Synthesis of poly(propylene glycol)‐grafted polyimide precursors and preparation of nanoporous polyimides

A novel approach to prepare a polyimide nanofoam was explored by using a polyimide precursor grafted with a labile poly(propylene glycol) (PPG) oligomer. The PPG‐grafted polyimide precursor, poly((amic acid)‐co‐(amic ester)), was synthesized via partial esterification of poly(amic acid) derived from pyromellitic dianhydride (PMDA) and 4,4′‐oxydianiline (ODA) with bromo‐terminated poly(propylene glycol) in the presence of K₂CO₃ in hexamethylphosphoramide and N‐methylpyrrolidone. The precursor polymer film was spin‐coated onto a glass substrate, then imidized at 200 °C under nitrogen, and subsequently the PPG graft was decomposed by heating the film at 300 °C for 9 h in air, resulting in the PMDA/ODA polyimide nanofoam. The precursor polymers, polyimides and foamed polyimides were characterized by a variety of techniques including ¹H‐NMR spectroscopy, Fourier‐transform infrared (FT‐IR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The homogeneously distributed nano‐sized pores of 20–40 nm were observed by transmission electron microscopy (TEM) of the foamed polyimide. Copyright © 2004 Society of Chemical Industry     

Water‐sorption behavior of P‐phenylene diamine–based polyimide thin films

Four different p‐PDA–based polyimide thin films were prepared from their respective poly(amic acid)s through thermal imidization at 400°C: poly(p‐phenylene pyromellitimide) (PMDA‐PDA); poly(p‐phenylene biphenyltetra carboximide) (BPDA‐PDA); poly(p‐phenylene 3,3′,4,4′‐oxydiphthalimide) (ODPA‐PDA); and poly(p‐phenylene 4,4′‐hexafluoroisopropylidene diphthalimide) (6FDA‐PDA). Water‐sorption behaviors of polyimide films were gravimetrically investigated at 25°C and 22–100% relative humidity by using the modified electromicrobalance (Thin Film Diffusion Analyzer). The diffusion coefficients of water for the polyimides varies in the range of 1.6 to 10.5 × 10⁻¹⁰ cm²/s, and are in the increasing order: BPDA‐PDA < PMDA‐PDA ∼ ODPA‐PDA < 6FDA‐PDA. The water uptakes of polyimides vary from 1.46 to 5.80 wt %, and are in the increasing order: BPDA‐PDA < ODPA‐PDA < 6FDA‐PDA < PMDA‐PDA. The water‐sorption behaviors for the p‐PDA–based polyimides are closely related to the morphological structure; specifically, the diffusion coefficients in p‐PDA–based polyimide thin films are closely related to the in‐plane orientation and mean intermolecular distance, whereas the water uptakes are affected by the packing order. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1315–1323, 2000     

Membrane color and gas permeability of 6FDA‐TeMPD polyimide membranes prepared with various membrane preparation protocols

The relations among polyimide membrane colors, their gas transport and separation properties, and their fluorescence spectra were systematically investigated using fluorine‐containing aromatic polyimide, 6FDA‐TeMPD {[4,4‐(hexafluoroisopropylidene) diphthalic anhydride] [(6FDA)‐2,3,5,6‐tetramethyl‐1,4‐phenylene‐diamine (TeMPD)]}, which was used in electronic device and gas separation materials. Different molecular ordering structures of 6FDA‐TeMPD polyimides were prepared by controlling kinds of casting solvents and dry conditions. This difference was based on the effect of charge transfer (CT) interaction formed by π electrons of ring structures in polyimide. Membrane color measured using spectrophotometer determined colors as intrinsic parameters without sample collection. The permeability coefficients of oxygen and nitrogen of the 6FDA‐TeMPD polyimide membranes were correlated with membrane color index parameters such as L*, a*, b*, and ΔE*, and fluorescence properties such as maximum peak emission wavelength λ_max and intensity I_max, which reflect molecular ordering affected by CT interaction in polyimide membranes. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Preparation of soluble copolyurethaneimide containing oxyethylene and oxypropylene units

Soluble copolyurethaneimides were synthesized by the isocyanate method in a solution of N‐methyl‐2‐pyrrolidone (NMP). The isocyanate‐terminated prepolyurethane prepared from low molecular weight poly(ethylene glycol) (PEG) or poly(propylene glycol) (PPG) and methylene diisocyanate was reacted with pyromellitic dianhydride at high temperature. The resulting copolyurethaneimides were soluble in polar solvents like N‐methyl‐2‐pyrrolidone and N,N'‐dimethylformamide. The film‐forming properties were investigated by changing the molecular weights of PEG and PPG. With PPG, the film‐forming property was enhanced. The inherent viscosity, solubility, thermal property, molecular weight distribution, and mechanical property were compared with the aromatic polyimide. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3502–3507, 2002     

Aromatic/cycloaliphatic polyimides and polyamide‐imide from trans‐1,4‐cyclohexane diisocyanate: synthesis and properties

Mixed aromatic/alicyclic polyimides were prepared by polycondensation reactions of trans‐1,4‐cyclohexane diisocyanate (CHDI) with pyromellitic dianhydride (PMDA), benzophenonetetracarboxylic dianhydrid (BTDA), and hexafluoroisopropylidene diphthalic anhydride (6FDA). Also, polycondensation of CHDI with trimellitic anhydride led to synthesis of polyamide‐imide. In order to obtain the optimized condition for polymerization reactions, model compound studying was considered. Model compound and polymers were characterized by common methods. Physical properties of polymers, including thermal behavior, thermal stability, solution viscosity, and solubility behavior, were also studied. Mild polymerization condition was the main advantage of using diisocyanate instead of diamine in synthesis of these thermally stable polymers. Furthermore, synthesis of poly(amic acid) and polyimide via nonaromatic diamine can introduce synthetic problems, but by applying nonaromatic diisocyanate a facile method for preparation of aromatic/cycloaliphatic polyimides was obtained. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1102–1107, 2000     

Effect of hydrophobic hexafluoroisopropylidene group on the water sorption behaviors of rigid poly(p‐phenylene pyromellitimide) polyimide thin films

We prepared poly(p‐phenylene pyromellitimide) (PMDA–PDA), poly(p‐phenylene 4,4′‐hexafluoroisopropylidene diphthalimide), and their copolyimides with various compositions to explore the relationship between the water sorption and structure. The water sorption behaviors were gravimetrically investigated as a function of composition and temperature and interpreted with a Fickian diffusion model in films. Overall, the water sorption behaviors were strongly dependent on the changes in morphological structure, which originated from the variations in composition. When the content of the bulky hexafluoroisopropylidene group (6FDA) was increased, the water uptake decreased from 5.80 to 3.18 wt %, whereas the diffusion coefficient increased from 3.6 × 10^?10 to 11.3 × 10^?10 cm²/s. The relatively high water uptake in the PMDA–PDA polyimide film was successfully healed by the incorporation of 6FDA, which may have resulted from the increases in the intermolecular packing order and hydrophobicity. The degree of orientation and crystallinity, which are in‐plane characteristics, were directly correlated to the diffusion coefficient and activation energy in the polyimide film. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3442–3446, 2003     

Effects of the aliphatic/aromatic structure on the miscibility,thermal, optical,and rheological properties of some polyimide blends

Two binary polyimide (PI) blends having a common monomer (diamine or dianhydride) were prepared. The first system was composed of PIs obtained from an alicyclic and flexible dianhydride, namely 5‐(2,5‐dioxotetrahydrofurfuryl)‐3‐methyl‐3‐cyclohexene‐1,2‐dicarboxylic acid anhydride (DOCDA) and two aromatic diamines: 4,4′‐oxydianiline (ODA) and p‐phenylenediamine, respectively. In the second system, ODA was combined with DOCDA and (hexafluoroisopropyldiene)diphthalic dianhydride (6FDA). Films of the resulted blends were transparent, suggesting their homogeneity. According to differential scanning calorimetry data, the existence of a single T_g intermediate to those of the pure PIs confirmed the miscibility of blends. Incorporation of aliphatic and asymmetric DOCDA moieties, hexafluoropropyldiene groups and ether linkages in the molecular structure of PIs reduced the charge transfer interactions and significantly increased transparency and optical gap energy, especially for the poly(DOCDA‐ODA)/poly(6FDA‐ODA) blend. These interactions are also reflected in viscosity dependence on shear rate, indicating that they are slightly stronger when the aromatic 6FDA component prevails. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Gas transport properties in (6FDA‐RTIL)‐(6FDA‐MDA) block copolyimides

This article reports synthesis and structure property studies of block copolyimides synthesized using diamino room temperature ionic liquids (RTIL) as diamine monomers. Specifically, polyimide oligomers of different lengths were synthesized using 2,2‐bis (3,4‐carboxylphenyl) hexafluoropropane dianhydride (6FDA) and diamino RTIL (1,3‐di(3‐aminopropyl) imidazolium bis[(trifluoromethyl) sulfonyl] imide). These oligomers were copolymerized with 6FDA and m‐phenylenediamine (MDA) using in situ polymerization to form (6FDA‐RTIL)‐(6FDA‐MDA) block copolyimides. The impact of the length and relative concentration of 6FDA‐RTIL oligomer in the copolymer on the resulting thermal, physical, and gas transport properties was monitored. As the concentration of the 6FDA‐RTIL segments increased, the backbone of the block copolyimides became more flexible resulting in a decrease in the glass transition temperature (T_g) and an increase in the density. The permeabilities of the RTIL containing copolyimides were consistently lower than those of the base polyimide, 6FDA‐MDA, with some increase in selectivities. Interestingly, the permeabilities of films produced with the low molecular weight oligomers were very different than those produced with same composition of the high molecular weight oligomers. This may be indicative of very different morphologies within these copolyimides. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43077.     

Permeability of dried gases and gases dissolved in water through polyimide membranes modified by immersing in amino compound solutions

Membranes of 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA)?2,3,5,6‐tetramethyl‐1,4‐phenylene diamine (TeMPD) polyimide, a fluorine‐containing polyimide synthesized using 6FDA and TeMPD, were modified by immersing them in various amino compound solutions for application in artificial lungs. Permeabilities of dried gases (P_G) and gases dissolved in water (P_L) through the membranes were investigated. The surface reaction ratios of all the modified membranes were higher than the total reaction ratio, indicating that the modified membranes exhibited graded structures that were reacted with amino compounds from both surfaces toward the interior. Both P_L (O₂) and P_L (CO₂) of the base membrane and amine‐modified membranes, except the membrane where d ‐glucamine was used, were lower than or equal to P_G (O₂) and P_G (CO₂), respectively. Both P_L (O₂) and P_L (CO₂) of the amine‐modified membranes decreased with increasing water content, which suggests that water content strongly affected permeability in liquid phase. Results indicate that water molecules interrupted gas permeation. Moreover, CO₂/O₂ permselectivity in liquid phase increases with high‐polarity amino compounds compared with the base membrane. POLYM. ENG. SCI. 56:178–186, 2016. © 2015 Society of Plastics Engineers     

Synthesis of aromatic poly(urea‐imide) with heterocyclic side‐chain structure

The poly(urea‐imide) copolymers with inherent viscosity of 0.81–1.08 dL/g were synthesized by reacting aryl ether diamine or its polyurea prepolymer with various diisocyanate‐terminated polyimide prepolymers. The aryl ether diamine was obtained by first nucleophilic substitution of phenolphthalein with p‐chloronitrobenzene in the presence of anhydrous potassium carbonate to form a dinitro aryl ether, and then further hydrogenated to diamine. The polyimide prepolymers were prepared by using 4,4′‐diphenylmethane diisocyanate to react with pyromellitic dianhydride, 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride, or 3,3′,4,4′‐sulfonyldiphthalic anhydride by using the direct one‐pot method to improve their solubility, but without sacrificing thermal property. These copolymers are amorphous and readily soluble in a wide range of organic solvents such as N‐methyl‐2‐pyrrolidone, dimethylimidazole, N,N‐dimethylacetamide, dimethyl sulfoxide, N,N‐dimethylformamide, m‐cresol, and sulfolane. All the poly(urea‐imides) have glass transition temperatures in the range of 205–240°C and show a 10 wt % loss at 326–352°C in nitrogen and 324–350°C in air. The tensile strength, elongation at break, and initial modulus of these copolymer films range from 42 to 79 MPa, 5 to 16%, and 1.23 to 2.02 GPa, respectively. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1719–1730, 1999     

Preparation and properties of three novel poly(phosphazene‐aryl amide)s containing cyclotriphosphazene structures

1,1,3,5‐tetraphenoxy‐3,5‐bis(4‐aminoanilino)cyclotriphosphazene, 1,1,3,5‐tetraphenoxy‐3,5‐bis[4‐(4‐aminophenysulfone)anilino)]cyclotriphosphazene, and 1,1,3,5‐tetraphenoxy‐3,5‐bis(N,N′‐ethanediamine)cyclotriphosphazene were synthesized in two steps from the p‐Phenylenediamine, 4,4′‐diaminodiphenylsulfone, and ethylenediamine via nucleophilic substitution and catalytic reduction with hexachlorocyclotriphosphazene. Three novel aromatic polyamides such as poly(cyclotriphosphazene‐p‐phenylene amide), poly(cyclotriphosphazene‐p‐sulfuryl amide), and poly(cyclotriphosphazene‐ethyl amide) were synthesized from these diamines by direct polycondensation reaction with terephthaloyl chloride and pyridine in N‐methyl pyrrolidone, respectively. The chemical structures of the diamine monomers and three novel poly(cyclotriphosphazene‐aryl amide)s were characterized by Fourier Transform Infrared, (¹H and ³¹P) Nuclear Magnetic Resonance, and Elemental Analysis. The thermal properties of the polyamides were determined by Differential Scanning Calorimetry and Thermogravimetric Analysis (TGA). The crystallization behaviors of the polyamides were studied by Wide‐ray X‐ray diffraction, and the morphology of the pyrolysis residues were observed by Scanning Electron Microscope. The three poly(cyclotriphosphazene‐aryl amide)s with amorphous structure would exhibit an enhanced solubility in polar aprotic solvents and a superior thermal stability with initial decomposition temperature being at about 198–259°C. TGA curves of the poly(cyclotriphosphazene‐aryl amide)s exhibit mainly three thermal decomposition steps, and the poly(cyclotriphosphazene‐p‐phenylene amide) presents the highest solid residue rate 62.6% heated to 600°C. In the morphology analysis of the poly(cyclotriphosphazene‐aryl amide) solid residues, organophosphorus gelatum forms in the surface layer were observed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and property measurements of polyimides with substituted pyromellitic dianhydride for flexible printed circuits applications

Pyromellitic dianhydride‐based dianhydrides with bulky substituents, such as 1‐phenyl pyromellitic dianhydride and 1‐(4′‐trifluoromethylphenyl)pyromellitic dianhydride, were combined with bis(3‐aminophenyl)phenylphosphine oxide and 4,4′‐phenylene diamine to prepare polyimides with low coefficient of thermal expansion (～ 17 ppm/°C) and good adhesion (>100 g/mm). The polyimides were synthesized via a conventional two‐step process: preparation of poly(amic‐acid) followed by solution imidization with o‐dichlorobenzene. The molecular weights of the polyimides were controlled to 25,000 g/mol via off‐stoichiometry and the synthesized polyimides were characterized by Fourier transform infrared, nuclear magnetic resonance, differential scanning calorimetry, and thermogravimetric analysis. Their intrinsic viscosity and solubility were also measured, while adhesive property was measured via T‐peel test samples of Cu/polyimide. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Surface properties and blood compatibility of some aliphatic/aromatic polyimide blends

Two binary polyimide (PI) blends having a common monomer, diamine and dianhydride, were prepared. The first system was composed of PIs obtained from an alicyclic and flexible dianhydride, namely 5‐(2,5‐dioxotetrahydrofurfuryl)‐3‐methyl‐3‐cyclohexene‐1,2‐dicarboxylic acid anhydride (DOCDA) and two aromatic diamines, 4,4′‐oxydianiline (ODA) and p‐phenylenediamine (PPD), respectively. In the second system, ODA was combined with DOCDA and (hexafluoroisopropyldiene)diphtalic dianhydride (6FDA). Incorporation of aliphatic and asymmetric DOCDA moieties, hexafluoropropyldiene groups and ether linkages in the molecular structure of PI blends, poly(DOCDA/PPD)/poly(DOCDA‐ODA) and poly(6FDA‐ODA)/poly(DOCDA‐ODA) influenced the surface tension parameters, surface and interfacial free energy, and the work of spreading of water, maintaining the surface hydrophobic characteristics of both systems. In addition, it has been found out that surface hydrophobicity and surface roughness are properties that can be correlated with the red blood cells and platelets compatibility. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Synthesis and characterization of novel wholly para‐oriented aromatic polyamide‐hydrazides containing sulfone‐ether linkages

Four novel wholly para‐oriented aromatic polyamide‐hydrazides containing flexibilizing sulfone‐ether linkages in their main chains have been synthesized from 4‐amino‐3‐hydroxy benzhydrazide (4A3HBH) with either 4,4′‐sulfonyldibenzoyl chloride (SDBC), 4,4′‐[sulfonylbis(1,4‐phenylene)dioxy]dibenzoyl chloride (SODBC), 4,4′‐[sulfonylbis(2,6‐dimethyl‐1,4‐phenylene)dioxy]dibenzoyl chloride (4MeSODBC), or 4,4′‐(1,4‐phenylenedioxy)dibenzoyl chloride (ODBC) via a low‐temperature solution polycondensation reaction. A polyamide‐hydrazide without the flexibilizing linkages is also investigated for comparison. It was synthesized from 4A3HBH and terephthaloyl chloride (TCl) by the same synthetic route. The intrinsic viscosities of the polymer ranged from 2.85 to 4.83 dL g^?1 in N,N‐dimethyl acetamide (DMAc) at 30°C and decreased with introducing the flexibilizing linkages into the polymer. All the polymers were soluble in DMAc, N,N‐dimethyl formamide (DMF), and N‐methyl‐2‐pyrrolidone (NMP), and their solutions could be cast into films with good mechanical strengths. Further, they exhibited a great affinity to water sorption. Their solubility and hydrophilicity increased remarkably by introducing the flexibilizing linkages. The polymers could be thermally cyclodehydrated into the corresponding poly(1,3,4‐oxadiazolyl‐benzoxazoles) approximately in the region of 295–470°C either in nitrogen or in air atmospheres. The flexibilizing linkages improve the solubility of the resulting poly(1,3,4‐oxadiazolyl‐benzoxazoles) when compared with poly(1,3,4‐oxadiazolyl‐benzoxazoles) free from these linkages. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of poly(p‐phenylene diamine) and its corrosion inhibition effect on iron in 1M HCl

Water‐soluble poly(p‐phenylene diamine) was chemically synthesized. Its corrosion inhibition performance was evaluated for iron corrosion in 1M HCl at various concentrations, and the results were compared with that of the monomer. The corrosion inhibition properties were evaluated by polarization techniques and electrochemical impedance spectroscopy. The results showed that poly(p‐phenylene diamine) was a more efficient corrosion inhibitor than the monomer and gave an 85% inhibition efficiency at a concentration of 50 ppm, whereas the monomer gave an efficiency of 73% at 5000 ppm. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Electro conductivities of well‐dispersed PMMA‐g‐MWNTs/6FDA‐based polyimide composites: Effect of chemical structure

PMMA (polymethylmethacrylate), which is miscible with hexafluoropropane dianhydride (6FDA)‐based polyimide, was grafted onto MWNTs surfaces to enhance their dispersion relative to that of pristine MWNTs. The electrical conductivity of the 6FDA‐based composite revealed percolation threshold behavior, and the 6FDA‐4,4′‐(hexafluoroisopropylidene)diamine, (6FpDA):3,5‐diaminobenzoic acid (DABA)/PMMA‐g‐MWNT composite showed a higher percolation threshold concentration and a slightly lower critical exponent compared with those of the 6FDA‐6FpDA composite. Because of the weak interaction energies between 6FDA‐6FpDA:DABA and PMMA, agglomerated domains were formed. Also, the weak interaction energies of the 6FDA‐6FpDA:DABA led to a larger reduction in the normalized transmittance compared with that seen in the 6FDA‐6FpDA composite. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Preparation of Carbon Membranes Derived from Polymer Blends in the Presence of a Thermally Labile Polymer

Abstract

Carbon membranes for gas separation were prepared from the polymer blend consisting of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) and polyvinylpyrrolidone (PVP) as the thermally stable and labile polymer, respectively. The PPO/PVP derived carbon membranes with lower PVP concentrations than 0.6 wt% showed decreased gas permeances and increased permselectivity due to decrease in the pore properties (pore volume and surface area). Meanwhile, gas permeance increased for the carbon membranes prepared with higher PVP concentrations than 0.6 wt% due to the enhanced diffusional pathways for the gas transport through carbon membranes especially in the domain of the thermally labile polymer. It is considered that the introduction of the thermally labile polymer leads to control the pore structure through the permeation results for the carbon membrane derived from the polymer blend.     

Poly(amide‐hydrazide)s–graphene composites synthesis and characterization

Poly(amide‐hydrazide)s copolymers were prepared using hydrazide derivative of phenylene diamine to react with aromatic diacid chloride. The wholly aromatic poly(amide‐hydrazide)s have better solubility in organic polar solvents, such as N ,N‐dimethylacetamide, dimethylsulfoxide, 1‐methyl‐2‐pyrollidone, and N ,N‐dimethylformamide, at room temperature, while still maintaining their high thermal stability. Graphene in the nano size was used as a filler to enhance their thermal and mechanical properties. The polymers as well as the composite were characterized by spectral and mechanical tools as well as by X‐ray analysis. POLYM. COMPOS., 38:1311–1318, 2017. © 2015 Society of Plastics Engineers     

Synthesis and characterization of poly(acrylate amic acid) and its application as negative‐tone photosensitive polyimides

The dianhydride monomer 3,3′,4,4′‐benzophenone tetracarboxylic acid dianhydride and two diamine monomers, 4,4′‐diamino‐3,3′‐biphenyldiol (HAB) and 2,4‐diaminophenol dihydrochloride (DAP), were used to synthesize a series of poly(hydroxyl amic acid). Further functionalization by grafting acrylate groups yields the corresponding poly(acrylate amic acid) that underwent a crosslinking reaction on exposure to UV‐light and was used as a negative‐tone photosensitive polyimide (PSPI). The analysis of chemical composition and molecular weight of these poly(amic acid)s determined by nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy, and gel permeation chromatography revealed that the molecular weight of the poly(hydroxyl amic acid) increased with the molar content of HAB in the feedstock, because HAB exhibited higher polymerization reactivity than DAP. Moreover, the degree of grafting acrylate groups onto poly(hydroxyl amic acid) was determined by ¹H‐NMR spectroscopy. The photoresist was formulated by adding 2‐benzyl‐2‐N,N‐dimethylamino‐1‐(4‐morpholinophenyl) butanone (IRG369) and isopropylthioxanthone as a photoinitiator, tetra(ethylene glycol) diacrylate as a crosslinker, and tribromomethyl phenyl sulfone as a photosensitizer. The PSPI precursor exhibited a photosensitivity of 200 mJ/cm² and a contrast of 1.78. A pattern with a resolution of 10 μm was observed in an optical micrograph after thermal imidization at 300°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Phosphorus‐containing poly(ester‐imide)–polydimethylsiloxane copolymers

New phosphorus‐containing poly(ester‐imide)‐polydimethylsiloxane copolymers were prepared by solution polycondensation of 1,4‐[2‐(6‐oxido‐6H‐dibenz < c,e > < 1, 2 > oxaphosphorin‐6‐yl)]naphthalene‐bis(trimellitate) dianhydride with a mixture of an aromatic diamine (1,3‐bis(4‐aminophenoxy)benzene) and α,ω‐bis(3‐aminopropyl)oligodimethylsiloxane of controlled molecular weight, in various ratios. Poly(amic acid) intermediates were converted quantitatively to the corresponding polyimide structures using a solution imidization procedure. The polymers are easily soluble in polar organic solvents, such as N‐methyl‐2‐pyrrolidone and N,N‐dimethylformamide, as well as in less polar solvents such as tetrahydrofuran. They show good thermal stability, the decomposition temperature being above 370 °C. The glass transition temperatures are in the range 165–216 °C. Solutions of the polymers in N‐methyl‐2‐pyrrolidone exhibit photoluminescence in the blue region. Copyright © 2010 Society of Chemical Industry