Homogeneous graft copolymerization of styrene onto cellulose in a sulfur dioxide–diethylamine–dimethyl sulfoxide cellulose solvent

Graft copolymerization of styrene onto cellulose was studied in a homogeneous system (SO₂–DEA–DMSO medium) by γ-ray mutual irradiation technique. At the same time, homopolymerization of styrene was also examined separately in DMSO, SO₂–DMSO, DEA–DMSO, and SO₂–DEA–DMSO media by the same technique. Polymerization of styrene hardly occurs on concentrations above 10 mole SO₂–DEA complex per mole glucose unit. Maximum percent grafting was obtained in concentrations of 4 mole, after which it decreased rapidly. Total conversion and percent grafting increased with the irradiation time. The value (=0.55) of the slope of the total conversion rate plotted against the dose was only a little higher than the 1/2 which was expected from normal kinetics. No retardation in homopolymerization of styrene in DMSO, SO₂–DMSO, and DEA–DMSO was evident, while the retardation of homopolymerization in the SO₂–DEA–DMSO medium was measurable. Sulfur atoms were detected in the polymers obtained in both of SO₂–DMSO and SO₂–DEA–DMSO solutions. All of the molecular weights of polymers obtained in the present experiment were very low (3.9 × 10³?1.75 × 10⁴).     

Performance evaluation of sodium alginate–Pebax polyion complex membranes for application in direct methanol fuel cells

A novel polyion complex membrane was synthesized for direct methanol fuel cell application through the blending of the natural biopolymer sodium alginate (SA) with the synthetic polymer Pebax [poly(ether‐block ‐amide)]. The blend was covalently crosslinked with glutaraldehyde (GA) and sulfonated with sulfuric acid (H₂SO₄), after which characterization by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffractometry, thermogravimetric analysis, and universal testing machine techniques was carried out. The SA–Pebax–GA–H₂SO₄ membrane exhibited a high ion‐exchange capacity of 2.1 mequiv/g, an optimum water sorption of 17.3%, and a low methanol sorption of 9.5%. A desirably low methanol permeability of 9.25 × 10^?8 cm²/s and a high proton conductivity of 0.067 S/cm were obtained as against corresponding values of 1.82 × 10^?6 cm²/s and 0.077 S/cm reported for a commercial Nafion 117 membrane. Moreover, a high selectivity of 6.5 × 10⁵ Ss/cm³ with a power density of 0.17 W/cm² was achieved with the indigenous blend membrane at a potential of 0.34 V. Molecular dynamics simulation was performed along with the estimation of fractional free volume to explain the transport behavior of water and methanol molecules through the membrane. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44485.     

Stripping of Rh–Sn–Cl‐loaded alkylated 8‐hydroxyquiniline with Na2SO3–HCl

Acidic rhodium(III) chloride solutions pretreated with SnCl₂ at a ratio Sn(II) : Rh(III) = 3 are contacted with an alkylated 8‐hydroxyquinoline (Kelex 100) to prepare loaded organics which subsequently are subjected to stripping with Na₂SO₃–HCl solutions. Rh(III) was found to be stripped selectively involving the following reaction: where H₂Q is the protonated form of kelex 100. Direct characterization of the stripped complex and slope analysis confirmed this stripping reaction. Equilibrium was reached within 20 min. A kinetic analysis found the stripping process to be irreversible and to be controlled most probably by the slow release of SnCl₃^? ligand from the intermediate Rh–Q–SO₃–SnCl₃ organic complex. Copyright © 2004 Society of Chemical Industry     

Thermal and rheological behavior of acrylonitrile–carboxylic acid copolymers and their metal salt complexes

The influence of acrylic, methacrylic, and itaconic acid comonomers in the nitrile oligomerization of acrylonitrile copolymers has been studied by DSC and DSC‐FTIR in air and nitrogen atmospheres. Addition of metal salts in poly(acrylonitrile–acrylic acid) copolymer, PA on thermal and rheological behavior has also been reported. Incorporation of CuSO₄, FeSO₄, ZnSO₄, and Al₂ (SO₄)₃ (1 to 5 wt %) salt in the polymer solution affects its solubility in DMF. The complexes of PA with zinc sulphate, took a longer time to dissolve in DMF, whereas the complexes with Fe(SO₄) and Al₂(SO₄)₃ are almost insoluble in DMF, perhaps due to intermolecular crosslinking. Addition of these metal salts to the PA solution also affects its Brookfield viscosity. The viscosity of 10 wt % polymer solution increases from 400 centipoise (Cps) to 1090 Cps for complex with 5% FeSO₄ (on the weight of dope solids) and 690 Cps for Al₂ (SO₄)₃ and 906 cps for ZnSO₄ complex. However, for CuSO₄ salt complex this value is 770 Cps. FTIR spectra shows the participation of COOH and CN group in the complex formation, which is responsible for enhanced Brookfield viscosity. Thermal behavior of the polymer–metal salt complex showed that these salts also affect the exothermic reaction. The initiation of cyclization reaction takes place at a lower temperature compared to neat acrylonitrile–acrylic acid copolymer. However, the heat liberated per unit time in N₂ atmosphere in case of neat polymer is 6.3 Jg⁻¹ min⁻¹, which reduces to 5.5 Jg⁻¹ min⁻¹ in the case of the PA/Al complex, confirming the role of Al₂ (SO₄)₃ in retarding the rate of cyclization reaction. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 567–582, 1999     

Cyanuric acid–epichlorohydrin prepolymers

In this study, we investigated the reaction of cyanuric acid and epichlorohydrin (ECH). SnCl₄ was used as a catalyst. Several reaction conditions were tested, and the products were analyzed by means of Fourier transform infrared and ¹H‐NMR spectroscopy, hydroxyl group content, molar mass, elemental and thermal analysis, viscosity, and density. ECH reacted with the amine groups of the cyanuric acid ring to form lateral chains that contained chloroalkyl and hydroxyl end groups. Full substitution of the amine groups was observed in all of the synthesized products. The solvent used in the synthesis was found to be very important for the structure of the final prepolymers. When N,N‐dimethylformamide was used, relatively low‐molar‐mass prepolymers of cyanuric acid and ECH were obtained. When solvents with low dielectric constants were used, no reaction with cyanuric acid was observed. The prepared prepolymers were thermally stable up to 160°C. At this temperature, degradation started via the lateral chains. The viscosity of the products decreased as the ECH–cyanuric acid ratio increased, whereas the density remained basically constant. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3684–3691, 2006     

Polyaniline–13X zeolite composite‐supported platinum electrocatalysts for direct methanol fuel cell applications

We successfully synthesized 13X zeolite using a hydrothermal method. Then, composites of polyaniline (PANI) with 13X zeolite and PANI–13X with platinum were prepared by chemical oxidative polymerization and chemical reduction, respectively. Field emission scanning electron microscopy, X‐ray diffraction, Raman spectroscopy and Brunauer–Emmett–Teller techniques were used to characterize the PANI–Pt and PANI–Pt–13X composites. Further, the electrocatalytic activity towards methanol oxidation of the synthesized catalysts was explored using cyclic voltammetry in 1 mol L^?1 CH₃OH + 0.5 mol L^?1 H₂SO₄ solution. From the obtained results, PANI–Pt–13X shows superior performance compared to PANI–Pt towards methanol oxidation and electrical conductivity. Hence, the 13X zeolite‐incorporated PANI–Pt composite could be an efficient catalyst for direct methanol fuel cell applications. © 2019 Society of Chemical Industry     

Ultraviolet spectra and structure of zinc–cellulose complexes in zinc chloride solution

The spectral characteristics of aqueous zinc chloride solutions (67% w/w) containing cellulose, cellobiose, maltose, β‐methyl glucoside, and glucose were compared. The results suggest that zinc ion forms loose complexes with the C2 or C3 hydroxyl groups of glucose or methyl glucopyranoside. The absorption of light in the 200–220 nm range indicates the formation of these types of complexes. In solutions containing cellobiose or cellulose, zinc ion forms complexes with the hemiacetal oxygen atom of the anhydroglucose at the nonreducing end and a hydroxyl group of an anhydroglucose unit at the reducing end. This type of complex absorbs at 290 nm. Light absorption of cellobiose solutions at 235 nm was also correlated with similar complexes involving the anomeric oxygen at the reducing end of cellobiose. The absorption at 290 nm was proportional to the zinc chloride concentration. The presence of calcium ion also enhances the absorption; however, ion alone cannot form a complex with cellulose. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1441–1446, 1999     

Electron spin resonance studies of interactions of ammonia,copper, and cupriammonia with cellulose

The electron spin resonance spectra (ESR) of complexes of copper with fibrous cotton cellulose under various experimental conditions were determined. Cupric ions dissolved in solutions of strong bases, such as concentrated ammonium hydroxide, sodium hydroxide, and potassium hydroxide, formed complexes with fibrous cotton cellulose. These complexes had paramagnetic resonance properties and generated characteristic ESR spectra. Cupric ions dissolved in solutions of highly ionized neutral salts, such as sodium chloride, formed complexes with cellulose. These complexes also generated the same characteristic ESR spectra as the complexes formed in solutions of strong base. The reaction between cupric ions and cellulose was evidently very rapid and reversible. When the concentration of ammonia was decreased in, or ammonia was removed from, the cupric ion–ammonium hydroxide–cellulose complexes, the paramagnetic resonance properties of the complex were decreased or lost. Similar results were received when potassium hydroxide was removed from the complexes. The compositions of the complexes evidently are variable, that is, under different experimental conditions the relative intensities of the lines of the ESR spectra of the complexes varied, although the hyperfine splittings of the lines were constant. It was concluded that reactions of cupric ions to form complexes with adjacent hydroxyl groups on the cellulose molecule depended on an optimum spatial arrangement of the hydroxyl groups, that is, distance between the groups. Evidently, wetting of cotton cellulosic fibers with solutions of strong bases or neutral salt allowed rotation about the C₂–C₃ bond to yield this optimum arrangement. When the base or salt was removed, rotation occurred to give less favorable positions of the hydroxyl groups for complexing with cupric ions.     

1,2‐propanediol–cellulose–acrylamide graft copolymers

1,2‐Propanediol–cellulose–acrylamide graft copolymers (PCACs) were developed for enhanced oil recovery. They were prepared with acrylamide and 1,2‐propanediol (PDO)–cellulose, which was formed through the addition of glycols to cellulose by the Shotten–Baumann reaction between 3‐chloro‐1,2‐propanediol and cellulose. The graft copolymerization was initiated with a redox system between Ce⁴⁺ and glycols in cellulose. The infrared spectrum of PDO–cellulose had some characteristic absorption bands around 2960 (νC? H) and 1050 cm^?1 (νC? O) that also appeared for the PDO group and pyranose ring of cellulose, respectively. The rate of Ce⁴⁺ consumption by PDO–cellulose was investigated through the calculation of the overall kinetic constant from the slopes of ln(D ? D_R) versus time (where D is the absorbance and D_R is the absorbance of the original polysaccharide solution) The results showed that PDO–cellulose had high reactivity and that there were two mechanisms of oxidation by Ce⁴⁺ with PDO–cellulose. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3022–3029, 2004     

Copper–amine complexes as new catalysts for rigid polyurethane foam preparations

A new class of catalyst for the preparation of rigid polyurethane (RPUR) foams was developed. Metal(II)–amine complexes [M(en)₂ and M(trien), where M = Cu or Ni, en = ethylenediamine, and trien = triethylenetetramine] were synthesized and used as catalysts in the preparation of RPUR foams. The catalytic activity of the metal(II)–amine complexes and properties of the RPUR foams were investigated and compared to those prepared by N,N‐dimethylcyclohexylamine (DMCHA), which is a common commercial tertiary amine catalyst used in the preparation of RPUR foams. The use of M(en)₂ and M(trien) can improve the working environment in RPUR foam processing because DMCHA and other commercial tertiary amine catalysts have a strong odor, whereas M(en)₂ and M(trien) do not have any odor. The reaction times in RPUR foam preparation, namely, cream time, gel time, tack‐free time, and rise time, were investigated. These data indicated that the copper–ethylenediamine complex [Cu(en)₂] and copper–triethylenetetramine complex [Cu(trien)] had comparable catalytic activity to DMCHA, whereas the catalytic activity of the nickel complexes was not good. Attenuated total reflection–IR spectroscopy of the RPUR foams prepared with Cu(en)₂ and Cu(trien) showed quantitative isocyanate (NCO) conversion. The density and compressive strength of the RPUR foams prepared from Cu(en)₂ and Cu(trien) were comparable to those prepared from DMCHA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Magnetic behavior of polycarbosilazane ?FeII, ?FeIII and mixed‐valence ?FeII–III chloride metallopolymers

Fe^II, Fe^III and mixed‐valence Fe^II–III chlorides were reacted with poly[N,N′‐bis(dimethylsilyl)ethylenedi‐ amine], [? Si(CH₃)₂NHCH₂CH₂NH? ]_n, to form the corresponding Fe‐polycarbosilazane macromolecular complexes. The average chain–chain spacing in these materials was estimated from X‐ray diffraction data and found to be 6.94, 7.29, 7.30 and 7.45 Å in metal‐free and Fe^II? , Fe^III? and Fe^II–III‐containing polycarbosilazanes, respectively. This demonstrates that Fe^II, Fe^III and Fe^II–III chlorides are encapsulated between the polycarbosilazane chains. The chain–chain expansions in the divalent Fe^II and trivalent Fe^III chloride macromolecular complexes are comparable, but less than that in the Fe^II–III chloride analog, which suggests that different chain–chain packings exist in the mixed‐valence macromolecular complex. The magnetic properties of the resulting complexes were investigated by measuring the magnetization in magnetic fields up to 8 kOe and in the temperature range from liquid nitrogen temperature to room temperature. Copyright © 2007 Society of Chemical Industry     

Evaluation of the Performance of Carbon Supported Pt–Ru–Ni–P as Anode Catalyst for Methanol Electrooxidation

This research is aimed to improve the activity and stability of ternary alloy Pt–Ru–Ni/C catalyst. A novel anodic catalyst for direct methanol fuel cell (DMFC), carbon supported Pt–Ru–Ni–P nanoparticles, has been prepared by chemical reduction method by using NaH₂PO₂ as a reducing agent. One glassy carbon disc working electrode is used to test the catalytic performances of the homemade catalysts by cyclic voltammetric (CV), chronoamperometric (CA) and amperometric i–t measurements in a solution of 0.5 mol L^–1 H₂SO₄ and 0.5 mol L^–1 CH₃OH. The compositions, particle sizes and morphology of home‐made catalysts are evaluated by means of energy dispersive analysis of X‐ray (EDAX), X‐ray diffraction (XRD) and transmission electron micrographs (TEM), respectively. TEM images show that Pt–Ru–Ni–P nanoparticles have an even size distribution with an average diameter of less than 2 nm. The results of CV, CA and i–t curves indicate that the Pt–Ru–Ni–P/C catalyst shows significantly higher activity and stability for methanol electrooxidation due to the presence of non‐metal phosphorus in comparison to Pt–Ru–Ni/C one. All experimental results indicate that the addition of non‐metallic phosphorus into the Pt–Ru–Ni/C catalyst has definite value of research and practical application for enhancing the performance of DMFC.     

Intermolecular Interactions Between Methanol/Water Molecules and Nafion™ Membrane: An Infrared Spectroscopy Study

The intermolecular interactions between methanol/water and Nafion™ membranes have been investigated using IR spectroscopy. The evolution of IR spectra of the Nafion™ membranes, immersed in various concentrations of methanol solution depends strongly on the methanol concentration. The O–H bending vibration modes at 1,636, 1,660 and 1,672 cm^–1 associated with the hydrogen bonding of (H₃O⁺…SO₃^–) as well as (CH₃OH₂⁺…SO₃^–), and at 1,702, 1,717 and 1,711–1,736 cm^–1 associated with the hydrogen bonding of (CF₂…H–O–CH₃), (CF₂…H–OH), (CF₂…⁺H₃O) and (CF₂…H–OSO₂^–) were observed. The vibration mode of (CF₂…H–O) was found to be appearing obviously at 3,821–3,900 cm^–1 when the Nafion™ membrane was immersed in the methanol solution with concentration higher than 6 M. On the other hand, the wavenumber of the O–H stretching peak increases with an increase in the methanol concentration. Results of IR spectra revealed that the methanol molecules show better capability to penetrate into the hydrophobic domain of the Nafion™ membrane than water. The intermolecular interaction between the hydrophobic domains of Nafion™ and methanol molecules becomes more observable at a higher methanol concentration.     

Microcrystalline-cellulose hydrolysis with concentrated sulphuric acid

The effects of temperature (25–40°C), H₂SO₄ concentration (31–70% (w/v)) and the acid/substrate relationship (1–5 cm³ of H₂SO₄ per g⁻¹ of cellulose) on the solubilization rate of microcrystalline cellulose and on the glucose production rate have been analysed. The solubilization process was by determining reducing groups present in solution. For acid/substrate relationships of more than 1 cm³ g⁻¹ and H₂SO₄ concentrations of greater than 62% (w/v), the acid promoted the total solubilization of the cellulose in the form of chains with a low degree of polymerization within 4 h. The solubilization demonstrated zero-order kinetics in which the specific rate and time of total solubilization are a function of the variables in operation. Glucose was produced according to a mechanism of two consecutive first-order pseudo-homogeneous reactions. The values of the kinetic constants k₁ and k₂ have been correlated with temperature, the H₂SO₄ concentration and the acid/substrate relationship.     

Application of insoluble cellulose xanthate for the removal of heavy metals from aqueous solution

Insoluble cellulose xanthate (ICX), O-alkyl dithiocarbonate of cellulose, was synthesized and used for the removal of heavy metal ions from aqueous solutions. ICX possessed carbon disulfide (CS₂) as a functional group, which was obtained by esterification of the hydroxyl group on cellulose polymer matrix with CS₂. CS₂ could form complexes with divalent transition metal ions, and the resulting ICX-metal complex was water-insoluble and settled easily. The optimum composition for ICX synthesis was cellulose/NaOH/CS₂=1: 2: 2.3 in mole base, which showed the highest removal capacity. The selectivity and binding capacity of ICX for heavy metals were in the order of Pb²⁺> Cd²⁺> Ni²⁺ and Cd²⁺> Pb²⁺> Ni²⁺, respectively. More than 90 % of the initial amount of heavy metals was removed within 30 min. The optimum pH was neutral or slightly alkaline, and more than 40 % of initial heavy metals was removed even in the acidic range of pH 2 to 3.     

Cationic starch iodophores

Cross‐linked cationic starches N‐(2‐hydroxyl)propyl‐3‐trimethyl ammonium starch chloride (CQS chloride), N‐(2‐hydroxyl)propyl‐3‐trimethyl ammonium starch iodide (CQS iodide), and N‐(2‐hydroxyl)propyl‐3‐trimethyl ammonium starch iodide–iodine (CQS triiodide) with the degree of substitution (DS) according to cationic groups from 0.04 to 0.62, as well as cross‐linked starch–iodine complexes were synthesized and tested as potential antibacterial agents. Cationic starch iodine derivatives were obtained during ion exchange reaction between CQS chloride and iodide or iodide–iodine anions in aqueous solutions. CQS_DS≤0.3 chloride can form several types of iodine complexes, such as the blue amylose–iodine inclusion complex and ionic CQS⁺I^?·(I₂)_m complex (m ≥ 1). The antibacterial activity of modified starches–iodine samples against different pathogenic bacterial cultures and contaminated water microorganisms was evaluated. CQS chloride and CQS iodide were found to be bacteriostatic. A strong antibacterial activity was characteristic of CQS triiodides in which molecular iodine is present in both ionic and inclusion complexes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Grafting of a styrene–acrylonitrile binary monomer mixture onto cellulose extracted from pine needles

In an attempt to develop new reactive membrane materials, we graft‐copolymerized styrene (Sty) and acrylonitrile (AN) onto cellulose extracted from pine needles by a chemical initiation method. The optimum grafting reaction conditions for Sty onto cellulose were earlier evaluated as [Sty] = 656.25 mmol/L and [potassium persulfate–ferrous ammonium sulfate] = 146.3:12.75mmol/L in 20 mL of H₂O with a reaction time of 3 h and a reaction temperature of 60°C for 1 g of cellulose. Under these conditions, Sty was graft‐copolymerized with AN at five different concentrations of the latter. Grafting parameters and different rates of concentration were evaluated. The effects of additives such as ZnCl₂, LiNO₃, and Cu(NO)₃ were studied at the best comonomer concentration of Sty–AN. In the presence of ZnCl₂, Sty–AN graft‐copolymerized in an alternate way, thus, making it evident that ZnCl₂ coordinated to form a “complexomer,” or complex of monomers [Sty^?AN⁺…ZnCl₂], of two monomers. Evidence of the structural characteristics of grafted chains were provided by characterization with elemental analysis, thermal analysis, and Fourier transform infrared spectroscopy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2000–2007, 2002     

Synthesis and characterisation of the first examples of four-membered ring ruthenalactam complexes

Reaction of the complexes [RuCl₂(PPh₃)L] (L = η⁶-p-cymene or η⁶-hexamethylbenzene) with N-cyanoacetylurethane [NCCH₂C(O)NHCO₂Et] and tertiary amine base in refluxing methanol gives the first examples of mononuclear complexes containing the four-membered ruthenalactam ring, Ru–C–C(O)–N. The complexes were characterised by ¹H and ³¹P{¹H} NMR spectroscopy and ESI mass spectrometry. A single-crystal X-ray diffraction study on the p-cymene complex showed the four-membered ruthenalactam ring to be planar.     

Radiation-induced graft polymerization of 4-vinyl pyridine to styrene–butadiene–styrene triblock copolymer

The radiation-induced graft polymerization of 4-vinyl pyridine to styrene–butadiene–styrene triblock copolymer (SBS) was investigated. Relations between the rate of grafting and the dose rate when SBS was irradiated in 4-vinyl pyridine–methanol solution, and between the rate of grafting and 4-vinyl pyridine concentration of 4-vinyl pyridine–methanol solution have been investigated. An experiment that had been carried out on SBS immersed in various 4-vinyl pyridine concentration of 4-vinyl pyridine–methanol solutions showed that the extent of swelling of SBS by the various 4-vinyl pyridine–methanol solutions increased with increasing 4-vinyl pyridine concentration. The largest rate was found at 20 vol % 4-vinyl pyridine–methanol solution. The rate was smaller at the volume percent of 4-vinyl pyridine higher or lower than 20 vol %. On the assumption that the theory of homogeneous homopolymerization could be applied to this grafting reaction, the value of k_p²/k_t was obtained, where k_p and k_t are the propagation and termination constant, respectively. The value of k_p²/k_t greatly decreased with increasing adsorbed concentration of vinyl pyridine–methanol solution. This decrease of k_p²/k_t was explained by the fact that 4-vinyl pyridine and methanol absorbed in SBS acted as a plasticizer which increased the molecular motion of the polymer. The solvent effect on the graft polymerization was also investigated. The result was explained by solubility parameter. When the chosen solvent had better solubility with the polymer, the degree of grafting was smaller. That was connected with the extent of the polymer chain mobility.     

Reaction kinetics modeling and thermal properties of epoxy–amines as measured by modulated‐temperature DSC. I. Linear step‐growth polymerization of DGEBA + aniline

A mechanistic approach including both reactive and nonreactive complexes can successfully simulate both nonreversing (NR) heat flow and heat capacity (C_p) signals from modulated‐temperature DSC in isothermal and nonisothermal reaction conditions for different mixtures of diglycidyl ether of bisphenol A + aniline. The reaction of the primary amine with an epoxy–amine complex initiates cure (E_1A1 = 80 kJ mol^?1), whereas the reactions of the primary amine (E_1OH = 48 kJ mol^?1) and secondary amine (E_2OH = 48 kJ mol^?1) with an epoxy–hydroxyl complex are rate determining from about 2% epoxy conversion on. The reliability of the proposed mechanistic model was verified by experimental concentration profiles from Raman spectroscopy. When cure temperatures are chosen inside or below the full cure glass‐transition region, vitrification takes place partially or completely, respectively, as can be concluded from the magnitude of the stepwise decrease in C_p. The effect of the epoxy conversion (x) and mixture composition on thermal properties such as the glass‐transition temperature (T_g), the change in heat capacity at T_g [ΔC_p(T_g)], and the width of the glass transition region (ΔT_g) are considered. The Couchman relationship, in which only T_g and ΔC_p(T_g) of both the unreacted and the fully reacted systems are needed, was evaluated to predict the T_g– x relation by using simulated concentration profiles. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91:2798–2813, 2004