride is partially soluble in w-cresol and NMP it is insoluble in chloroform, THF and DMF. Polypyromellitimide is insoluble in all the solvents tested. 

Polyimides based on 3,5-diaminodiphenylsulfide demonstrate that solubility in organic solvents strongly depends on the nature of the dianhydride used polymers based on dianhydride 6F and dianhydride A are soluble in NMP, chloroform and acetone polyimides based on diphenyloxide-3,3, 4,4 -tetracarboxylic and benzophenone-3,3, 4,4 -tetracarboxylic acid dianhydrides are soluble in NMP only. Polyimides demonstrate high aired NMP (0.79-1.20 dl/g) and moderate (210-250 °C) Tg values combined with high (400-460 °C) T egr-... 

A number of benzophenones (Ar COAr , where Ar = Ar = p-OaN-CeHa, At = Ar = CjFs, or Ar = CoFb, Ar = CeHg) have been converted into the corresponding difluorodiphenylmethanes (Ar CFjAr ) by treatment with sulphur tetrafluoride benzophenone-3,3, 4,4 -tetracarboxylic acid dianhydride yields the tetrakis(acyl fluoride) (10) under similar conditions. The action of sulphur tetrafluoride on mellitic acid, CtfCOaH), yields... 

Polyimides derived from 3,3, 4,4 -benzophenone tetracarboxylic acid dianhydride (BTDA), I, and 3,3 -diaminobenzophenone (m,m -DABP), IIA, 4,4 -diaminobenzophenone (p,p -DABP), IIB, or 4,4 -oxydianiline, IIC, (and to which have been added numerous metal compounds) have been prepared. The synthetic procedure em-... 

Fully imidized soluble polyimides have ben prepared using monomers derived from diphenylindane and aromatic dianhydrides. Technical polymers (XU218, for instance), prepared from 1,1,3-trimethyl-diaminophenylindane and benzophenone-tetracarboxylic acid dianhydride, have been marketed over the last decade. Despite the partially aliphatic nature of polyimides containing the indane group, they show considerable retention of the thermal stability, with Tg values over 300 °C [107-110]. 

Wheeler, I. (1979). Copper phthalocyanine pigment production— by reacting compound forming phthalocyanine ring system, benzophenone-tetracarboxylic acid, copper compound, catalyst and nitrogen source. Ciba-Geigy Patent GB 1 544 171. [266, 267]... 

IR spectroscopy may be used to follow two reactions occurring in polyimides exposed to high temperatures and humidities hydrolysis of the imide linkages and hydrolysis of residual anhydride end groups. The hydrolytic susceptibilities of several polyimides were measured at 90°C/95% R.H. Polymers based on benzophenone tetracarboxylic acid dianhydride (with either oxydianiline or m-phenylene diamine) appeared to undergo rather rapid hydrolysis initially, but the reaction had essentially halted by the time the measured imide content had decreased by 5-6%. Polymers based on 3,3 ,4,4 -biphenyl tetracarboxylic acid dianhydride (with p-phenylene diamine) and pyromellitic dianhydride (with oxydianiline) showed no significant imide hydrolysis. In all the polymers, the anhydride was hydrolyzed quite readily. 

The polyamic acids were prepared in these laboratories using modifications of a standard preparation (7). Benzophenone tetracarboxylic acid dianhydride (BTDA), benzenetetracarboxylic acid dianhydride (pyromellitic dianhydride PMDA), oxydianiline (ODA), 1,4-phenylenediamine (PDA) and 1,3-phenylenediamine (MPDA) were all obtained from Aldrich Chemical Co. The S -biphenyl tetracarboxylic acid dianhydride (BPDA) was obtained from Ube Chemical Company. The polyamic acids were prepared in N-methylpyrrolidinone (BTDA-ODA, BTDA-MPDA and BTDA with a 1 1 molar ratio of MPDA and ODA) or dimethyl acetamide (BPDA-PDA and PMDA-ODA). 

A mixture of diamines is added to an alcoholic solution of the half ester of benzophenone tetracarboxylic acid and reacted to form a heavy syrup. This S5uiip is heated to form a PI precursor resin. Eventually, the precursor is pulverized into a powder which is... 

The tetraester of benzophenone-tetracarboxylic acid has found application as nonmigrating plasticizer of polyvii rlchloride. ... 

A monomer mixture composed of an ester of benzophenone tetracarboxylic acid and a polyamine, with a content of 9% volatiles, is heated to a critical temperature at which foaming occurs contemporaneously with polymerization of the tetracarboxylic and polyamine components until the PI foam is formed [78],... 

The extension of this reaction to tetrafunctional monomers (e.g., pyromelittic acid anhydride or benzophenone tetracarboxylic acid anhydride), results in the formation of polyimides. 

PAA/PAE Blends. PAAs and PAEs were blended and dissolution rate of their films was measured. Some of the mixture films were peeled off from the substrate during the dissolution. The results for two examples of the mixtures are shown in Figure 2. It can be seen from Figure 2 that the dissolution rate of the films for blends increases with the content of PAA as expected. We selected a polymer of blend ratio of PAA/PAE 50/50 for PAA(BTDA/DDE)/PAE(BTD-Me/DDE) as a base polymer with moderate dissolution rate, where BTDA is benzophenone tetracarboxylic acid dianhaydride, DDE is diphenyldiaminoether, and BTD-Me is benzophenone tetracarboxylic acid dimethyl ester. The exposure characteristic for a photosensitive material composed of the blend as a base polymer and TBP-DNQ... 

The synthetic route for preparing the addition polyimide adhesive LARC-13 is displayed in Fig. 1. Appropriate quantities of 3,3 -methylenedianiline (m,m -MDA)f nadic anhydride (NA), and 3,3, 4,4 -benzophenone-tetracarboxylic acid dianhydr ide (BTDA) are combined in an amide solvent at a concentration of 50% solids by weight to form a 1300 molecular weight amic acid. This amic acid prepolymer is used as the adhesive resin and is later cured to the cross-linked polyimide by the removal of solvent,... 

Polyimides are also obtained in one step in the reaction of diisocyanates with tetracarboxylic acid dianhydrides. As an example, BTDA is reacted with a mixture of 2,4-TDI and MDI in DMF (93). This copolyimide, PI 2080, is used as a high temperature fiber and it is also sinter molded into solid shapes with exceptional mechanical properties. From PMDI and benzophenone-tetracarboxylic acid dianhydride polyimide foams with outstanding thermal properties and flame resistance are produced (94). Pol5fimides derived from p-phenylene diisocyanate (PPDI) or naphthalene diisocyanate (NDI) and pyromellitic dianhydride or BTDA are also synthesized using DMAc as solvent (95). 

Chow et al. investigated the isoimide to imide conversion process with commercial Larc-TPI samples [25]. As illustrated in Fig. 11, the reaction of 3,3, 4,4 -benzophenone tetracarboxylic acid dianhydride 18 and 3,3 -carbonylbisbenze-neamine 19 leads to polyamic acid 20. Dehydrocyclisation to poly(isoiniide) 21 is then performed in solution by adding dicyclohexylcarbodiimide (DCC) or trifluoroacetic acid anhydride. Polymer 21 is generally processed fi om its solutions in polar organic solvents, dried and converted to polyimide 22 by thermal isomerisation. 

Synthetic studies on the preparation of polyimides via the imidization route together with characterization studies have been made on systems derived from bis(4-amino-3-methoxyphenyl)methane and pyrazine tetracarboxylic acid, m- and p-carboranylenediamines and tetracarboxylic acids, and aromatic diamines and a new class of dianhydride monomers. Copolymers have also been prepared from the reaction of 3,3, 4,4 -benzophenone tetracarboxylic acid dianhydride with 3,3 -sulphonyl bis(phenylisocyanate) and 4,4 -sulphonyl bis(phenylisocyanate). ... 

Methacrylate esters containing residual carboxylic acid groups were prepared by the reaction of hydroxyethylmethacrylate with phthalic anhydride, pyromellitic dianhydride, and benzophenone tetracarboxylic acid dianhydride. The residual acid provided improved adhesion.[149], [150] The reaction product of hydroxyalkylmethacry-lates with maleic anhydride also produced monomers with residual acid as well as additional curable unsaturation [151]. 

Monomers Pyromellitic dianhydride (PMDA), 4,4 -oxdiphthalic anhydride (ODPA)" and 3,3 ,4,4 -benzophenone tetracarboxylic acid dianhydride (BTDA) were sublimed at 215°C at less than 1 torr. A research dianhydride, bis[p-(3,4-dicarboxyphenoxy)phenyl] sulfone dianhydride (BSDA), was also used. The diamines presented in Table I with literature references were purified by recrystallization before use. 

NASA-Langley Research Center. The characteristics of the samples in the two sets are given in Table I. The first set of samples were lap-joints of Pasa-Jell cleaned Ti-6-4 panels bonded with one polyimide resin adhesive. The resin adhesive was prepared from benzophenone tetracarboxylic acid dianhydride (BTDA) and m,m -diaminobenzophenone (m,m DABP). The structures of these compounds are given in Table II. The uncured adhesive was applied on the adherend in the polyamic acid stage from either diglyme or DMAC solution and then heat cured to the polyimide resin form. This condensation polymerization reaction is shown below. 

STRUCTURES OF RESIN STARTING MATERIALS BTDA = benzophenone tetracarboxylic acid dianhydride... 

The idea of synthesizing imide oligomers which carry acetylenic terminations appeared attractive because homopolymerization through acetylenic endgroups occurs without any volatile evolution and provides materials with good properties. Landis et. al (8,9) published the synthesis of such acetylene terminated imide oligomers from benzophenone tetracarboxylic anhydride, aromatic diamine and 3-ethynylaniline via the classical route. As usual, the amide acid is formed as an intermediate which, after chemical cyclodehydration, provides the polymide. Since ethynyl-terminated polyimide is used as a matrix resin for fiber composites, processing is possible via the amide acid, which is soluble in acetone, or via the fully imidized prepolymer, which is soluble in NMP. The chemical structure of the fully imidized ethynyl-terminated polyimide is provided in Fig. 44. 

Polyimides with better viscosity characteristics have been obtained from 3,3 -diamino-4,4 -bis(dimethylamino)-benzophenone and different aromatic tetracarboxylic acid dianhydrides [21] (Scheme 3.4). 

Reactions of 3,3 -diamino-4,4 -bis(dimethylamino)-benzophenone with the dianhydrides of aromatic tetracarboxylic acids (pyromellitic, benzophenone-3,3, 4,4 -tetracarboxylic and diphenyloxide-3,3, 4,4 -tetracarboxylic acids) were carried out using a two-stage process including room temperature reaction of starting monomers in NMP, formation of PCA and subsequent cyclodehydration of the... 

Starting materials and solvents were purchased from Aldrich Chemical Co. acetonitrile (ACN), N,N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP) were obtained anhydrous in Sure/Seal bottles and used as received. The polyamic acid of PMDA-ODA (2545 Pyralin) was supplied by DuPont. The soluble polyimide XU-218, derived from 3,3, 4,4 -benzophenone tetracarboxylic dianhydride (BTDA) and diamino-1,1,3-trimethyl-3-phenylindan isomers (DAPI) was purchased from Ciba-Geigy Corp. The acetylene terminated imide oligomer powder (Thermid MC-600) derived from BTDA, aminophenylacetylene, and 1,3-bis (2-aminophenoxy) benzene (APB) was obtained from National Starch and Chemical Company. Kapton Type II (PMDA-ODA) films were obtained from DuPont Co., Apical polyimide films were obtained from Allied Corp., and Upilex Type-S and Type-R polyimide films derived from 3,3, 4,4 -biphenyl tetracarboxylic dianhydride (BPDA) plus p-phenylenediamine (PDA) and ODA, respectively were obtained from ICI Americas Inc. 

Sulfur tetrafluoride fluorination of aryl perfluoroalkyl esters provides a route to stable aryl perfluoroalkyl ether compounds (1). By using nitrophenyl esters of perfluoroalkyl-ene and perfluoroalkylene ether dicarboxylic acids, a, w-bis (m-nitrophenoxy) perfluoroalkylene ether intermediates were prepared. The conversion of these products to the corresponding amino and isocyanatophenoxy derivatives is described. Reaction of the diamines with benzophenone-tetracarboxylic dianhydride resulted in formation of poly-imides. Cyclotrimerization of the diisocyanate intermediates formed polyisocyanurates. Both the imide and iso-cyanurate polymers have high thermal, oxidative, and hydrolytic stability. 

The polyimide polymers were formed by an established procedure (17) involving the addition of stoichiometric quantities of benzophenone-tetracarboxylic dianhydride (sublimed) to the diamine dissolved in anhydrous dimethylacetamide. The polyamic acid solution was cast on Teflon, warmed (80° to 90°C) to drive off solvent, then gradually heated to a temperature of 180°C. The polyimide forms rapidly at 120 to 150°C. 

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