Synthesis and Characterization of Poly(allyl methacrylate) Obtained by Free Radical Initiator

Allyl methacrylate was polymerized in CCl₄ solution by α,α′‐azoisobutyronitrile at 50, 60, and 70°C. The kinetic curves were auto‐accelarated types at 60 and 70°C, but almost linear at 50°C. Arrhenius activation energy was 77.5 kJ/mol. The polymer was insoluble in common organic solvents. It was characterized by FT‐IR, NMR, DSC, TGA and XPS methods. About 98–99% of allyl side groups were remained as pendant even after completion of the polymerization. The spectroscopic and thermal results showed that polymerization is not a cyclopolymerization type, but may have end group cyclization. The high molecular weight is the main cause of a polymer being insoluble even in the early stage of the polymerization. Molecular weight of 1.1×10⁶ for a soluble polymer fraction was measured by light scattering method. The Tg of polymer was 94°C, and after curing at 150–200°C, increased to 211°C. The thermal pyrolysis of polymer at about 350°C gave an anhydride by linkage type degradation, and side group cyclization. The XPS analysis showed the presence of radical fragments of AIBN (initiator) and CCl₄ (solvent) associated with oligomers.     

High‐performance aromatic thermosetting resins with hydroxyl and ethynyl groups

A novel hydroxyl‐ethynyl‐arene (HEA) resin was synthesized via Aldol condensation and Sonogashira reaction. The structure of the obtained resin was confirmed by the techniques of mass spectroscopy (MS), gel permeation chromatography (GPC), proton nuclear magnetic resonance spectroscopy (¹H‐NMR), Fourier transform infrared spectroscopy, (FT‐IR) and elemental analysis (EA). Differential scanning calorimetry (DSC) results showed an exotherm at the temperature range of 187°C–245°C, attributable to crosslinking reaction of the acetylene groups. After thermal cure, the obtained cured resin possessed excellent thermal stability. Thermal gravimetric analysis (TGA) in nitrogen showed the Td₅ (temperature of 5% weight loss) was about 400°C, and the char yield in nitrogen was about 78% at 900°C. The laminate composite of HEA resin was prepared and its mechanical and thermal properties were determined. The usefulness of the HEA resin as matrix for ablative composite was evaluated. Copyright © 2010 John Wiley & Sons, Ltd.     

Solid‐state thermal stability and degradation of a family of poly(N‐isopropylacrylamide‐co‐hydroxymethylacrylamide) copolymers

There is widespread interest in responsive polymers that show cloud point behavior, but little attention is paid to their solid state thermal properties. To manufacture products based on such polymers, it may be necessary to subject them to high temperatures; hence, it is important to investigate their thermal behavior. In this study, we characterized a family of poly(N‐isopropylacrylamide‐co‐hydroxymethylacrylamide) copolymers. Although poly(N‐isopropylacrylamide) shows very high thermal stability (up to 360 °C), introduction of hydroxy side chains leads to a significant reduction in stability and new degradation processes become apparent. Thermogravimetric analysis and fourier transform infrared spectroscopy (FT‐IR) indicate that the first degradation process involves a chemical dehydration step (110–240 °C), supported by the nonreversing heat flow response in modulated temperature differential scanning calorimetry. Water loss scales with the fraction of hydroxy monomer in the copolymer. Glass transition temperatures (T_g) are higher than the temperatures causing dehydration; hence, these values relate to newly‐formed copolymer structures produced by controlled heating under nitrogen. Fourier transform‐Raman (FT‐Raman) spectra suggest that this transition involves imine formation. The T_g increases as the fraction of hydroxy groups in the original copolymer increases. Further heating leads to degradation and mass loss, and more complex changes in the FT‐IR spectra, consistent with formation of unsaturated species. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Novel Photosensitive Polymer: Synthesis,Characterization and Thermal Properties of Polymer having Pendant Photocrosslinkable Group

New methacrylic monomer having free radical polymerizable methacryloyl group and photocrosslinkable functional group was synthesized by reacting hydroxyl chalcone with methacryloyl chloride. The monomer was homopolymerized in methyl ethyl ketone solvent using benzoyl peroxide as an initiator at 70°C. The prepared homopolymer was characterized by UV, FT‐IR, ¹H‐NMR and ¹³C‐NMR spectra. The molecular weights (M_w and M_n) were estimated by gel permeation chromatography. The thermal stability of the polymer was measured by thermogravimetric analysis. The glass transition temperature of the polymer was determined by differential scanning calorimetry. The photocrosslinking property of the polymer was also studied.     

Synthesis of hyperbranched polymethylvinylborosiloxanes and modification of addition‐curable silicone with improved thermal stability

This paper reports a non‐catalyzed environmentally friendly method of synthesizing hyperbranched polymethylvinylborosiloxanes (PMVBSs) and their use to improve the thermal stability of normal addition‐curable silicones (ACSs). PMVBSs were synthesized by the direct polycondensation of dimethoxymethylvinylsilane with boric acid at 80–130°C in 1,4‐dioxane or diglyme. They were characterized by gel permeation chromatography; FT‐IR; ¹H, ¹³C, ²⁹Si and ¹¹B NMR; and TGA. PMVBSs were composed of Si―O―Si and Si―O―B bridges with some unreacted B―OH groups remaining, and had a ceramic yield up to 65.97% at 900°C. PMVBS‐modified ACSs (PBS‐ACSs) were prepared by curing the PMVBSs with hydrogen‐containing silicone oil under Karstedt (platinum divinyltetramethyldisiloxane) catalysis. Thermal stability of PBS‐ACSs was characterized by TGA in N₂ or air, and ceramic yields as high as 76.7% were obtained. Gas decomposition during the ceramization of PBS‐ACSs was examined by TG/mass spectroscopy. The SiBOC ceramics formed were characterized by FT‐IR, Raman, ²⁹Si and ¹¹B magic angle spinning NMR and elemental analysis. This method provides a valuable way to improve the thermal stability of ACSs. Copyright © 2013 John Wiley & Sons, Ltd.     

Thermal behavior of poly(vinylbenzyl chloride)‐grafted poly(ethylene‐co‐tetrafluoroethylene) films

The effect of the degree of grafting (DOG) on the thermal behavior of poly(vinylbenzyl chloride)‐grafted poly(ethylene‐co‐tetrafluoroethylene) (ETFE‐g‐PVBC) films was investigated by differential scanning calorimetry (DSC), X‐ray diffraction (XRD), dynamic mechanical analysis ( DMA), FT‐IR, and thermogravimetric analysis (TGA) instruments. Several ETFE‐g‐PVBC films with various degrees of grafting, including 10, 24, 41, 60, and 94%, were prepared using a radiation grafting technique. The DSC and XRD results of the ETFE‐g‐PVBC films revealed that the crystallinity of the films decreased as the DOG increased. The DMA and FT‐IR results of the films indicated that a crosslinking reaction occurred at temperatures above 250 °C. In the thermal properties of the grafted films, an increase in the DOG led to an increase in the decomposition temperature. The activation energy (E_a) of the thermal decomposition was calculated using Kissinger's equation from TGA results. The E_a value of the PVBC graft chain was found to increase as the DOG increased, indicating that the crosslinking reaction of ETFE‐g‐PVBC films increased with an increase in the DOG during the thermal degradation process. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 517–525     

Rigid‐rod polyamides and polyimides prepared from 4,3″‐diamino‐2′,6′‐di(2‐naphthyl)‐p‐terphenyl and 2′,6′,3‴,5‴‐tetra(2‐naphthyl)‐4,4″‐diamino‐p‐quinquephenyl

A series of rigid‐rod polyamides and polyimides containing p‐terphenyl or p‐quinquephenyl moieties in backbone as well as naphthyl pendent groups were synthesized from two new aromatic diamines. The polymers were characterized by inherent viscosity, elemental analysis, FT‐IR, ¹H‐NMR, ¹³C‐NMR, X‐ray, differential scanning calorimetry (DSC), thermomechanical analysis (TMA), thermal gravimetric analysis (TGA), isothermal gravimetric analysis, and moisture absorption. All polymers were amorphous and displayed T_g values at 304–337°C. Polyamides dissolved upon heating in polar aprotic solvents containing LiCl as well as CCl₃COOH, whereas polyimides were partially soluble in these solvents. No weight loss was observed up to 377–422°C in N₂ and 355–397°C in air. The anaerobic char yields were 57–69% at 800°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 15–24, 1999     

Homo‐ and Copolymerization of Phenacyl Methacrylate via the Atom Transfer Radical Polymerization Method

The homo‐ and copolymers via atom transfer radical (co)polymerization (ATRP) of phenacyl methacrylate (PAMA) with methyl methacrylate (MMA) and t‐butyl methacrylate (t‐BMA) was performed in bulk at 90°C in the presence of ethyl 2‐bromoacetate, cuprous(I)bromide (CuBr), and 2,2′‐bipyridine. The polymerization of PAMA was carried out at 70, 80, and 100°C. Also, free‐radical polymerization of PAMA was carried out at 60°C. Characterization using FT‐IR and ¹³C‐NMR techniques confirmed the formation of a five‐membered lactone ring through ATRP. The in situ addition of methylmethacrylate to a macroinitiator of poly(phenacyl methacrylate) [Mn=2800, Mw/Mn=1.16] afforded an AB‐type block copolymer [Mn=13600, Mw/Mn=1.46]. When PAMA units increased in the living copolymer system, the Mn values and the polydispersities were decreased (1.1<Mw/Mn<1.79). The monomer reactivity ratios were computed using Kelen‐Tüdös (K‐T), Fineman‐Ross (F‐R) and Tidwell‐Mortimer (T‐M) methods and were found to be r₁= 1.17; r₂= 0.76; r₁=1.16; r₂=0.75 and r₁=1.18; r₂=0.76, respectively (r₁=is monomer reactivity ratio of PAMA). The initial decomposition temperatures of the resulting copolymers were measured by TGA. Blends of poly(PAMA) and poly(MMA) obtained via the ATRP method have been characterized by differential thermal and thermogravimetric analyses.     

Effect of the Brush Structure on the Degradation Mechanism of Polystyrene–Clay Nanocomposites

Summary: Pyrolysis‐GC‐MS and TGA‐FT‐IR methods have been used to perform a comparative degradation study of polystyrene and a polystyrene–clay composite. An abnormally high yield of α‐methylstyrene has been detected for the composite. This and other differences in degradation products have been explained by enhanced intermolecular interaction of the grafted PS chains, forming a brush structure. A conceptual model of the process has been suggested.

GC pyrograms of virgin PS (A) and PS–clay composite (B) pyrolyzed at 500 °C (1: styrene; 2: 2,4‐diphenylbut‐1‐ene; 2′: dimer derivatives; 3: 2,4,6‐triphenylhex‐1‐ene; 3′: trimer derivatives; 4: α‐methylstyrene).     

Novel Copolymers of Vinyl Acetate and Alkyl Ring‐Substituted 2‐Phenyl‐1,1‐dicyanoethylenes

Electrophilic trisubstituted ethylene monomers, alkyl ring‐substituted 2‐phenyl‐1,1‐dicyanoethylenes, RC₆H₄CH?C(CN)₂ (where R is 2‐methyl, 3‐methyl,4‐methyl, 4‐ethyl, 4‐isopropyl, 4‐butyl, and 4‐t‐butyl), were synthesized by piperidine catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and malononitrile, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and vinyl acetate were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C‐NMR, GPC, DSC, and TGA. High T_g of the copolymers, in comparison with that of polyvinyl acetate, indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 190–700°C range.     

Preparation and properties of polycarbonate/polyhedral oligomeric silsesquioxanes (POSS) hybrid composites

Octaphenylsilsesquioxane (PH‐POSS) and octa(γ‐methacryloxypropyl)silsesquioxane (MA‐POSS) were successfully synthesized by hydrolytic condensation of phenyltrichlorosilane and γ‐methacryloxypropyltrimethoxysilane, and characterized by Fourier transform infrared (FT‐IR), ¹H and ²⁹Si nuclear magnetic resonance (NMR), and matrix‐assisted laser desorption/ionization‐time of flight (MALDI‐TOF) mass spectrum. Morphology, degradation behavior, thermal, and mechanical properties of hybrid composites were studied by transmission electron microscopy (TEM), polarized optical microscopy (POM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), surface contact angle (SCA), tensile, and impact testing. Domains of PH‐POSS and MA‐POSS dispersed in the matrix with a wide size distribution in a range of 0.1–0.5 µm, while PH‐POSS exhibited a preferential dispersion. Because of the possible homopolymerization of MA‐POSS during the melt blending, the glass transition temperature of polycarbonate (PC)/MA‐POSS composites remained nearly unchanged with respect to PC/PH‐POSS composites that showed a depression of T_g due to the plasticization effect. It is interesting to note that the incorporation of POSS retarded the degradation rates of PC composites and thus significantly improved the thermal stabilities. Si? O fractions left during POSS degradations were a key factor governing the formation of a gel network layer on the exterior surface. This layer possessed more compact structures, higher thermal stabilities, and some thermal insulation. In addition, percentage residues at 700°C (C₇₀₀) significantly increased from 10.8% to 15.8–22.1% in air. Fracture stress of two composites showed a slight improvement, and the impact strength of them decreased monotonically with the increase of POSS loading. Copyright © 2011 John Wiley & Sons, Ltd.     

Enhanced thermal properties and flame retardancy of unsaturated polyester‐based hybrid materials containing phosphorus and silicon

A phosphorus and silicon containing liquid monomer (9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐oxide–vinyltrimethoxysilane (DOPO–VTS)) was synthesized by the reaction between DOPO and VTS. DOPO–VTS and methacryloxypropyltrimethoxylsilane were introduced into unsaturated polyester resin to prepare flame retardant UPR/SiO₂ (FR‐UPR/SiO₂) hybrid materials by sol–gel method and curing process. DOPO–VTS contributes excellent flame retardancy to UPR matrix, which was confirmed by the limiting oxygen index and microscale combustion calorimeter results. The thermogravimetric analysis (TGA) results indicate that the FR‐UPR/SiO₂ hybrid materials possess higher thermal stability and residual char yields than those of pure UPR at high temperature region. The thermal degradation of materials was investigated by TGA/infrared spectrometry (TG‐IR) and real‐time infrared spectrometry (RT‐IR), providing insight into the thermal degradation mechanism. Moreover, scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS) were used to explore the morphologies and chemical components of the residual char. Copyright © 2013 John Wiley & Sons, Ltd.     

Thermal decomposition of cerium(III) perchlorate

Thermal decomposition of Ce(ClO₄)₃ ? 9H₂O and Ce(ClO₄)₃ to give cerium(IV) dioxide in the temperature range 240–460°C was studied by DSC–TGA, X-ray powder diffraction, IR and mass spectroscopy. The thermolysis of these salts was shown to proceed through the stage of formation of intermediate product supposedly cerium oxoperchlorate. The thermal decomposition of cerium(III) perchlorate hydrate at 460°C leads to formation of nanocrystalline cerium dioxide with particle size of 13 nm.     

Novel Copolymers of Styrene and Alkoxy Ring‐Substituted 2‐Phenyl‐1,1‐dicyanoethylenes

Electrophilic trisubstituted ethylene monomers, ring‐substituted 2‐phenyl‐1,1‐dicyanoethylenes, RC₆H₄CH?C(CN)₂ (where R is 2‐methoxy, 3‐methoxy, 4‐methoxy, 4‐ethoxy, 4‐propoxy, and 4‐butoxy), were synthesized by piperidine catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and malononitrile, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (AIBN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C NMR, GPC, DSC, and TGA. High T _g of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 290–450°C range.     

Novel Copolymers of Styrene and Some Ring‐Substituted 2‐Cyano‐N,N‐Dimethyl‐3‐Phenyl‐2‐Propenamides

Electrophilic trisubstituted ethylene monomers, ring‐substituted 2‐cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides, RC₆H₄CH?C(CN)CON(CH₃)₂ (where R is 3‐benzyloxy, 4‐benzyloxy, 3‐ethoxy‐4‐methoxy, 3‐bromo‐4‐methoxy, 5‐bromo‐2‐methoxy, 2‐chloro‐6‐fluoro) were synthesized by potassium hydroxide catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and N,N‐dimethyl cyanoacetamide, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator, ABCN at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C NMR, GPC, DSC, and TGA. High T_g of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 300–450°C range.     

Novel Copolymers of Styrene and Alkyl and Alkoxy Ring‐Trisubstituted Methyl 2‐Cyano‐3‐phenyl‐2‐propenoates

Electrophilic trisubstituted ethylene monomers, akyl and alkoxy ring‐trisubstituted methyl 2‐cyano‐3‐phenyl‐2‐propenoates, RC₆H₂CH[dbnd]C(CN)CO₂CH_3, (where R is 2,3‐dimethyl‐4‐methoxy, 2,5‐dimethyl‐4‐methoxy‐, 2,3,4‐trimethoxy‐, 2,4,5‐trimethoxy, 2,4,6‐trimethoxy, and 2,4‐dimethoxy‐3‐methyl), were synthesized by the piperidine catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and methyl cyanoacetate, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (AIBN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C NMR, GPC, DSC, and TGA. High T_g of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 283–306°C range.     

Novel Copolymers of Styrene and Halogen Ring‐Disubstituted 2‐Cyano‐N,N‐Dimethyl‐3‐Phenyl‐2‐Propenamides

Electrophilic trisubstituted ethylene monomers, halogen ring‐disubstituted 2‐cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides, RC₆H₃CH?C(CN)CON(CH₃)₂ (where R is 2,3‐dichloro, 2,4‐dichloro, 2,6‐dichloro, 3,4‐dichloro, 3,5‐dichloro, 2,3‐difluoro, 2,4‐difluoro, 2,6‐difluoro, 3,4‐difluoro, 3,5‐difluoro), were synthesized by potassium hydroxide catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and N,N‐dimethyl cyanoacetamide, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator, ABCN at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C NMR, GPC, DSC, and TGA. High T_g of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 300–450°C range.     

Designing of energetic miktoarm A2B2 star‐shaped polymer by means of click chemistry and ROP techniques

Novel A₂B₂‐type energetic miktoarm star‐shaped copolymers composed of two PGN arms and two PCL arms was synthesized by the combination of ring‐opening polymerization (ROP) and “click” chemistry. Initially, diazido end‐functionalized two‐arm PGN, (PGN)₂‐(N₃)₂, was synthesized by ROP of glycidyl nitrate monomers. Subsequently, (PGN)₂‐(PCL)₂ was obtained from the click reaction between diazido end‐functionalized (PGN)₂‐(N₃)₂ polymers and propargyl‐terminated poly(ε‐caprolactone) (PTPCL). This star copolymer solves problems of PCL (lake of energy) and PGN (low T_g). The Fourier‐transform infrared (FT‐IR), ¹H nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) studies revealed that (PGN)₂‐(PCL)₂ was successfully obtained. The thermal behavior of star polymer was investigated by thermogravimetric analysis (TGA) and derivative thermogravimetry. The results show that (PGN)₂‐(PCL)₂ decomposed at two stages. The first stage is seen at 212.6°C which related to degradation of –ONO₂ group and second stage attributed to degradation of PCL group which is seen at 346.1°C.     

Preparation and characterization of polyvinyl alcohol‐grafted Fe3O4 magnetic nanoparticles through glutaraldehyde

Magnetic nanoparticles (MNPs) are of great interest owing to their numerous existing and potential biomedical applications. To further explore the potential of MNPs in biomedical and other fields, we have designed and synthesized polyvinyl alcohol (PVA) polymer grafted Fe₃O₄ MNPs through glutaraldehyde (GLA) link. The success of this process has been ascertained using Fourier transform infrared (FT‐IR) analysis, thermogravimetric analysis (TGA), X‐ray diffraction (XRD) analysis and scanning electron microscopy (SEM) analysis. The FT‐IR analysis of resultant MNPs show infrared peak characteristics of PVA. TGA analysis clearly shows two major stages of thermal degradation, one corresponding to organic phase of PVA and GLA and another corresponding to Fe₃O₄ nanoparticles. XRD results and SEM images further support the FT‐IR and TGA results and confirm the presence of PVA layer surrounding Fe₃O₄ MNP surface. Under SEM examination, the magnetic cores exhibit somewhat irregular shapes varying from spherical, to oval to cubic. Copyright © 2012 John Wiley & Sons, Ltd.     

Amine–quinone polyimide: A new high‐temperature polymer and its use to protect iron against corrosion

A new diamine monomer was synthesized by the Michael addition of 4,4′‐methylene dianiline with 1,4‐benzoquinone. The monomer was condensed with 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride to give a polyamic acid that was soluble in NMP. The polyamic acid was cast onto iron and thermally imidized to yield the amine–quinone polyimide (AQPI‐2). AQPI‐2 had a thermal decomposition temperature of 540 °C (10% TGA weight loss in N₂) and a glass transition at 292 °C, values typical of polyimides. The degradation of the coating on iron after exposure to 0.1 M NaCl electrolyte was followed by electrochemical impedance spectroscopy. Under these conditions a conventional polyimide failed after 3 days exposure, while AQPI‐2 survived more than 24 days exposure. The adhesive bond between the amine–quinone polyimide and the iron surface was so strong that it could not be broken by the electrolyte. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2893–2899, 2000