Effects of solvent basicity on free radical polymerizations of N,N′‐bismaleimide‐4,4′‐diphenylmethane initiated by barbituric acid

The polymerizations of N,N′‐bismaleimide‐4,4′‐diphenylmethane (BMI) initiated by barbituric acid (BTA) carried out in a variety of solvents at 130°C were studied. The nitrogen‐containing cyclic solvents such as N‐methyl‐2‐pyrrolidinone acted as a catalyst to promote the formation of the three‐dimensional crosslinked network structure. By contrast, the polymerization in a cyclic solvent that did not contain nitrogen such as γ‐butyrolactone resulted in nil gel content. The higher the solvent basicity, the larger the amount of insoluble polymer species formed. The molar ratio of BTA to BMI also played an important role in the polymerizations. The resultant polymers, presumably having a hyper‐branched structure, exhibited much narrower molecular weight distributions than those prepared by conventional free radical polymerizations. The BMI polymerizations using BTA as the initiator could not be adequately described by conventional free radical polymerization mechanisms. A polymerization mechanism that took into account the generation of a ketone radical pair between BTA and BMI and the subsequent initiation, propagation and termination reactions was proposed. It was concluded that the nitrogen‐containing cyclic solvents were capable of participating in the ketone radical pair formation process, thereby increasing the extent of polymer crosslinking reactions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Water‐soluble copolymers of 1‐vinyl‐2‐pyrrolidone and acrylamide derivatives: synthesis,characterization, and metal binding capability studied by liquid‐phase polymer‐based retention technique

Radical copolymerizations of 1‐vinyl‐2‐pyrrolidone with acrylamide and N,N′‐dimethylacrylamide at different feed ratios were investigated. The copolymers were characterized by Fourier transform infrared spectroscopy, ¹H NMR, and ¹³C NMR spectroscopy. The copolymer composition was determined from the ¹H NMR spectra and found to be statistical. The metal complexation of poly(acrylamide‐co‐1‐vinyl‐2‐pyrrolidone) and poly(N,N′‐dimethylacrylamide‐co‐1‐vinyl‐2‐pyrrolidone) for the metal ions Cu(II), Co(II), Ni(II), Cd(II), Zn(II), Pb(II), Fe(III), and Cr(III) were investigated in an aqueous phase. The liquid‐phase polymer‐based retention method is based on the retention of inorganic ions by soluble polymers in a membrane filtration cell and subsequent separation of low‐molecular compounds from the polymer complex formed. The metal ion interaction with the hydrophilic polymers was determined as a function of the pH and the filtration factor. Poly(N,N‐dimethylacrylamide‐co‐1‐vinyl‐2‐pyrrolidone) showed a higher affinity for the metal ions than poly(acrylamide‐co‐1‐vinyl‐2‐pyrrolidone). According to the interaction pattern obtained, Cr(III) and Cu(II) formed the most stable complexes at pH 7. Pb(II) and Zn(II) were not retained. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 741–750, 1999     

Synthesis and characterization of new optically active poly(amide‐imide‐urethane) thermoplastic elastomers,derived from 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L‐leucine‐p‐aminobenzoic acid) and PEG‐MDI

A new class of optically active poly(amide‐imide‐urethane) was synthesized via two‐step reactions. In the first step, 4,4′‐methylene‐bis(4‐phenylisocyanate) (MDI) reacts with several poly(ethylene glycols) (PEGs) such as PEG‐400, PEG‐600, PEG‐2000, PEG‐4000, and PEG‐6000 to produce the soft segment parts. On the other hand, 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine‐p‐amidobenzoic acid) (2) was prepared from the reaction of 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine) diacid chloride with p‐aminobenzoic acid to produce hard segment part. The chain extension of the above soft segment with the amide‐imide 2 is the second step to give a homologue series of poly(amide‐imide‐urethanes). The resulting polymers with moderate inherent viscosity of 0.29–1.38 dL/g are optically active and thermally stable. All of the above polymers were fully characterized by IR spectroscopy, elemental analyses, and specific rotation. Some structural characterization and physical properties of this new optically active poly(amide‐imide‐urethanes) are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2288–2294, 2004     

Cast polyurethane elastomers obtained with N,N′‐ethyleneurea and 1,4‐butanediol as chain extenders

Tensile properties and dynamic mechanical thermal properties for polyurethane elastomers extended with N,N′‐ethyleneurea (EU) and 1,4‐butanediol (1,4‐BD) were investigated. Also gel permeation chromatography and extraction experiments for selected elastomers were performed. EU residues were introduced into polyurethane during prepolymer synthesis at 140°C. Such prepolymers with built‐in EU residues were extended with 1,4‐BD for different [NCO]/[OH] molar ratios. The use of EU chain extender produces in general polymers with inferior mechanical properties compared to the typical 1,4‐BD based polyurethanes, although some of the EU‐based polymers show improved strain‐stress parameters. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 728–733, 2000     

Synthesis and characterization of novel optically active poly(imide–urethane)s derived from N,N′‐(pyromellitoyl)‐bis‐(L‐leucine) diisocyanate and aromatic diols

N,N′‐(Pyromellitoyl)‐bis‐(L ‐leucine) diacid was reacted with ethyl chloroformate in the presence of triethylamine followed by reaction with activated sodium azide and gave N,N′‐(pyromellitoyl)‐bis‐(L ‐leucine) diacylazide in high yield. This diacylazide was heated in dry benzene and gave the unstable N,N′‐(pyromellitoyl)‐bis‐(L ‐leucine) diisocyanate ( 5 ) in quantitative yield. Thus, diisocyanate 5 was generated in situ and polycondensation reaction of this monomer with several aromatic diols, such as 4,4′‐dihydroxybiphenyl, 1,4‐hydroquinone, bisphenol A, phenolphthalein and 1,4‐dihydroxyanthraquinone, was performed in dry toluene under refluxing in the presence of 1,4‐diazabicyclo[2.2.2]octane (triethylenediamine) as a catalyst. The polymerization reactions proceeded within 48 h, producing a series of optically active poly(imide–urethane)s with good yield and moderate inherent viscosity in the range 0.18–0.28 dl g^?1. All of the above polymers were fully characterized by infrared spectra, elemental analyses and specific rotation. Some structural characterization and physical properties of these optically active poly(imide–urethane)s are reported Copyright © 2003 Society of Chemical Industry     

Monomers and polymers of 4‐(N,N‐diallylamino)pyridine functions

4‐(N,N‐Diallylamino)pyridine (DAAP), N,N‐diallylaminobenzene (DAAB), N,N,N′,N′‐tetrallyl‐4,4′‐diaminobenzidine (AAB), N,N,N′,N′‐tetrallyl‐4,4′‐diaminodiphenyl sulfone (AABS), and N,N,N′,N′‐tetrallyl‐4,4′‐diaminodiphenyl ether (AABE) were prepared by sodium substitution and N‐allylation. Moreover, linear polyDAAP, poly(DAAP‐co‐DAAB), and network poly(DAAP‐co‐AAB), poly(DAAP‐co‐AABS), and poly(DAAP‐co‐AABE), all being polymers containing supernucleophilic groups, were synthesized in the cyclopolymerization. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 363–367, 2000     

Synthesis and characterization of N‐ and O‐alkylated poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline]

Poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline] was synthesized in an aqueous hydrochloric acid medium with a determined feed ratio by chemical oxidative polymerization. This polymer was used as a functional conducting polymer intermediate because of its side‐group reactivity. To synthesize the alkyl‐substituted copolymer, the initial copolymer was reacted with NaH to obtain the N‐ and O‐anionic copolymer after the reaction with octadecyl bromide to prepare the octadecyl‐substituted polymer. The microstructure of the obtained polymers was characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, and X‐ray diffraction. The thermal behavior of the polymers was investigated by thermogravimetric analysis and differential scanning calorimetry. The morphology of obtained copolymers was studied by scanning electron microscopy. The cyclic voltammetry investigation showed the electroactivity of poly [aniline‐co‐N‐(2‐hydroxyethyl) aniline] and N and O‐alkylated poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline]. The conductivities of the polymers were 5 × 10^?5 S/cm for poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline] and 5 ×10^?7 S/cm for the octadecyl‐substituted copolymer. The conductivity measurements were performed with a four‐point probe method. The solubility of the initial copolymer in common organic solvents such as N‐methyl‐2‐pyrrolidone and dimethylformamide was greater than polyaniline. The alkylated copolymer was mainly soluble in nonpolar solvents such as n‐hexane and cyclohexane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparations and properties of thermosensitive terpolymers of N‐isopropylacrylamide,sodium 2‐acrylamido‐2‐methyl‐propanesuphonate,and N‐tert‐butylacrylamide

Terpolymers based on N‐isopropylacrylamide, sodium 2‐acrylamido‐2‐methyl‐propanesulfonate, and N‐tert‐butylacrylamide were synthesized by free‐radical copolymerization with 2,2′‐azobisisobutyronitrile as an initiator. The lower critical solution temperatures (LCSTs) of the linear polymer aqueous solutions were determined by the measurement of the transmittance on UV at different temperatures. The influence of the polymer concentration, polymer composition, and ionic strength on the LCSTs of the linear polymers was investigated. The LCST decreased with increases in the hydrophobic monomer N‐tert‐butylacrylamide, polymer concentration, and ionic strength. The phase transition became sharp when the polymer concentration and ionic strength increased. Meanwhile, the crosslinked hydrogels were prepared with the same recipe used for the linear terpolymers, but a crosslinker was added to the reaction system. The swelling ratios of the hydrogels at various temperatures and salt solutions were determined. The hydrogels possessed both high swelling ratios and thermosensitivity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis of soluble and thermally stable polyimides from 3,5‐diamino‐N‐(4‐(8‐quinolinoxy) phenyl) aniline and various dianhydrides

Three novel polyimides (PIs) having pendent 4‐(quinolin‐8‐yloxy) aniline group were prepared by polycondensation of a new diamine with commercially available tetracarboxylic dianhydrides, such as pyromellitic dianhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bicyclo[2.2.2]‐oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride. These PIs were characterized by FTIR, ¹H NMR, and elemental analysis; they had high yields with inherent viscosities in the range of 0.4–0.5 dl g⁻¹, and exhibited excellent solubility in many organic solvents such as N,N‐dimethyl acetamide, N,N′‐dimethyl formamide, N‐methyl pyrrolidone (NMP), dimethyl sulfoxide, and pyridine. These PIs exhibited glass transition temperatures (T_g) between 250 and 325° C. Their initial decomposition temperatures (T_i) ranged between 270 and 450°C, and 10% weight loss temperature (T₁₀) up to 500°C with 68% char yield at 600°C under nitrogen atmosphere. Transparent and hard polymer films were obtained via casting from their NMP solutions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation of thermosensitive and superabsorbent polymer hydrogels from trialkyl‐4‐vinylbenzyl phosphonium chloride‐N‐isopropylacrylamide‐N,N′‐methylenebisacrylamide copolymers and their properties

Thermosensitive and superabsorbent polymer hydrogels were synthesized by copolymerization of three kinds of tri‐n‐alkyl vinylbenzyl phosphonium chlorides (TRVB) with different lengths of alkyl chains, N‐isopropylacrylamide (NIPAAm), and N,N′‐methylenebisacrylamide (MBAAm). The water‐absorption ability and antibacterial activity of the hydrogels against Staphylococcus aureus (S. aureus) were investigated. The water content of TRVB–NIPAAm–MBAAm copolymers decreased with increasing temperature and increased with increasing phosphonium groups in the copolymers, while it decreased with increasing chain length of the alkyl groups in the phosphonium groups as well as with an increasing degree of crosslinking in the copolymers. The TRVB–NIPAAm–MBAAm copolymers with a higher TRVB content in the copolymers exhibited higher antibacterial activity against S. aureus, but decreased with increasing chain length of alkyl groups in phosphonium groups. The TRVB–NIPAAm–MBAAm copolymers exhibited the highest antibacterial activity at 30°C against S. aureus in deionized water. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 115–124, 2001     

Grafting of N,N′‐methylenebisacrylamide onto cellulose using Co(III)‐acetylacetonate complex in aqueous medium

The grafting of N,N′‐methylenebisacrylamide (N,N′‐MBA) onto cellulose is carried out using the cobaltacetylacetonate complex (Co(acac)₃) under nitrogen atmosphere at 40°C. The rate of graft copolymerization has been studied as a function of [N,N′‐MBA], [Co(acac)₃], and temperature. The activation energy of grafting is found to be 156.0 k J mol⁻¹ within the temperature range of 30–60°C. The effect of perchloric acid, methanol, and surfactants on graft yield has also been studied and results are suitably explained. The higher efficiency of the metal chelate in initiation of graft copolymerization has been assumed due to the coordination of the π electrons of the N,N′‐MBA with the metal chelate, which facilitated the formation of the radicals through homolytic cleavage of metal–oxygen bond of the cobalt acetylacetonate complex. On the basis of the results, a suitable kinetic scheme for graft copolymerization is presented and rate expression is derived. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 906–912, 2000     

Synthesis of poly‐N‐(thiazol‐2‐yl)methacrylamide: Characterization,complexation, and bioactivity

Cu(II) complexes with N‐(thiazol‐2‐yl)methacrylamide (NTM) and its polymer PNTM have been synthesized. The ligands (NTM and PNTM) and their Cu(II) complexes have been characterized by FTIR and ¹H‐NMR. EDX was performed to know the elemental composition and X‐ray powder diffractometry (XRD) analysis was applied to detect the crystallinity of the complexes. The morphology of these complexes was investigated with scanning electron microscopy (SEM) and proves that the monomer complexes have a strongly crystalline structure compared with the polymer complexes, which show that it is only weakly crystalline. These results from SEM are in agreement with results obtained from XRD. Thermal properties of the ligands and their complexes have been studied by thermogravimetric analysis and differential scanning calorimetry. The activity of the ligands and their complexes has been screened against S. aureus, E. coli, Pseudomonas, and Candida albicans. The synthesized compounds have shown good affinity as antibacterial and antifungal agents, which increased on complexation with Cu(II) ion. The results of these studies show the Cu(II) complexes to be more thermal stable as compared with NTM and PNTM. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of novel polyaspartimides derived from 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl and various diamines

A novel bismaleimide, 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl, containing noncoplanar 2,2′‐dimethylbiphenylene and flexible ether units in the polymer backbone was synthesized from 2,2′‐dimethyl‐4,4′‐bis(4‐aminophenoxy)biphenyl with maleic anhydride. The bismaleimide was reacted with 11 diamines using m‐cresol as a solvent and glacial acetic acid as a catalyst to produce novel polyaspartimides. Polymers were identified by elemental analysis and infrared spectroscopy, and characterized by solubility test, X‐ray diffraction, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis). The inherent viscosities of the polymers varied from 0.22 to 0.48 dL g⁻¹ in concentration of 1.0 g dL⁻¹ of N,N‐dimethylformamide. All polymers are soluble in N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethylsulfoxide, pyridine, m‐cresol, and tetrahydrofuran. The polymers, except PASI‐4, had moderate glass transition temperature in the range of 188°–226°C and good thermo‐oxidative stability, losing 10% mass in the range of 375°–426°C in air and 357°–415°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 279–286, 1999     

Synthesis,structural and spectral properties of an ionic polyacetylene: Poly[N‐(5‐nitro‐2‐furanmethylene)‐2‐ethynylpyridinium bromide]

A new ionic polyacetylene was prepared by the activation polymerization of 2‐ethynylpyridine with 2‐(bromomethyl)‐5‐nitrofuran in high yield without any additional initiator or catalyst. This polymerization proceeded well in a homogeneous manner to give a high yield of the polymer (92%). The activated acetylenic triple bond of N‐(5‐nitro‐2‐furanmethylene)‐2‐ethynylpyridinium bromide, formed in the first quaternerization process, was found to be susceptible to linear polymerization. This polymer was completely soluble in such polar organic solvents as dimethylformamide, dimethyl sulfoxide, and N,N‐dimethylacetamide. The inherent viscosities of the resulting polymers were in the range 0.12–0.19 dL/g, and X‐ray diffraction analysis data indicated that this polymer was mostly amorphous. The polymer structure was characterized by various instrumental methods to have a polyacetylene backbone structure with the designed substituent. The photoluminescence peak was observed at 593 nm; this corresponded to a photon energy of 2.09 eV. The polymer exhibited irreversible electrochemical behaviors between the doping and undoping peaks. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and magnetic properties of novel poly(N‐2‐thiazolyl(meth)acrylamide)‐Fe(II) complexes

N‐2‐thiazolyl(meth)acrylamides were polymerized by a radical route to obtain polymers in good yields. The polymers, with a pendent heterocyclic group, are soluble in common organic solvents, which allow the corresponding metal complexes with higher loads to be prepared easily. FTIR, ¹H NMR, and energy‐dispersive X‐Ray spectroscopy (EDX) were applied to characterize these materials. The magnetic behavior of poly(N‐2‐thiazolyl(meth)acrylamide)‐Fe(II) complexes was examined as a function of applied magnetic field at 4 K and as a function of temperature (4 ～ 300 K) at an applied magnetic field of 1 ～ 3 kOe, exhibiting the characteristics of a ferromagnet. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 83–87, 2005     

N,N′‐Pentamethylenethiuram disulfide‐ and N,N′‐pentamethylenethiuram hexasulfide‐accelerated sulfur vulcanization. I. Interaction of curatives in the absence of rubber

N,N′‐pentamethylenethiuram disulfide (CPTD), CPTD/sulfur, and N,N′‐pentamethylenethiuram hexasulfide (CPTP6) were heated in a DSC at a programmed heating rate and isothermally at 140°C. Residual reactants and reaction products were analyzed by HPLC at various temperatures or reaction times. CPTD rapidly formed N,N′‐pentamethylenethiuram monosulfide (CPTM) and N,N′‐pentamethylenethiuram polysulfides (CPTP) of different sulfur rank, CPTP of higher sulfur rank forming sequentially, as reported earlier for tetramethylthiuram disulfide (TMTD). As with TMTD, the high concentration of the accelerator monosulfide that develops is attributed to an exchange between CPTD and sulfenyl radicals, produced on homolysis of CPTD. However, a different mechanism for CPTP formation to that suggested for TMTD is proposed. It is suggested that disulfenyl radicals, resulting from CPTM formation, exchange with CPTD and/or CPTP already formed, to give CPTP of higher sulfur rank. CPTD/sulfur and CPTP6 very rapidly form a similar product spectrum with CPTP of sulfur rank 1–14 being detectable. Unlike with TMTD/sulfur, polysulfides of high sulfur rank did not form sequentially when sulfur was present, CPTP of all sulfur rank being detected after 30 s. It is proposed that sulfur adds directly to thiuram sulfenyl radicals. Recombination with sulfenyl radicals, which would be the most plentiful in the system, would result in highly sulfurated unstable CPTP. CPTP of higher sulfur rank are less stable than are disulfides as persulfenyl radicals are stabilized by cyclization, and the rapid random dissociation of the highly sulfurated CPTP, followed by the rapid random recombination of the radicals, would result in the observed product spectrum. CPTP is thermally less stable than is TMTD and at 140°C decomposed rapidly to N,N′‐pentamethylenethiourea (CPTU), sulfur, and CS₂. At 120°C, little degradation was observed. The zinc complex, zinc bis(pentamethylenedithiocarbamate), did not form at vulcanization temperatures, although limited formation was observed above 170°C. ZnO inhibits degradation of CPTD to CPTU. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2718–2731, 2000     

Synthesis,characterization, and in vitro drug‐release properties of 2‐hydroxyethyl methacrylate copolymers

2‐Hydroxyethyl methacrylate was copolymerized with acrylamide, N‐vinyl‐2‐pyrrolidone, and n‐butyl methacrylate by free‐radical solution polymerization with α,α′‐azobisisobutyronitrile as an initiator at 70 ± 1°C. The average molecular weights and molar compositions of the resultant copolymers were determined with gel permeation chromatography and ¹H‐NMR spectroscopy data, respectively. Diclofenac or 2‐[(2,6‐dichlorophenyl)amino]benzene acetic acid, a nonsteroidal anti‐inflammatory drug, was chemically attached to the copolymers by transesterification reaction in the presence of N,N′‐dicyclohexylcarbodiimide to give macromolecular prodrugs. All the synthesized polymers were characterized with Fourier transform infrared, ¹H‐, and ¹³C‐NMR spectroscopy techniques. The polymer–drug conjugates were hydrolyzed in cellophane member dialysis bags containing aqueous buffered solutions (pH 8) at 37°C, and the hydrolysis solutions were detected by UV spectrophotometer at selected intervals. The results showed that the drug could be released by selective hydrolysis of the ester bond from the side chain of the drug moiety. The release profiles of the drug indicated that the hydrolytic behavior of polymeric prodrugs strongly depends on the hydrophilicity of the polymer. The results suggest that the synthesized copolymers could be useful carriers for the release of diclofenac in controlled‐release systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2403–2409, 2007     

Forgotten monomers: access to α‐modified N‐vinylpyrrolidone polymers via C‐alkylation

Alkylation of N‐vinylpyrrolidone using lithium diisopropylamide and bis(2‐bromoethyl) ether was carried out to obtain 3‐(2‐(2‐bromoethoxy)ethyl)‐1‐vinyl‐2‐pyrrolidone ( 2 ). The derivative 2 represents a versatile starting molecule for further modification via nucleophilic displacement yielding, for example, the bicyclic 2‐vinyl‐8‐oxa‐2‐azaspiro[4.5]decan‐1‐one ( 4 ) or the ammonium salt 3‐diethoxy‐N,N′‐((dimethylbenzyl)ammonium bromide)‐1‐vinyl‐2‐pyrrolidone ( 10 ). Via free radical polymerization of 4 and 10 , the corresponding homopolymers were obtained. Copolymerization of 4 and 10 with N,N′‐diethylacrylamide yielded water‐soluble materials. The thermosensitive solubility of copolymers poly[(2‐vinyl‐8‐oxa‐2‐azaspiro[4.5]decan‐1‐one)‐co‐(N,N′‐diethylacrylamide)] and poly[(3‐diethoxy‐N,N′‐((dimethylbenzyl)ammonium bromide)‐1‐vinyl‐2‐pyrrolidone)‐co‐(N‐vinylpyrrolidone)] in water was investigated. © 2015 Society of Chemical Industry     

Chemical structure of poly(β‐cyclodextrin‐co‐citric acid)

We synthesized water‐insoluble polymers, poly(β‐cyclodextrin‐co‐citric acid)s, by heating a mixture of citric acid, cyclodextrin (CD), and Na₂HPO₄ as a catalyst with a 6 : 1 : 2 molar ratio at 160, 170, and 180°C for 10 and 20 min. The chemical composition of the polyesters was determined by high pressure liquid chromatography (HPLC) analysis of the polymer hydrolysates. The crosslinking mechanisms and thermal degradation of the polymers were also investigated. The polyesters contained 30–35% citric acid, 1–4% unsaturated carboxylic acids (i.e., itaconic, cis‐aconitic, trans‐aconitic, and mesaconic acids), and 60–70% CD, whereas about 40% of them were able to form inclusion complexes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011