Effect of crosslinked structure on SO2 gas sorption properties in amino‐functional copolymers

SO₂ gas sorption properties were examined for poly(styrene‐co‐chloromethyl styrene) functionalized with N,N‐dimethyl‐1,3‐propanediamine (DMPDA). The DMPDA‐functional copolymers were prepared under various reaction conditions. Two types of SO₂ sorption behaviors were observed for these DMPDA‐functional copolymers: SO₂ sorption capacity was very high irrespective of slow sorption/desorption rates (type I), and the sorption/desorption rates were very fast while SO₂ sorption capacity was small (type II). Fourier transform infrared analysis and dielectric loss measurement revealed that the type II sorption behavior was obtained for the highly crosslinked DMPDA‐functional copolymers. The degree of crosslinking was affected by both the solvent used to react DMPDA with the copolymer and the percent conversion of the chloromethyl styrene group. It was confirmed that DMPDA‐functional copolymers having a highly crosslinked structure are suitable materials in quartz crystal microbalance (QCM)‐type polymeric SO₂ gas sensors. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2982–2987, 2003     

Metal ion interaction of water‐soluble copolymers containing carboxylic acid groups in aqueous phase by membrane filtration technique

This article reports the synthesis of poly(N‐maleoylglycine‐co‐itaconic acid) by radical copolymerization under different feed mole ratios and its properties to remove various metal ions, such as Cu(II), Cr(III), Co(II), Zn(II), Ni(II), Pb(II), Cd(II), and Fe(III), in aqueous phase with the liquid‐phase polymer‐based retention(LPR) technique. The interactions of inorganic ions with the hydrophilic water‐soluble polymer were determined as a function of pH and filtration factor. Metal ion retention was found to strongly depend on the pH. Metal ion retention increased as pH and MG content units in the macromolecular backbone increased. The copolymers were characterized by elemental analysis, FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopy. Additionally, intrinsic viscosity, molecular weight, and polydispersity have been determined for the copolymers. Copolymer and polymer–metal complex thermal behavior was studied using differential scanning calorimetry (DSC) and thermogravimetry (TG) techniques under nitrogen atmosphere. The thermal decomposition temperatures (TDT) were influenced by the copolymer composition. The copolymers present lower TDT than the polymer–metal complex with the same copolymer composition. All copolymers present a single T_g, indicating the formation of random copolymers. A slight deviation of the T_g for the copolymers and its complexes can be observed. The copolymer T_g is higher than the T_g value for the polymer–metal complexes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation and sorption studies of microsphere copolymers containing β-cyclodextrin and poly(acrylic acid)

Microsphere polymeric materials containing β-cyclodextrin (β-CD) and poly(acrylic acid) (PAA) with tunable morphologies were prepared in order to improve their sorption characteristics in aqueous solution. The microsphere polymeric materials were prepared using a (water/oil) micro-emulsion-evaporation technique to condense β-cyclodextrin (β-CD) with PAA at various comonomer ratios and mixing speeds. The β-CD microsphere copolymers were characterized using FTIR, TGA, DSC, SEM, elemental (C and H) microanalyses, and solid state ¹³C-NMR spectroscopy. The sorption properties of the polymeric materials at 295 K in aqueous solution containing p-nitrophenol (PNP) were studied using a dye-based method with UV–Vis spectrophotometry at pH 4.6 and 10.3. The sorption isotherms of copolymer/PNP systems were evaluated with various isotherm models (e.g., Langmuir, BET, Freundlich, and Sips). The Sips isotherm showed the best overall agreement with the experimental results and the sorption parameters provided estimates of the sorbent surface area (12.0–331 m²/g) and the sorption capacity (Q_m = 0.359–2.20 mmol/g at pH = 4.6; Q_m = 0.070–0.191 mmol/g at pH = 10.3) for the microsphere copolymer/PNP systems in aqueous solution. The nitrogen adsorption properties of the microporous copolymers in the solid state were obtained at 77K with BET surface areas ranging from 0.275 to 4.47 m²/g. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Gas‐sorption properties of 6FDA–durene/1,4‐phenylenediamine (pPDA) and 6FDA–durene/1,3‐phenylenediamine (mPDA) copolyimides

We investigated the sorption isotherms of O₂, N₂, CH₄, and CO₂ gases in 6FDA–durene, 6FDA–1,4‐phenylenediamine (6FDA–pPDA), and 6FDA–1,3‐phenylenediamine (6FDA–mPDA) homopolymers and 6FDA–durene/pPDA and 6FDA–durene/mPDA copolyimides. The solubilities decrease in the order of the inherent condensabilities of the penetrant gases, namely, CO₂, CH₄, O₂, and N₂. The chemical structures of the polymer, as well as the chain packing, determine the sorption properties of these homopolymers and copolymers. The FDA–durene homopolymer has the highest solubility for all gases because of its high specific free volume and fractional free volume. The solubilities of the copolymers increase with an increasing 6FDA–durene content, while the solubility selectivities of the copolymers only vary slightly. The values of K_D (Henry's law constant) and C_H′ (Langmuir site capacity) of these copolyimides decrease with a decreasing 6FDA–durene content. To our surprise, contradictory to the previous known fact that the meta‐connected materials tend to have denser molecular packing than that of the para‐linked materials for homopolymers, the 6FDA–durene/mPDA 80/20 copolymer has higher gas solubilities than those of the 6FDA–durene/pPDA 80/20 copolymer. The random moiety sequence within the copolymer may be the main cause for the abnormal phenomenon. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2187–2193, 2003     

Preparation and characterization of chitosan/Cu(II) affinity membrane for urea adsorption

We used silica particles as a porogen to prepare macroporous chitosan membranes and subsequently prepared macroporous chitosan/Cu(II) affinity membranes for urea adsorption. The morphology, porosity, Cu(II) adsorption capacity, and swelling ratio of the macroporous membrane were measured. SEM photographs show the pores in the membrane dispersed uniformly, a feature that didn't change much after the adsorption of Cu(II). The porosity of the membrane had a maximum value when the silica/chitosan ratio was about 12. The Cu(II) adsorption capacity in the membrane leveled off when the initial concentration of CuSO₄ solution exceeded 5 × 10^?2 mol/L. The macroporous chitosan/Cu(II) affinity membrane was successfully used for urea adsorption. The maximum urea adsorption capacity was 78.8 mg/g membrane, which indicates that the membrane has a great potential for hemodialysis for urea removal. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1108–1112, 2003     

Preparation,characterization, and metal ion retention capacity of Co(II) and Ni(II) from poly(p‐HO‐ and p‐Cl‐phenylmaleimide‐co‐2‐hydroxypropylmethacrylate) using the ultra filtration technique

p‐Chlorophenylmaleimide and p‐hydroxyphenylmaleimide with 2‐hydroxypropyl methacrylate were synthesized by radical polymerization, and the metal ion retention capacity and thermal behavior of the copolymers were evaluated. The copolymers were obtained by solution radical polymerization with a 0.50 : 0.50 feed monomer ratio. The maximum retention capacity (MRC) for the removal of two metal ions, Co(II) and Ni(II) in aqueous phase were determined using the liquid‐phase polymer based retention technique. Inorganic ion interactions with the hydrophilic polymer were determined as a function of pH. The metal ion retention capacity does not depend strongly on the pH. Metal ion retention increased with an increase of pH for a copolymer composition 0.50 : 0.50. At different pH, the MRC of the poly(p‐chlorophenylmaleimide‐co‐2‐hydroxypropylmethacrylate) for Co(II) and Ni(II) ions varied from 44.1 to 48.6 mg/g and from 41.5 mg/g to 46.0 mg/g, respectively; while the MRC of poly(p‐hydroxyphenylmaleimide‐co‐2‐hydroxypropyl methacrylate) for Co(II) and Ni(II) ions varied from 28.4 to 35.6 mg/g and from 27.2 to 30.8 mg/g, respectively. The copolymers and copolymer–metal complexes were characterized by elemental analysis, FT‐IR, ¹H NMR spectroscopy, and thermal behavior. The thermal behavior of the copolymer and polymer–metal complexes were studied using differential scanning calorimetry and thermogravimetry techniques under nitrogen atmosphere. The thermal decomposition temperature and T_g were influenced by the binding‐metal ion on the copolymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Tailoring copper (II) methacrylate‐containing copolymers and its use as electrode modifier agent in electroanalytical applications

This work focuses on the synthesis of a new class of copolymer materials consisting of traditional vinyl monomers (essentially, vinyl acetate, ethyl acrylate, and methyl methacrylate) and copper (II) methacrylate (Cu(II)MA) intended to be used as surface modification agents in electrochemical quantifications of organic and inorganic analytes. Voltammetry assays showed that when deposited on glassy‐carbon electrode (GCE), Cu(II)MA‐based copolymers are very promising materials to be applied in electrochemical determinations, exhibiting high analytical signal in the oxidation and reduction peaks during quantification of potassium hexacyanoferrate (III) in comparison to a bare GCE, contributing to increase the effective electrode area. When employed for the determination of ascorbic acid, PVAcCu(II)MA/GCE exhibited performance similar to that of the bare GCE. Polymers characterizations showed that glass transition temperature of the Cu(II)MA‐based materials increased in approximately 10–20°C, as consequence of the copper present in molecular structure of the copolymer chains (bidentate bridging coordination mode). Energy‐dispersive X‐ray spectroscopy measurements of Cu(II)MA monomer and Cu(II)MA‐based copolymers showed strong characteristic peaks Kα and Kβ at 8.04 and 8.90 keV, respectively, with an average amount of copper of 99%. The performance of the Cu(II)MA‐based copolymers modified electrodes is strongly dependent on the amount of copper into the copolymer chains and consequently on the monomers conversion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43202.     

Pentacyanoferrate(II) complexes with chitosan

New organic–inorganic materials based on products of interaction between sodium aminoprusside and polymer ligand (chitosan) have been synthesized. The composition of the obtained materials was characterized using the element analysis and X‐ray diffraction; the Fourier transform infrared (FT‐IR) spectroscopy and Thermogravimetric analysis data were used to propose the structure of the formed complexes. It was established that ion and ligand exchange were the main reactions at interaction of sodium aminoprusside with water‐soluble chitosan salts. The comparative estimation of the sorption capacity with respect to cesium ions was performed for the synthesized complexes. It has been shown that the complex of chitosan with pentacyanoferrate(II) in the form of cobalt(II) salt has higher distribution coefficient with respect to Cs⁺ ions, as compared to cobalt aminoprusside. The maximum sorption capacity value for Cs⁺ was evaluated from the sorption isotherm and found to be equal to 0.3 mmol/g. POLYM. ENG. SCI., 54:2392–2397, 2014. © 2013 Society of Plastics Engineers     

Metal ion sorption by chitosan–tripolyphosphate beads

Heavy metal removal from wastewater is crucial for the proper management of discharged water from mining operations. This residual water is typically unusable for other purposes such as for human/animal, crop, or industrial consumption. Eco‐friendly adsorption materials are necessary to ensure the sustainable treatment of this wastewater. Therefore, the sorption of Cu(II), Cd(II), Pb(II), and Zn(II) ions onto chitosan–tripolyphosphate (CTPP) beads was investigated using real mining wastewater and prepared ion metal solutions. The effects of pH, contact time, temperature, selectivity, and maximum sorption capacity in successive batches at different concentrations were studied. The optimum sorption of cations, except for copper (pH 3) was found at pH 5. Equilibrium in the adsorption of all metals was reached at 24 h of contact. Studies of the maximum sorption capacity at different concentrations showed that the CTPP beads could adsorb 158, 55, 47, and 47 mg/g of Pb(II), Cu(II), Cd(II), and Zn(II), respectively. Experimental data for the sorption of Pb(II) were optimally correlated with the Langmuir model. The thermodynamic parameters such as the changes in enthalpy (ΔH⁰), entropy (ΔS⁰), and free energy (ΔG⁰) were determined. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45511.     

Membrane-encapsulated controlled-release urea fertilizers based on acrylamide copolymers

About 40–70% of the applied urea fertilizer is lost to the environment, causing serious pollution. Controlled-release technology is useful in increasing the efficiency of fertilizer urea as well as in checking environment pollution. Four laboratory-level controlled-release urea fertilizers were formulated based on polymers which are soil conditioners and then evaluated for their slow-release property. Urea was coated with the copolymer of acrylamide and divinylbenzene/N,N′-methylenebisacrylamide /tetraethyleneglycol diacrylate or pentaerythritol triacrylate and sealant materials (wax and polystyrene). Urea coated with co-polymer of acrylamide-tetraethyleneglycol diacrylate was found to be having a better slow-release property among the systems prepared. © 1996 John Wiley & Sons, Inc.     

Synthesis,characterization, and application of yeast-based magnetic bionanocomposite for the removal of Cu(II) from water

Abstract

Due to the amount of yeast residues generated by the industries and their high capacity as biosorbent, this work proposes the use of yeast biomass in natura (YB) or modified with ferromagnetic nanoparticles (Fe₃O₄) (YB-MNP) for Cu(II) removal from water. Synthesized YB-MNP, YB, and magnetite alone (MNP) were characterized by FTIR, XRD, and SEM. It was observed the efficient impregnation of magnetite on the surface of the biomass. Copper sorption was evaluated in batch tests using 100?mg/L of Cu(II) solution at pH 5.5, and the supernatant was analyzed by FAAS for Cu determination. Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) isotherm models were applied to fit the experimental data. A favorable sorption process was observed for all the materials, mainly for the D–R model adjusted to the bionanocomposite data (YB-MNP), with r² = 0.9950 and a low error (χ² = 0.0427) associated to the model. Theoretical and experimentally Cu(II) sorption capacities were fairly similar, 8.6?±?0.1 and 8.3?±?0.2?mg/g, respectively.     

Voltammetric investigation of polyelectrolyte-Cu(II) complexes

The complexation behaviours of poly(N-vinylcarbazole) (PNVCz), poly(acrylic acid) (PAA) poly(itaconic acid) (PIA) and their copolymers, synthesized by using different initial monomer compositions, with Cu(II) ions were investigated by the voltammetric technique. Their solutions were prepared in THF-water mixture according to the water-insoluble nature of PNVCz and its copolymers. The polymeric ligand-Cu(II) interactions, i.e. complex formations were studied as a function of copper ion concentration and copolymer composition. It was observed that although the cyclic voltammogram (CV) of Cu(II) alone in THF-water mixture was characterized by one redox wave, which has an irreversible nature, it became more reversible in the presence of polymer. Further, the CV results indicated the presence of two different electron transfer mechanisms, depending on the n _COOH/n _Cu(II) ratio and the carboxyl content of the copolymers.     

Removal of Copper and Lead from Aqueous Solution by Adsorption onto Cross-Linked Chitosan/Montmorillonite Nanocomposites in the Presence of Hydroxyl–Aluminum Oligomeric Cations: Equilibrium,Kinetic, and Thermodynamic Studies

Adsorption removal of Cu (II) and Pb (II) on cross-linked chitosan/Al₁₃-pillared montmorillonite (CCPM) was examined in solutions. The chitosan dosage was drastically reduced in the new nanocomposite, which is made from the treated clay (Al₁₃-pillared montmorillonite). Several important parameters that influenced the adsorption of Cu (II) and Pb (II) ions, such as cross-linked chitosan-to-clay ratio, pH, temperature, initial concentration, dosage, and contact time effect, were systematically investigated. Result showed that in the nanocomposite with cross-linked chitosan-to-clay ratio of 0.45:1, the maximum removal efficiencies of Cu (II) [pH 6.5, dosage 10 g/L, initial Cu (II) concentration 100 mg/L, contact time 2 h, 298 K] and Pb (II) [pH 6.0, dosage 5 g/L, initial Pb (II) concentration 100 mg/L, contact time 2 h, 298 K] were 96.0% and 99.5%, respectively. Kinetic and isotherm studies have indicated that the adsorption process of Cu (II) or Pb (II) nanocomposites was better fitted by the pseudo-second-order equation and the Freundlich equation, with chemical adsorptions as the rate-limiting step. The metal–ion affinity to the functional groups of CCPM followed the order Pb (II) > Cu (II). The thermodynamic parameters ΔH and ΔS values showed that the sorption process of Cu (II) or Pb (II) was spontaneous (ΔG < 0), was endothermic (ΔH < 0), and had decreased entropy (ΔS < 0). HNO₃ (0.1 M) could be a good desorbent in the recovery of metal ions after adsorption and regeneration of the adsorbent.     

New polymeric structures designed for the removal of Cu(II) ions from aqueous solutions

New polymeric structures obtained by chemical transformations of maleic anhydride/dicyclopentadiene copolymer with triethylenetetraamine, p‐aminobenzoic acid, and p‐aminophenylacetic acid were used for the removal Cu(II) ions from aqueous solutions. The experimental values prove the importance of the chelator nature and of the macromolecular chain geometry for the retention efficiency. The retention efficiency (η_r), the retention capacity (Q _e ), and the distribution coefficient of the metal ion into the polymer matrix (K _d ) are realized by evaluation of residual Cu(II) ions in the effluent waters, by atomic adsorption. Also are discussed the influence of pH, the thermal stability of the polymer, and their polymer–metal complex, as well as the particular aspects regarding the contact procedure and the batch time. Based on the polymers and polymer–metal complexes characterization a potential retention mechanism is proposed. All polymer supports as well theirs metal–complexes are characterized by ATD and FTIR measurements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1397–1405, 2007     

Drug‐release behavior of chitosan‐g‐poly(vinyl alcohol) copolymer matrix

Chitosan‐g‐poly(vinyl alcohol) (PVA) copolymers with different grafting percent were prepared by grafting water‐soluble PVA onto chitosan. The drug‐release behavior was studied using the chitosan‐g‐PVA copolymer matrix containing prednisolone in a drug‐delivery system under various conditions. The relationship between the amount of the released drug and the square root of time was linear. From this result, the drug‐release behavior through the chitosan‐g‐PVA copolymer matrix is shown to be consistent with Higuchi's diffusion model. The drug‐release apparent constant (K_H) was slightly decreased at pH 1.2, but increased at pH 7.4 and 10 according to the increasing PVA grafting percent. Also, K_H was decreased by heat treatment and crosslinking. The drug release behavior of the chitosan‐g‐PVA copolymer matrix was able to be controlled by the PVA grafting percent, heat treatment, or crosslinking and was also less affected by the pH values than was the chitosan matrix. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 458–464, 1999     

Formation of thermosensitive water‐soluble copolymers with phosphinic acid groups and the thermosensitivity of the copolymers and copolymer/metal complexes

Thermosensitive and water‐soluble copolymers were prepared through the copolymerization of acryloyloxypropyl phosphinic acid (APPA) and N‐isopropyl acrylamide (NIPAAm). The thermosensitivity of the copolymers and copolymer/metal complexes was studied. The APPA–NIPAAm copolymers with less than 11 mol % APPA moiety had a lower critical solution temperature (LCST) of approximately 45°C, but the APPA–NIPAAm copolymers with greater than 21 mol % APPA moiety had no LCST from 25 to 55°C. The APPA–NIPAAm copolymers had a higher adsorption capacity for Sm³⁺, Nd³⁺, and La³⁺ than for Cu²⁺, Ni²⁺ and Co²⁺. The APPA–NIPAAm (10:90) copolymer/metal (Sm³⁺, Nd³⁺, or La³⁺) complexes became water‐insoluble above 45°C at pH 6–7, but the APPA–NIPAAm (10:90) copolymer/metal (Cu²⁺,Ni²⁺, or Co²⁺) complexes were water‐soluble from 25 to 55°C at pH 6–7. The temperature at which both the APPA–NIPAAm copolymers and the copolymer/metal complexes became water‐insoluble increased as the pH values of the solutions increased. The APPA–NIPAAm copolymers were able to separate metal ions from their mixed solutions when the temperature of the solutions was changed; this was followed by centrifugation of the copolymer/metal complexes after the copolymers were added to the metal solutions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 116–125, 2004     

Bioengineering functional copolymers. XI. Copper(II)-poly(N-vinyl-2-pyrrolidone-co-N-isopropylacrylamide) macrocomplexes

A series of poly(N-vinyl-2-pyrrolidone-co-N-isopropylacrylamide)s, poly(VP-co-NIPA) copolymers with different compositions were prepared by radical copolymerization of VP and NIPA in N,N′-dimethylformamide at 65°C using 2,2′-azobisisobutyronitrile as initiator. Cu(II)-copolymer macrocomplexes were prepared by complexation of the copolymers with copper sulfate in aqueous solution at 40°C. The structure and composition of the copolymers, and the formation of coordinated Cu(II)-complexes between amide VP units and Cu²⁺ ions, were studied by FTIR spectroscopy, DSC and TGA-DTG in addition to electrical conductivity. Studies on the relationship between composition and thermal behavior showed that the values of T_g and T_d of the copolymers and their coordinated macrocomplexes increased with increasing VP content. The copolymers predominantly show amorphous structure while their Cu(II)-macrocomplexes show the presence of a crystalline phase. The conductive properties of the synthesized Cu(II)-poly(VP-co-NIPA) complexes are also discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Soybean hull functionalized by phosphoric acid for sorption of copper from aqueous solution

One kind of potentially biodegradable cationic sorbent, which bears hydroxyl groups of phosphoric acid as its functional groups, with high sorption capacity of copper was prepared by thermochemically esterifying phosphoric acid (PA) onto soybean hull. Sorption of Cu(II) from aqueous solution onto modified soybean hull (MSH) was investigated in a batch system. The sorption experiments were performed under various conditions such as different initial pH, copper concentration, MSH dosage, and contact time. The maximum copper sorption was obtained when initial solution pH≥3.5. The isothermal data of copper sorption fitted the Langmuir model and the sorption process could be described by the pseudo-first-order kinetic model. The maximum sorption capacity (Q _m ) of MSH for Cu(II) was 31.55 mg/g. For 100 mg/l of Cu(II) solution, a sorption ratio above 91% could be achieved by 5.0 g/l of MSH. The equilibrium of Cu(II) sorption was reached within 50 min. The foreign cation and chelator in Cu(II) solution caused decline of Cu(II) sorption.     

Facile preparation of magnetic chitosan modified with thiosemicarbazide for adsorption of copper ions from aqueous solution

In this study, magnetic chitosan modified with thiosemicarbazide (TSC‐Fe₃O₄/CTS) was facilely synthesized with glutaraldehyde as the crosslinker, and its application for removal of Cu(II) ions was investigated. The as‐prepared TSC‐Fe₃O₄/CTS was characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray powder diffraction (XRD), and scanning electron microscopy (SEM). The results showed that TSC‐Fe₃O₄/CTS has high adsorption capacity and selectivity towards Cu(II) ions. Adsorption experiments were carried out with different parameters such as pH, solution temperature, contact time and initial concentration of Cu(II) ions. The adsorption process was better described by the pseudo‐second‐order model. The sorption equilibrium data was fitted well with the Langmuir isotherm model and the maximum adsorption capacity toward Cu(II) ions was 256.62 mg/g. The thermodynamic parameters indicated that the adsorption process of Cu(II) ions was exothermic spontaneous reaction. Moreover, this adsorbent showed excellent reusability and the adsorption property remained stable after five cycles. This adsorbent is believed to be one of the promising and favorable adsorbent for the removal of Cu(II) ions from aqueous solution. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44528.     

ABA triblock copolymers from poly(p‐dioxanone) and poly(ethylene glycol)

Poly(p‐dioxanone)–poly(ethylene glycol)–poly(p‐dioxanone) ABA triblock copolymers (PEDO) were synthesized by ring‐opening polymerization from p‐dioxanone using poly(ethylene glycol) (PEG) with different molecular weights as macroinitiators in N₂ atmosphere. The copolymer was characterized by ¹H NMR spectroscope. The thermal behavior, crystallization, and thermal stability of these copolymers were investigated by differential scanning calorimetry and thermogravimetric measurements. The water absorption of these copolymers was also measured. The results indicated that the content and length of PEG chain have a greater effect on the properties of copolymers. This kind of biodegradable copolymer will find a potential application in biomedical materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1092–1097, 2006