3,3 -4,4 -Benzophenonetetracarboxylic acid dianhydride

Ultraviolet autocurable semicrystalline prepolymers have been synthesized from 3,3, 4,4 -benzophenonetetracarboxylic acid dianhydride-glycidyl acrylate-hydroxyethylacrylate-polycaprolactone... 

A series of 15 wt % isomeric polyimide precursor resin solutions was prepared by the National Aeronautics and Space Administration Langley Research Center. The polymerization procedure has been described previously (2,3). The poly(amic-acid) resin solutions were made from 3,3, 4,4 -benzophenonetetracarboxylic acid dianhydride (BTDA), 4,4 -oxydiphthalic anhydride (ODPA), diaminobenzophenone (DABP), and methylenedianiline (MDA) monomers. 

The polyamic acid (EQ) precursor (Fig. 4.15) was prepared by adding stoichiometric amounts of 3,3,4,4-benzophenonetetracarboxylic acid dianhydride (BTDA) and diaminodiphenylsulfone (DDS). The solution highly concentrated in NMP was then submitted to either thermal or MW activation with accurate monitoring of the temperature (Scheme 4.18). 

During the last several years, a thermoplastic condensation polyimide (PI) was developed at NASA Langley Research Center (49). Prom the reaction between BTDA (3,3, 4,4 -benzophenonetetracarboxylic acid dianhydride) and DABP (3,3 -diamino benzophenone), the polyimide LARC-TPI (Pig. 7) was prepared by Bell et al. (49). Later, St. Clair (50) used LARC-TPI as an adhesive for titanium. The adhesion of titanium and PI has been studied by Nightman et al. (51) with XPS (ESCA) and PT-IR techniques. 

Figure 11 Reaction of 3,3, 4, 4 -benzophenonetetracarboxylic acid dianhydride (BTDA) 18 with 3,3 -carbonylbisbenzeneamine 19 in the presence of dicyclohexylcarbodiimide (DCC) leading to polyisomide (polyiminolactone) 21 via the intermediate polyamic acid 20. Isoimide-imide conversion predominantly occurs by heating polymer 21 at 300°C, followed by a final excursion at 350-400°C.

Chow et al. investigated the isoimide to imide conversion process with commercial Larc-TPI samples. As illustrated in Fig. 9.11, the reaction of 3,3, 4, 4 -benzophenonetetracarboxylic acid dianhydride 18 and 3,3 -carbonylbisbenzeneamine 19 leads to polyamic acid 20. Dehydrocyclization to poly-isoimide 21 is then performed in solution by adding... 

Rather similar are the 5.5-dimethylhydantoin derivatives shown in Figure 26.18 (b, e). These resins are said to eonfer improved weathering resistance but also exhibit higher water absorption. Another trifunctional material is p-glycidyl-oxy-A,A/-diglycidylaniline. This has been recommended for adhesive systems in conjunction with benzophenonetetracarboxylic acid dianhydride, which is a room temperature curing agent in this case. 

None of the polyimides synthesised dissolve in amide solvents, including NMP. Moreover, the polyimide prepared from 3,5-diaminoanisole and diphenyloxidetetracarboxylic acid dianhydride is soluble in OT-cresol and a mixed trichloroethane/phenol (3 1) solvent, whereas the polypyromelliteimide and polyimide based on benzophenonetetracarboxylic acid dianhydride do not dissolve in these phenolic solvents. 

Reaction polymerization reactions of isocyanates with suitable monomers can he performed in an extruder or in a RIM machine. In the latter reaction thermosets (cross-hnked polymers) are produced. In an extruder usually linear polymers are manufactured. For example from methylene di-p-phenylene isocyanate (MDI), with some macroglycols and 1,4-hutanediol as extenders, segmented polyurethane elastomers are produced in an extruder (6). However, linear condensation polymers are also produced in a vented extruder. For example from MDI, with macrodicarboxylic acids and dicarboxyhc acids as extenders thermoplastic block copolyamide elastomers are produced. The by-product of the condensation reaction, carbon dioxide, is removed in the vented extruder. The polycondensation process can also be performed in solution. For example, MDI can be added to a solution of dicarboxyhc acids in tetramethylene sulfone, with simultaneous removal of the carbon dioxide. Tetramethylene sulfone is the solvent of choice for solution polymerization of isocyanates (7). In addition to dicarboxyhc acids trimellitic acid anhydride and benzophenonetetracarboxylic acid dianhydride (BTDA) are utilized as monomers for condensation polymers. With these monomers poly(amide imides) and poly(imides) are produced. The diisocyanate-derived commercial polycondensation products are listed in Table 1. 

MDI, TDI Benzophenonetetracarboxylic acid dianhydride Poly(imide) fibers and films... 

Figure 52 Polycondensation of 4,4 -benzophenonetetracarboxylic acid dianhydride 102 with 4,4 -methylenebisbenzeneamine 112 and a,o)-diaminopolydimethylsiloxane 113 leading to intermediate polyamic acid recurring units 114a and 114b whose thermal cyclodehydration leads to a poly(imide-siloxane) formed of repeating units...

Up to the decomposition temperature, polypyromelliteimide based on 3,5-diaminoanisole does not soften. The softening points of polyimides prepared from benzophenonetetracarboxylic and diphenyloxidetetracarboxylic acid dianhydrides are 300 and 310 °C, respectively, (Table 5.1). 

Linear PC[23] 1,1,1 -tri(4-hydroxy-phenyl) ethane, 2,2 5,5 -tetra(4-hydroxypheny 1) hexane, trimellitic anhydride, trimellitic acid, trimellitoyl trichloride, 4-chloroformyl phthalic anhydride, pyromellitic acid, pyromellitic dianhydride, mellitic acid, mellitic anhydride, trimesic acid, benzophenonetetracarboxylic acid and benzophenonetetracarboxylic anhydride (0.1-10 % by weight) 100-400 Increased branching and crosslinking... 

The use of monomethacrylates in anaerobic formulations was disclosed in a patent assigned to Loctite. Specifically mentioned were hydroxyethyl (XIX), hydroxypropyl (XX), cyclohexyl (XXI), tetrahydrofurfuryl (XXII), dimethylaminoethyl (XXIII), and glycidyl methacrylates (XXIV), and cyanoethyl acrylate [26]. Methacrylate esters containing residual carboxylic add groups were prepared by the reaction of hydroxyethyl methacrylate with phthalic anhydride (XXV), pyromellitic dianhydride (XXVI), and benzophenonetetracarboxylic add dianhydride (XXVII). The residual acid provided improved adhesion [27,28]. The reaction product of hydroxyalkylmethacrylates with maleic anhydride (XXVIII) also produced monomers with residual acid as well as additional curable unsaturation [29]. The dimethacrylates of the bisglycol esters of dicarboxylic adds were used to formulate anaerobic adhesives. Among the dicarboxylic acids mentioned were phthalic (XXIX), maleic (XXX), fumaric (XXXI), and malonic (XXXII) [30]. 

Materials. 3,3, 4,4 -Benzophenonetetracarboxylic dianhydride (BTDA), 4,4 -methylenedianiline (MDA), p-aminobenzonitrile (PABN), and p-toluenesulfonic acid monohydrate (PTSA) were of commercial sources and used as received. Graphite fiber used as the reinforcing filler was Hercules HMS grade. 

In a 250 ml flask, 2,98 g of bis(p-diaminophenyl)ether was dissolved in 35 ml DMF using mechanical stirring. Then added dropwise 2,4l6 g of 3 3AA-benzophenonetetracarboxylic dianhydride (dissolved in 40 ml DMF) over a period of 100 minutes.Then 1.47 g of maleic anhydride was slowly added, maintained not over 20 C. The resulting MPE amic acid was precipitated in water, filtered and washed with water, dried.MPE amic acid was characterized by Infra-red, DSC and Elemental analysis. 

A copolycondesation-type poly (amic acid) was synthesized using pyromellitic dianhydride and 3,3, 4,4 -benzophenonetetracarboxylic dianhydride as dianhydride monomers, and 4,4 -oxydianiline as a diamine monomer under microwave irradiation in dimethylformamide. PAA was then converted into a polyimide by an imidization (Li et al., 2008). 

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