Synthesis and properties of amphiphilic and biodegradable poly(ε‐caprolactone‐co‐glycidol) copolymers

We have synthesized poly(ε‐caprolactone‐co‐tert‐butyl glycidyl ether) (CL‐co‐BGE) statistical copolymers using 1‐tert‐butyl‐4,4,4‐tris(dimethylamino)‐2,2‐bis [tris(dimethylamino)phophoranylidenamino]‐2Λ5,4Λ5‐catenadi(phosphazene) (t‐BuP₄) as the catalyst. The hydrolysis of the resulting polymers yields amphiphilic poly(ε‐caprolactone‐co‐glycidol) (CL‐co‐GD) copolymers. By use of the quartz crystal microbalance with dissipation (QCM‐D), we have investigated the enzymatic degradation of the copolymers. It is shown that the degradation rate increases with the content of hydrophilic (GD) units. (3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide) (MTT) assay experiments demonstrate that the CL‐co‐GD copolymers have low cytotoxicity. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 846–853     

Grafting of polyamide 6 by the anionic polymerization of ε‐caprolactam from an isocyanate bearing polystyrene backbone

The grafting of polyamide 6 (PA6) onto polystyrene (PS) can rely on the use of a copolymer of styrene (St) and 3‐isopropenyl‐α, α‐dimethylbenzene isocyanate (TMI), PS‐co‐TMI, to activate the polymerization of ε‐caprolactam (CL) in the presence of sodium ε‐caprolactam (NaCL) as an anionic catalyst. This article is aimed at answering the following key questions. First, do all the isocyanate moieties of the PS‐co‐TMI participate in the activation of the polymerization of CL? Second, what are the composition of the resulting polymer product and the structure of the resulting graft copolymer? The results show that the isocyanate moieties had all participated in the activation of the polymerization, implying that each isocyanate moiety has led to the formation of a PA6 graft. The as‐polymerized product was composed of a pure PS‐g‐PA6 graft copolymer, homo‐PA6, and unreacted CL. Moreover, when the composition of a PS‐co‐TMI/CL/NaCL system was fixed, the mass ratio between the PA6 grafts and PS backbone of the pure PS‐g‐PA6 graft copolymer was almost a constant and was almost independent of its molar mass. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4766–4776, 2008     

Aminated PCL‐based copolymers by chemical modification of poly(α‐iodo‐ε‐caprolactone‐co‐ε‐caprolactone)

A novel method is proposed to access to new poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) using poly(α‐iodo‐ε‐caprolactone‐co‐ε‐caprolactone) as polymeric substrate. First, ring‐opening (co)polymerizations of α‐iodo‐ε‐caprolactone (αIεCL) with ε‐caprolactone (εCL) are performed using tin 2‐ethylhexanoate (Sn(Oct)₂) as catalyst. (Co)polymers are fully characterized by ¹H NMR, ¹³C NMR, FTIR, SEC, DSC, and TGA. Then, these iodinated polyesters are used as polymeric substrates to access to poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) by two different strategies. The first one is the reaction of poly(αIεCL‐co‐εCL) with ammonia, the second one is the reduction of poly(αN₃εCL‐co‐εCL) by hydrogenolysis. This poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) (F_αNH2εCL < 0.1) opens the way to new cationic and water‐soluble PCL‐based degradable polyesters. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6104–6115, 2009     

Anionic polymerization of cyclic ester and amide in miniemulsion: Synthesis and characterization of poly(ε‐caprolactone) and poly(ε‐caprolactone‐co‐ε‐caprolactam) nanoparticles

For the first time, poly(ε‐caprolactone) and poly(ε‐caprolactone‐co‐ε‐caprolactam) nanoparticles were successfully obtained by anionic polymerization of ε‐caprolactone and anionic copolymerization of ε‐caprolactone with ε‐caprolactam, respectively, in heterophase by the miniemulsion technique. After polymerization the resulting dispersions are stable for hours in case of the pure polyester and days for the copolymer. The syntheses were carried out with different continuous phases, amounts of surfactant, initiator, and monomers. The influence of the reaction parameters on the molecular weight of the polymers and on colloidal characteristics like size and morphology of the nanoparticles were studied by dynamic light scattering, gel permeation chromatography, differential scanning calorimetry, nuclear magnetic resonance, and Fourier transform infrared spectroscopy. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Precision synthesis of microstructures in star‐shaped copolymers of ϵ‐caprolactone,L‐lactide,and 1,5‐dioxepan‐2‐one

Star‐shaped homo‐ and copolymers were synthesized in a controlled fashion using two different initiating systems. Homopolymers of ε‐caprolactone, L ‐lactide, and 1,5‐dioxepan‐2‐one were firstly polymerized using (I) a spirocyclic tin initiator and (II) stannous octoate (cocatalyst) together with pentaerythritol ethoxylate 15/4 EO/OH (coinitiator), to give polymers with identical core moieties. Our gained understanding of the versatile and controllable initiator systems kinetics, the transesterification reactions occurring, and the role which the reaction conditions play on the material outcome, made it possible to tailor the copolymer microstructure. Two strategies were used to successfully synthesize copolymers of different microstructures with the two initiator systems, i.e., a more multiblock‐ or a block‐structure. The correct choice of the monomer addition order enabled two distinct blocks to be created for the copolymers of poly(DXO‐co‐LLA) and poly(CL‐co‐LLA). In the case of poly(CL‐co‐DXO), multiblock copolymers were created using both systems whereas longer blocks were created with the spirocyclic tin initiator. © 2008 Wiley Periodicals, Inc. JPolym Sci Part A: Polym Chem 46: 1249–1264, 2008     

Complex,degradable polyester materials via ketoxime ether‐based functionalization: Amphiphilic,multifunctional graft copolymers and their resulting solution‐state aggregates

Degradable, amphiphilic graft copolymers of poly(ε‐caprolactone)‐graft‐poly(ethylene oxide), PCL‐g‐PEO, were synthesized via a grafting onto strategy taking advantage of the ketones presented along the backbone of the statistical copolymer poly(ε‐caprolactone)‐co‐(2‐oxepane‐1,5‐dione), (PCL‐co‐OPD). Through the formation of stable ketoxime ether linkages, 3 kDa PEO grafts and p‐methoxybenzyl side chains were incorporated onto the polyester backbone with a high degree of fidelity and efficiency, as verified by NMR spectroscopies and GPC analysis (90% grafting efficiency in some cases). The resulting block graft copolymers displayed significant thermal differences, specifically a depression in the observed melting transition temperature, T_m, in comparison with the parent PCL and PEO polymers. These amphiphilic block graft copolymers undergo self‐assembly in aqueous solution with the P(CL‐co‐OPD‐co‐(OPD‐g‐PEO)) polymer forming spherical micelles and a P(CL‐co‐OPD‐co‐(OPD‐g‐PEO)‐co‐(OPD‐g‐pMeOBn)) forming cylindrical or rod‐like micelles, as observed by transmission electron microscopy and atomic force microscopy. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3553–3563, 2010     

Deformation behavior of electrospun poly(L‐lactide‐co‐ε‐caprolactone) nonwoven membranes under uniaxial tensile loading

Biodegradable poly(L ‐lactide‐co‐ε‐caprolactone) copolymers with different L ‐lactide (LLA)/ε‐caprolactone (CL) ratios of 75/25 and 50/50 were electrospun into fine fibers. The deformation behavior of the electrospun membranes with randomly oriented structures was evaluated under uniaxial tensile loading. The electrospun membrane with a higher LLA content showed a significantly higher tensile modulus but a similar maximum stress and a lower ultimate strain in comparison with the membrane with a lower LLA content. The beaded fibers that formed in the membranes caused lower tensile properties. X‐ray diffraction and differential scanning calorimetry results suggested that the electrospun fine fibers developed highly oriented structures in CL‐unit sequences during the electrospinning process even though the concentration was only 25 wt %. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3205–3212, 2005     

Preparation of novel poly(ethylene oxide‐co‐glycidol)‐graft‐poly(ε‐caprolactone) copolymers and inclusion complexation of the grafted chains with α‐cyclodextrin

A well‐defined comblike copolymer of poly(ethylene oxide‐co‐glycidol) [(poly(EO‐co‐Gly)] as the main chain and poly(ε‐caprolactone) (PCL) as the side chain was successfully prepared by the combination of anionic polymerization and ring‐opening polymerization. The glycidol was protected by ethyl vinyl ether to form 2,3‐epoxypropyl‐1‐ethoxyethyl ether (EPEE) first, and then ethylene oxide was copolymerized with EPEE by an anionic mechanism. The EPEE segments of the copolymer were deprotected by formic acid, and the glycidol segments of the copolymers were recovered after saponification. Poly(EO‐co‐Gly) with multihydroxyls was used further to initiate the ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate. When the grafted copolymer was mixed with α‐cyclodextrin, crystalline inclusion complexes (ICs) were formed, and the intermediate and final products, poly(ethylene oxide‐co‐glycidol)‐graft‐poly(ε‐caprolactone) and ICs, were characterized with gel permeation chromatography, NMR, differential scanning calorimetry, X‐ray diffraction, and thermogravimetric analysis in detail. The obtained ICs had a channel‐type crystalline structure, and the ratio of ε‐caprolactone units to α‐cyclodextrin for the ICs was higher than 1:1. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3684–3691, 2006     

Complex phase behavior and state of miscibility in Poly(ethylene glycol)/Poly(l‐lactide‐co‐ε‐caprolactone) Blends

A miscibility and phase behavior study was conducted on poly(ethylene glycol) (PEG)/poly(l ‐lactide‐ε‐caprolactone) (PLA‐co‐CL) blends. A single glass transition evolution was determined by differential scanning calorimetry initially suggesting a miscible system; however, the unusual T_g bias and subsequent morphological study conducted by polarized light optical microscopy (PLOM) and atomic force microscopy (AFM) evidenced a phase separated system for the whole range of blend compositions. PEG spherulites were found in all blends except for the PEG/PLA‐co‐CL 20/80 composition, with no interference of the comonomer in the melting point of PEG (T_m = 64 °C) and only a small one in crystallinity fraction (X_c = 80% vs. 70%). However, a clear continuous decrease in PEG spherulites growth rate (G) with increasing PLA‐co‐CL content was determined in the blends isothermally crystallized at 37 °C, G being 37 µm/min for the neat PEG and 12 µm/min for the 20 wt % PLA‐co‐CL blend. The kinetics interference in crystal growth rate of PEG suggests a diluting effect of the PLA‐co‐CL in the blends; further, PLOM and AFM provided unequivocal evidence of the interfering effect of PLA‐co‐CL on PEG crystal morphology, demonstrating imperfect crystallization in blends with interfibrillar location of the diluting amorphous component. Significantly, AFM images provided also evidence of amorphous phase separation between PEG and PLA‐co‐CL. A true T_g vs. composition diagram is proposed on the basis of the AFM analysis for phase separated PEG/PLA‐co‐CL blends revealing the existence of a second PLA‐co‐CL rich phase. According to the partial miscibility established by AFM analysis, PEG and PLA‐co‐CL rich phases, depending on blend composition, contain respectively an amount of the minority component leading to a system presenting, for every composition, two T_g's that are different of those of pure components. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014 , 52, 111–121     

Facile synthesis of triple‐stimuli (photo/pH/thermo) responsive copolymers of 2‐diazo‐1,2‐naphthoquinone‐mediated poly(N‐isopropylacrylamide‐co‐N‐hydroxymethylacrylamide)

A series of poly(N‐isopropylacrylamide‐co‐N‐hydroxymethylacrylamide) P(NIPAM‐co‐NHMA) copolymers were firstly synthesized via free radical polymerization. Then, the hydrophobic, photosensitive 2‐diazo‐1,2‐naphthoquinone (DNQ) molecules were partially and randomly grafted onto P(NIPAM‐co‐NHMA) backbone through esterification to obtain a triple‐stimuli (photo/pH/thermo) responsive copolymers of P(NIPAM‐co‐NHMA‐co‐DNQMA). UV‐vis spectra showed that the lower critical solution temperature (LCST) of P(NIPAM‐co‐NHMA) ascended with increasing hydrophilic comonomer NHMA molar fraction and can be tailored by pH variation as well. The LCST of the P(NIPAM‐co‐NHMA) went down firstly after DNQ modification and subsequently shifted to higher value after UV irradiation. Meanwhile, the phase transition profile of P(NIPAM‐co‐NHMA‐co‐DNQMA) could be triggered by pH and UV light as expected. Thus, a triple‐stimuli responsive copolymer whose solution properties could be, respectively, modulated by temperature, light, and pH, has been achieved. These stimuli‐responsive properties should be very important for controlled release delivery system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2763–2773, 2009     

Microstructure of metallocene isotactic propylene‐co‐1‐pentene‐co‐1‐hexene terpolymers

This study aims at characterizing in depth the microstructure of propylene‐co‐1‐pentene‐co‐1‐hexene terpolymers, which have been recently reported to develop the isotactic polypropylene δ trigonal polymorph when the total comonomer content is high enough. Such a specific crystalline form had been only reported so far in the analogous copolymers containing either 1‐pentene or 1‐hexene. A comparative ¹³C NMR study in solution of the aforementioned terpolymers and copolymers allows asserting the random insertion of both comonomers during chain growth under the polymerization conditions used. The reaction parameters, mainly catalyst and temperature, have been chosen for the purpose of assuring relatively high molar mass polymers. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2537–2547     

Chemical synthesis and characterization of poly(aniline‐co‐ethyl 3‐aminobenzoate) copolymers

Copolymers of aniline and ethyl 3‐aminobenzoate (3EAB) were synthesized by chemical polymerization in several mole ratios of aniline to functionalized aniline, and their physicochemical properties were compared to those of poly(aniline‐co‐3‐aminobenzoic acid) (3ABAPANI) copolymers. The copolymers were characterized with UV–vis, FTIR, Raman, SEM, EPR, and solid‐state NMR spectroscopy, elemental analysis, and conductivity measurements. The influence of the carboxylic acid and ester group ring substituents on the copolymers was investigated. The spectroscopic studies confirmed incorporation of 3ABA or 3EAB units in the copolymers and hence the presence of C?O group in the copolymer chains. The conductivity and EPR signals both decreased with increasing 3EAB content of the copolymers emeraldine salt (ES) form. The conductivity of the ES form of 3ABAPANI was found to be high (1.4 × 10^?1 S cm^?1) compared with the conductivity (10^?2–10^?3 S cm^?1) of 3EABPANI (ES) copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1339–1347, 2010     

Synthesis of 4μ‐PS2PEO2, 4μ‐PS2PCL2, 4μ‐PI2PEO2, and 4μ‐PI2PCL2 star‐shaped copolymers by the combination of glaser coupling with living anionic polymerization and ring‐opening polymerization

4μ‐A₂B₂ star‐shaped copolymers contained polystyrene (PS), poly(isoprene) (PI), poly(ethylene oxide) (PEO) or poly(ε‐caprolactone) (PCL) arms were synthesized by a combination of Glaser coupling with living anionic polymerization (LAP) and ring‐opening polymerization (ROP). Firstly, the functionalized PS or PI with an alkyne group and a protected hydroxyl group at the same end were synthesized by LAP and then modified by propargyl bromide. Subsequently, the macro‐initiator PS or PI with two active hydroxyl groups at the junction point were synthesized by Glaser coupling in the presence of pyridine/CuBr/N,N,N ′,N ″,N ″‐penta‐methyl diethylenetri‐amine (PMDETA) system and followed by hydrolysis of protected hydroxyl groups. Finally, the ROP of EO and ε‐CL monomers was carried out using diphenylmethyl potassium (DPMK) and tin(II)‐bis(2‐ethylhexanoate) (Sn(Oct)₂) as catalyst for target star‐shaped copolymers, respectively. These copolymers and their intermediates were well characterized by SEC, ¹H NMR, MALDI‐TOF mass spectra and FT‐IR in details. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Biobased poly(2,5‐furandimethylene succinate‐co‐butylene succinate) crosslinked by reversible Diels–Alder reaction

We synthesized biobased poly(2,5‐furandimethylene succinate‐co‐butylene succinate) [P(FS‐co‐BS)] copolymers by polycondensation of 2,5‐bis(hydroxymethyl)furan, 1,4‐butanediol, and succinic acid. These copolymers could be crosslinked to form network polymers by means of a reversible Diels–Alder reaction with bis‐maleimide. The thermal properties, mechanical properties, and healing abilities of the P(FS‐co‐BS)s and the network polymers were investigated. The mechanical properties of the network polymers depended on the comonomer composition of the P(FS‐co‐BS)s and the maleimide/furan ratio in the network polymers. Some of the copolymers exhibited healing ability at room temperature, and their healing efficiency was enhanced by solvent or heat. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 216–222     

Synthesis and dielectric properties of photoreactive polystyrene containing [1‐(3‐isopropenyl‐phenyl)‐1‐methyl‐ethyl]‐carbamate in the side chain

Novel polystyrene derivatives comprising [1‐(3‐isopropenyl‐phenyl)‐1‐methyl‐ethyl]‐carbamate in the side chain were synthesized as photoreactive copolymers. Poly(4‐vinylphenol) was made to react with 1‐(1‐isocyanato‐1‐methyl‐ethyl)‐3‐isopropenyl‐benzene (m‐TMI) and the unreacted hydroxyl groups were protected with acetyl chloride. The copolymers are highly sensitive to the radical photoinitiators that can be activated by irradiation of UV light (λ = 300–365 nm). FTIR spectroscopy was employed to monitor the structural changes in the copolymers exposed to UV irradiation. The dielectric properties of the copolymers were investigated by measuring the capacitance and calculating the permittivity as a function of frequency, along with the I–V characteristics. Their properties were compared with those of thermally crosslinkable poly(4‐vinylphenol) blended with poly(melamine‐co‐formaldehyde), which is frequently used as a dielectric layer in organic field‐effect transistors (OFETs). No significant dielectric dispersion was observed in the frequency range of 1 kHz–1 MHz. The dielectric constant was determined to be in the range of 4.2–6.0, which offers a potential for the application of these copolymers to OFET gate insulators. These soluble dielectrics exhibit good film uniformity and can also be patterned using a standard photolithographic technique. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1710–1718, 2008     

Synthesis of unsaturation containing P(VDF‐co‐TrFE‐co‐CTFE) from P(VDF‐co‐CTFE) in one‐pot catalyzed with Cu(0)‐based single electron transfer living radical polymerization system

Poly(vinylidene fluoride‐co‐trifluoroethylene‐co‐chlorotrifluoroethylene) (P(VDF‐co‐TrFE‐co‐CTFE)) with internal double bond has been reported with high dielectric constant and energy density at room temperature, which is expected to serve as a promising dielectric film in high pulse discharge capacitors. An environmentally friendly one‐pot route, including the controllable hydrogenation via Cu(0) mediated single electron transfer radical chain transfer reaction (SET‐CTR) and dehydrochlorination catalyzed with N‐containing reagent, is successfully developed to synthesize P(VDF‐co‐TrFE‐co‐CTFE) containing unsaturation. The resultant polymer was carefully characterized with ¹H NMR, ¹⁹F NMR, and FTIR. The composition of the resultant copolymer is strongly influenced by reaction conditions, including the reaction temperature, catalyst concentration, the types of ligands and solvents. The kinetics data of the chain transfer and elimination reaction demonstrate their well‐controlled feature of the strategy. By shifting the equilibrium between the CTR and elimination reactions dominated by N‐compounds serving as ligands in SET‐CTR and catalyst in the dehydrochlorination of P(VDF‐co‐CTFE), P(VDF‐co‐TrFE‐co‐CTFE) with tunable TrFE and double‐bond content could be synthesized in this one‐pot route. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3429–3440     

Methylated and pegylated PLA–PCL–PLA block copolymers via the chemical modification of di‐hydroxy PCL combined with the ring opening polymerization of lactide

Methylated and pegylated poly(lactide)‐block‐poly(ε‐caprolactone)‐block‐poly(lactide) copolymers, PLA–P(CL‐co‐CLCH₃)–PLA and PLA–P(CL‐co‐CLPEG)–PLA, were prepared in three steps: combining the formation of carbanion‐bearing dihydroxylated‐PCL, the coupling of iodomethane or bromoacetylated α‐hydroxyl‐ω‐methoxy‐poly(ethylene glycol) onto the carbanionic PCL, and finally the ring opening polymerization of DL ‐lactide initiated by the preformed grafted diOH‐PCL copolymers. The resulting block copolymers exhibited lower crystallinity, melting temperature, and hydrophobicity with respect to the original PCL. Degradation of the grafted copolymers was investigated in the presence of Pseudomonas cepacia lipase and compared with that of the triblock copolymer precursor. It is shown that the presence of the grafted substituents affected the enzymatic degradation of PCL segments. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4196–4205, 2005     

Mechanistic study of ring‐opening copolymerization of ɛ‐caprolactam with epoxide: Development of novel thermosetting epoxy resin system

We investigated the mechanism of the ring‐opening copolymerization of ?‐caprolactam (?‐CL) with glycidyl phenyl ether (GPE) to afford poly(?‐CL‐co‐GPE) as a model reaction of the thermal curing of certain epoxy resins with ?‐CL. The reaction of ?‐CL and GPE proceeded efficiently in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) at 170^°C for 2 h. The monomer reactivities r₁ of ?‐CL and r₂ of GPE calculated according to the Fineman‐Ross method and the Kelen‐Tüdös method were 0.58 and 5.52, respectively. These values indicate that poly(?‐CL‐co‐GPE) has a pseudo‐block gradient copolymer. Based on these results, we examined the thermal curing reactions of certain epoxy resins with ?‐CL. The corresponding novel cured products were obtained quantitatively, and each of them showed a high glass transition temperature and high thermal stability, presumably due at least in part to a pseudo‐block gradient primary structure resembling that of poly(?‐CL‐co‐GPE). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2220–2228     

Two‐sided comb poly(amic ester)–poly(propylene oxide) graft copolymers as porous polyimide precursors

New step‐growth graft block copolymers were synthesized. These two‐sided comb copolymers consisted of a poly(amic ester) (PAE) backbone and pendant poly(propylene oxide) (PPO) grafts. The copolymers were made via a macromonomer approach, in which the 4,6‐bischlorocarbonyl isophthalic acid bis[poly(propylene oxide)] ester macromonomer was synthesized through the reaction of hydroxyl‐terminated PPO oligomers with pyromellitic dianhydride and oxalyl chloride. This macromonomer was subsequently used in step‐growth polymerization with comonomers 4,6‐bischlorocarbonyl isophthalic acid diethyl ester, 2,5‐bischlorocarbonyl terephthalic acid diethyl ester, and 2,2‐bis[4‐ (4‐aminophenoxy)phenyl] hexafluoropropane, and this yielded PPO‐co‐PAE graft copolymers. Accordingly, we report the synthesis and characterization of the PPO oligomer, the PPO macromonomer, and their corresponding PPO‐co‐PAE graft copolymers. Graft copolymers with PPO concentrations of 3–26 wt % were synthesized. These polymers were thermally cured to produce polyimide/PPO composites. The thermolysis of these polyimide/PPO composites yielded porous polyimide films with porosities ranging of 4–22.5%. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2266–2275, 2005     

Donor–acceptor‐based poly(toluidine‐co‐chloroaniline)s: Synthesis and characterization

A series of poly(o‐/m‐toluidine‐co‐o‐/m‐chloroaniline) copolymers of different compositions were synthesized by an emulsion method with ammonium persulfate as the oxidant. The conductivity of the copolymers was two to five orders of magnitude higher than that of the homopolymers poly(o‐toluidine) and poly(m‐chloroaniline). Among the copolymers, the copolymer of o‐toluidine and m‐chloroaniline exhibited a maximum conductivity of 0.14 S cm^?1. The conductivity of these copolymers was also higher than that of poly(aniline‐co‐chloroaniline). The properties of the copolymers were greatly influenced by the positions of the substituents and the concentrations of the individual monomers in the feed. All the copolymers were completely soluble in polar solvents such as dimethyl sulfoxide and showed higher heat stability as the chloroaniline concentration increased. These effects could be interpreted in terms of extensive hydrogen bonding and interchain linking and, therefore, higher electron delocalization in these copolymers due to the presence of electron‐rich toluidine rings adjacent to electron‐deficient chloroaniline. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1579–1587, 2005