38103-05-8

Upstream product

• 38791-67-2 4,4'-isopropylidendioxydiphthalonitrile 
• 80-05-7 BPA 
• 40392-27-6 4-nitro-N-phenylphthalimide 
• 54395-52-7 4,4’-bisphenol A-bis-N-methylphthalimide 
• 41663-84-7 4-nitro-N-methyl-phthalimide 
• 31643-49-9 4-Nitrophthalonitrile 

Downstream Products

• 38103-06-9 4,4'-bis(4,4'-isopropylidene diphenoxy)-bis(phthalic anhydride) 

Relevant academic research and scientific papers

Polyetherimides for gas separation membranes

A series of polyetherimides were synthesized by polycondensation reaction at high temperature of 2,2-bis[4,4-(3,4-dicarboxyphenoxy) phenyl]propane dianhydride with various aromatic diamines. These polymers are easy soluble in polar aprotic solvents such as N-methylpyrrolidinone, dimethylformamide or dimethylacetamide or even in less polar liquids such as chloroform. They show high thermal stability, with decomposition temperature being above 400°C and glass transition temperature in the range 200-275°C. Polymer solutions in chloroform were processed into thin films which were tested as gas separation membranes. Transport parameters for light gases were measured. The dependence of glass transition and decomposition temperature on conformational rigidity parameters was calculated.

METHODS OF MANUFACTURE OF DIANHYDRIDES

A method of making dianhydride includes contacting a N-Substituted diimide with a carboxylic acid and substituted or unsubstituted dimethyl sulfoxide in an aqueous medium to provide a reaction mixture including tetra acid, triacid, imide diacid and diimide along with substituted or unsubstituted acetic acid, dimethyl sulfoxide and their derivatives. The method includes the isolation of tetra acid by precipitation in water followed by centrifuge or filtration. The tetra acid is converted into the corresponding dianhydride. The dianhydride prepared by the method are also described as precursor to make polyetherimide.

Preparation method of aromatic diether dianhydride

The invention relates to a preparation method of aromatic diether dianhydride, which comprises the following steps: (1) pouring a bisphenol compound, N-substituted phthalimide and a catalyst into a mixed solvent, carrying out heating reflux to remove water and carrying out substitution reaction to obtain N-substituted diether imide; (2) adding alkali metal hydroxide and water into the N-substituted diether imide obtained in the step (1), heating the mixture, carrying out hydrolysis reaction, cooling, adding protonic acid, separating out solid, collecting the solid, and drying the solid; and (3) dissolving the dried solid in a mixed solution of acetic acid and acetic anhydride, carrying out heating reflux, cooling, filtration and solid collection in sequence, recrystallizing the collected solid with a mixed solution of acetonitrile and toluene, performing filtration, collecting the solid, and drying the solid to obtain the product. The preparation method of the aromatic diether dianhydride has the advantages that the steps are simplified, the consumed time is short, the used solvent is easy to recycle and can be repeatedly used, and the prepared product aromatic diether dianhydrideis high in purity and yield.

A comparison of poly(ether imide)s with 3-phthalimide and 4-phthalimide units: Synthesis, characterization, and physical properties

Bis(ether anhydride)s with 3- or 4-phthalimide moieties were prepared by reacting 3- or 4-nitrophthalodinitrile, respectively, with several diols and converting the resulting bis(ether dinitrile)s to bis(ether anhydride)s. Selected dianhydrides were converted into poly(ether imide)s in a two-stage solution polymerization and imidization process. It was found that, in most cases, the dianhydrides with 4-phthalic anhydride units gave high-molecular-weight polymers with any of several aromatic diamines. In contrast, dianhydrides with 3-phthalic anhydride units gave, primarily, low-molecular-weight products. Examination of several low-molecular-weight products by electrospray-ionization mass spectrometry demonstrated that the products consisted of small oligomers, cyclic or linear according to the structure of the diamine. A series of high-molecular-weight polymers were prepared from 4,4′-bis(4″-aminophenoxy)biphenyl (BAPB) and each of several bis(ether anhydride)s with 3- or 4-phthalic anhydride units; the anhydrides had isopropylidine or hexafluoroisopropylidine units or ortfto-methyl or ortho-tert-butyl substituents in the diol residues. These polymers were characterized in terms of their molecular weights and glass-transition temperatures. The gas permeabilities, positron annihilation, and dielectric relaxation behaviors of the polymers were investigated and their properties related to their molecular structures. Dielectric relaxation spectroscopy measurements indicate that, in this group of polymers, the rates of the local chain mobility are comparable and are able to facilitate gas diffusion. An apparent linear correlation between the permeation coefficients and free volume as determined by positron annihilation lifetime spectroscopy was observed with certain gases. Comparison of polymers with similar molecular structures indicated that isomeric polymers with 3- and 4-linked phthalimide units have similar properties and that the introduction of branched chains or fluorinated groups leads to an increase in the free volume and consequently increased permeability.

Method for making aromatic bis(ether dicarboxylic acid)

A method is provided for making aromatic bis(ether dicarboxylic acid) useful for making high performance injection moldable polyetherimides. An aromatic bis(ether N-organo phthalimide) is hydrolyzed directly to the corresponding tetra-acid by heating the aromatic bis(ehter N-organo phthalimide) in a closed system in the presence of acetic acid, water, and a mineral acid.

Method for making aromatic bis(ether dicarboxylic acid)s

A method is provided for making aromatic bis(ether dicarboxylic acid)s, such as 2,2-bis[4(3,4-dicarboxyphenoxy)phenyl] propane. The corresponding aromatic bis(etherimide) is hydrolyzed in base to produce a tetraacid salt which is directly acidified with concentrated mineral acid such as sulfuric acid. The resulting aqueous mixture containing a paste is heated to produce the aromatic bis(ether dicarboxylic acid) in ready filterable form.

Method of making aromatic bis(ether ortho phthalic acid)s

Aromatic bis(ether anhydride)s can be made by a nitro displacement of an N-substituted nitrophthalimide with an alkali diphenoxide to produce an intermediate aromatic bis(etherphthalimide). Hydrolysis of the aromatic bis(etherphthalimide) to the corresponding tetra-acid salt followed by acidification and dehydration, results in the production of the aromatic bis(ether anhydride). These anhydrides can be used as intermediates for making polyimides. The intermediate aromatic bis(etherphthalimide) can be employed as a plasticizer in polyimide resins.