Pyromellitic dianhydride oxydianiline PMDA-ODA

Abstract—The adhesion of pyromellitic dianhydride-oxydianiline (PMDA-ODA) polyimide to fluorine-contaminated silicon dioxide (F-SiO,) with y-aminopropyllriethoxysilane (APS) adhesion promoter has been studied as a function of the peel ambient humidity. The peel strength was not affected by the change in peel ambient relative humidity (RH) from 11-17% to 35-60% when APS was used at the interface. Without APS, the adhesion degraded significantly with this change in RH. It was found that although the dip application of APS caused the removal of about 80% of the initial atomic percentage of fluorine on the surface, it could not be totally removed even after several days in water at elevated temperature. 

Adhesion of polyimides to inorganic substrates is of great importance to the microelectronics industry [1, 2]. The polyimide films are deposited most often by spin coating the polyamic acid (PAA) usually from a TV-methylpyrrolidone (NMP) solution onto the substrate surface followed by thermal imidization at temperatures up to 400<>C. The most studied polyimide is the pyromellitic dianhydride-oxydianiline (PMDA-ODA), which exhibits excellent mechanical and dielectric properties, but not so good adhesion characteristics. The latter has been generally overcome by application of an adhesion promoter, such as y-aminopropyltriethoxysilane [3-7]. The reactions of APS (coated from water solution) with the silicon dioxide surface as well as with polyamic acid have been well characterized by Linde and Gleason [4] however, we do not have such detailed information available on APS interaction with other ceramic surfaces. 

Polyimide surface modification by a wet chemical process is described. Poly(pyromellitic dianhydride-oxydianiline) (PMDA-ODA) and poly(bisphenyl dianhydride-para-phenylenediamine) (BPDA-PDA) polyimide film surfaces are initially modified with KOH aqueous solution. These modified surfaces are further treated with aqueous HC1 solution to protonate the ionic molecules. Modified surfaces are identified with X-ray photoelectron spectroscopy (XPS), external reflectance infrared (ER IR) spectroscopy, gravimetric analysis, contact angle and thickness measurement. Initial reaction with KOH transforms the polyimide surface to a potassium polyamate surface. The reaction of the polyamate surface with HC1 yields a polyamic acid surface. Upon curing the modified surface, the starting polyimide surface is produced. The depth of modification, which is measured by a method using an absorbance-thickness relationship established with ellipsometry and ER IR, is controlled by the KOH reaction temperature and the reaction time. Surface topography and film thickness can be maintained while a strong polyimide-polyimide adhesion is achieved. Relationship between surface structure and adhesion is discussed. 

Creep rate spectroscopy technique turned out to be very useful for comparative estimation high-temperature performance of such valuable polymers with increased chain rigidity such as PI. The bulk of commercial PI materials rely on solvent-based fabrication techniques. However, parts and shapes, formed from dry PI resin such as pyromellitic dianhydride-oxydianiline (PMDA-ODA), have been commercially available in the last few decades from Du Pont (Vespel ). Due to their excellent temperature (up to 300-350°C), mechanical, solvent and wear resistances, these parts have achieved wide acceptance in different demanding technical applications under extremely high temperatures. 

Abstract—The effects of both y-aminopropyltriethoxysilane (APS) and elevated temperature and humidity (T H) exposure on the adhesion of pyromellitic dianhydride-oxydianiline polyimide to SiO , AkOi, and MgO were studied using XPS, SEM, and peel test. Adhesion and T H stability of PMDA-ODA on Si02 is significantly improved when APS is used at the interface, while no significant improvement is observed for AkO, or MgO. XPS analysis of the surfaces showed no retention of APS on AkO, or MgO, while Si02 did retain APS, as is expected. The APS retention is affected by surface treatment of the oxide prior to APS application. 

The interactions between metals and polymers are good examples of the applications of the HSAB principle to solids. When Cr is deposited on pyromellitic dianhydride oxydianiline polyimide (PMDA-ODA P/), there appears to be some chemical bonding between Cr and PI, In this case, Cr is a "soft" acid, and P/ is "hard base. How can the bonding take place According to Ho et al. indeed the reaction does not proceed in the... 

Hedrick et al. reported imide aryl ether ketone segmented block copolymers.228 The block copolymers were prepared via a two-step process. Both a bisphenol-A-based amorphous block and a semicrystalline block were prepared from a soluble and amorphous ketimine precursor. The blocks of poly(arylene ether ether ketone) oligomers with Mn range of 6000-12,000 g/mol were coreacted with 4,4,-oxydianiline (ODA) and pyromellitic dianhydride (PMDA) diethyl ester diacyl chloride in NMP in the presence of A - me thy 1 morphi 1 i nc. Clear films with high moduli by solution casting and followed by curing were obtained. Multiphase morphologies were observed in both cases. 

Aromatic polyimides have excellent thermal stability in addition to their good electrical properties, light weight, flexibility, and easy processability. The first aromatic polyimide film (Kapton, produced by DuPont) was commercialized in the 1960s and has been developed for various aerospace applications. The structure of a typical polyimide PMDA/ODA prepared from pyromellitic dianhydride (PMDA) and 4,4 -oxydianiline (ODA), which has the same structure as Kapton, is shown in (1). Aromatic polyimides have excellent thermal stability because they consist of aromatic and imide rings. 

The two-step poly(amic acid) process is the most commonly practiced procedure. In this process, a dianhydride and a diamine react at ambient temperature in a dipolar aprotic solvent such as N,N- dimethyl acetamide [127-19-5] (DMAc) or N-methylpyrrolidinone [872-50 4] (NMP) to form apoly(amic acid), which is then cyclized into the polyimide product. The reaction of pyromellitic dianhydride [26265-89 4] (PMDA) and 4,4 -oxydianiline [101-80-4] (ODA) proceeds rapidly at room temperature to form a viscous solution of poly(amic acid) (5), which is an ortho-carboxylated aromatic polyamide. 

Polyimides have excellent dielectric strength and a low dielectric constant, but in certain electrolyte solutions they can electrochemically transport electronic and ionic charge. Haushalter and Krause (5) first reported that Kapton polyimide films derived from 1,2,4,5-pyromellitic dianhydride (PMDA) and 4,4 -oxydianiline (ODA) undergo reversible reduction/oxidation (redox) reactions in electrolyte solutions. Mazur et al., (6) presented a detailed study of the electrochemical properties of chemically imidized aromatic PMDA- derived polyimides and model compounds in nonaqueous solutions. Thin films of thermally... 

One commonly used polyimide is poly(N,N -bis(phenoxyphenyl)-pyromellitimide). This may be prepared from the reaction of pyromellitic dianhydride (PMDA) and oxydianiline (ODA) in a two step process (Figure 1). The first step involves a solution reaction forming the poly(amic acid) (PAA). After solvent removal this material can be thermally cyclized to the polyimide (PI). To improve properties, it is often annealed at temperatures up to 400° C. 

Poly(imides) contain the group -C(0)-NH-C(0)- in their structure. Many poly(imides) with practical applications have a more complicated formula and contain oxygen atoms and aromatic rings in the backbone [1]. One example is poly(pyromellitic dianhydride-a/f-4,4 -oxydianiline) or PMDA-ODA, CAS 25038-81-7, which is obtained from pyromellitic anhydride and oxybis(benzenamine) by water elimination as follows ... 

Fluorescence spectra of polyimide as a function of thermal history for two of the most common commercially available polyimide precursors, Du Pont PI-2545 and PI-2555, were obtained. These precursors are polyamic acids formed from the polycondensation reaction of pyromellitic dianhydride (PMDA) and oxydianiline (ODA),... 

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). 

Through the synthesis of poly(urethane-imide) films and their carbonization, carbon films were obtained whose macropore structure could be controlled by changing the molecular structure of polyurethane prepolymer [164-166]. Poly(urethane-imide) films were prepared by blending poly(amide acid), which was synthesized from pyromellitic dianhydride (PMDA) and 4,4 -oxydianiline (ODA), and phenol-terminated polyurethane pjrejwlymers, which were synthesized through the reaction of polyester polyol with either hexamethylene diisocyanate (HDI), tolylene-2,4-diisocyanate (TDI) or 4,4 -diphenyknethane-diisocyanate (MDI). The reaction schemes of two components, poly(imide) (PI) and poly(urethane) (PU), are shown in Fig. 46a). 

PAN, polyacrylonitrile PP, polypropylene PPSU, polyphenylsulfone PPBES, copoly(phthalazinone biphenyl ether sulfone) PPESK, poly(phthalazinone ether sulfone ketone) PPENK, poly(phthalazinone ether nitrile ketone) PMDA/ODA PI, poly(pyromellitic dianhydride-co-4,4 -oxydianiline). 

In 2003, Yang et al. first reported the method of carbon fiber preparation by carbonizing the electrospun PI fibers (Yang et al, 2003). They discussed the parameters for the PI electrospinning, pointing out the proper concentrations and viscosity of the solutions, as well as the voltage and electric field. Their job provided precious experience for the followup works. In their work, 4,4 -oxydianiline (ODA) and pyromellitic dianhydride (PMDA)... 

Suda and Haraya [10] were successful in preparation of flat, asynunetric carbon molecular sieve membranes, which exhibited the highest gas permselectivities among those fabricated in the past research by pyrolysis of a Kapton type PI derived from pyromellitic dianhydride (PMDA) and 4,4 -oxydianiline (ODA). They used the permeation measurements and X-ray powder diffraction to relate the relationship between the gas permselectivity and microstucture of the CMSM. They proposed that the decrease of the interplanar spacing, amorphous portion and pores upon heating might be the origin of the molecular sieving effect . 

Fig. 33.6 fhe polyimide structures of (a) BTDA-ODA (3.3. 4,4 -benzophenonetctracarboxylic dianhydride 4,4 -oxydiani-line), (b) PMDA-ODA (pyromellitic dianhydride 4.4 -oxydianiline). and (c) 6FDA-ODA (2.2-bis(.3.4-dicarboxyphenyl)hex-atluoropropane dianhydride 4,4 -oxydianilinel. 

Cu-BTC (Figure 5b) was spun into MMM hollow fibers with a polyimide prepared from 4,4-oxydianiline (ODA) and pyromellitic dianhydride (PMDA). Hydrogen, H2 permeance, and selectivity of H2 with respect to N2, CO2, O2, and CH4 increased with increased Cu-BTC loading. At 6 wt% Cu-BTC, the permeance of H2 was higher by 45%, and its ideal selectivity from other gases was up by a factor of 2-3 compared to pure polyimide. 

CNT = carbon nanotube GPU = gas permeation unit MMM = mixed-matrix membrane MOF = Metal organic framework ODA = 4,4-oxydianiline PFG = pulsed field gradient PLO = porous layered oxide PMDA = pyromellitic dianhydride PPEES = poly-( 1,4-phenylene ether-ether-sulfone) ... 

Materials. TEOS (tetraethoxy silane, Aldrich), Ultradel 1414 (PAA from Amoco), ODA (oxydianiline, Aldrich) and APTCS (3-aminopropyltriethoxyl silane, Aldrich) were used as received without further purification. DMF (Aldrich), THE (Aldrich), NMP (Aldrich) and acetonitrile (Aldrich) were dried over magnesium sulfate and stored over molecular sieve 4 A. PMDA (pyromellitic dianhydride, Aldrich) was recrystallized three times from dry acetone and sublimed at least three times under vacuum. 

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