Reactivity,chemical structure,and molecular mobility of urea–formaldehyde adhesives synthesized under different conditions using FTIR and solid‐state 13C CP/MAS NMR spectroscopy

This study was conducted to investigate the effects of reaction pH condition and hardener type on the reactivity, chemical structure, and molecular mobility of urea–formaldehyde (UF) resins. Three different reaction pH conditions, such as alkaline (7.5), weak acid (4.5), and strong acid (1.0), were used to synthesize UF resins, which were cured by adding four different hardeners (ammonium chloride, ammonium sulfate, ammonium citrate, and zinc nitrate) to measure gel time as the reactivity. FTIR and ¹³C‐NMR spectroscopies were used to study the chemical structure of the resin prepared under three different reaction pH conditions. The gel time of UF resins decreased with an increase in the amount of ammonium chloride, ammonium sulfate, and ammonium citrate added in the resins, whereas the gel time increased when zinc nitrate was added. Both FTIR and ¹³C‐NMR spectroscopies showed that the strong reaction pH condition produced uronic structures in UF resin, whereas both alkaline and weak‐acid conditions produced quite similar chemical species in the resins. The proton rotating‐frame spin–lattice relaxation time (T_1ρH) decreased with a decrease in the reaction pH of UF resin. This result indicates that the molecular mobility of UF resin increases with a decrease in the reaction pH used during its synthesis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2677–2687, 2003     

Continuous lipase‐catalyzed synthesis of hexyl laurate in a packed‐bed reactor: optimization of the reaction conditions in a solvent‐free system

BACKGROUND: Hexyl laurate has been applied widely in cosmetic industries and is synthesized by chemical methods with problems of cost, environmental pollution, and by‐products. In this study, Lipozyme^® IM77 (from Rhizomucor miehei) was used to catalyze the direct‐esterification of hexanol and lauric acid in a solvent‐free system by utilizing a continuous packed‐bed reactor, wherein the aforementioned difficulties could be overcome. Response surface methodology (RSM) and three‐level‐three‐factor Box‐Behnken design were employed to evaluate the effects of synthesis parameters, such as reaction temperature (45–65 °C), mixture flow rate (0.25–0.75 mL min^?1) and concentration of lauric acid (100–300 mmol L^?1) on the production rate (µmol min^?1) of hexyl laurate by direct esterification. RESULTS: The production rate was affected significantly by the mixture flow rate and lauric acid concentration. On the basis of ridge‐max analysis, the optimum synthesis conditions for hexyl laurate were as follows: 81.58 ± 1.76 µmol min^?1 at 55 °C, 0.5 mL min^?1 flow rate and 0.3 mol L^?1 lauric acid. CONCLUSION: The lipase‐catalyzed synthesis of hexyl laurate by Lipozyme^® IM‐77 in a continuous packed‐bed bioreactor and solvent‐free system was successfully developed; optimization of the reaction parameters was obtained by Box–Behnken design and RSM. Copyright © 2008 Society of Chemical Industry     

Water Solvent Method for Esterification and Amide Formation between Acid Chlorides and Alcohols Promoted by Combined Catalytic Amines: Synergy between N‐Methylimidazole and N,N,N′,N′‐Tetramethylethylenediamine (TMEDA)

An efficient method for esterification between acid chlorides and alcohols in water as solvent has been developed by combining the catalytic amines, N‐methylimidazole and N,N,N′,N′‐tetramethylethylenediamine (TMEDA). The present Schotten–Baumann‐type reaction was performed by maintaining the pH at around 11.5 using a pH controller to prevent the decomposition of acid chlorides and/or esters and to facilitate the condensation. The choice of catalysts (0.1 equiv.) was crucial: the combined use of N‐methylimidazole and TMEDA exhibited a dramatic synergistic effect. The catalytic amines have two different roles: (i) N‐methylimidazole forms highly reactive ammonium intermediates with acid chlorides and (ii) TMEDA acts as an effective HCl binder. The production of these intermediates was rationally supported by a careful ¹H NMR monitoring study. Related amide formation was also achieved between acid chlorides and primary or secondary amines, including less nucleophilic or water‐soluble amines such as 2‐(or 4‐)chloroaniline, the Weinreb N‐methoxyamine, and 2,2‐dimethoxyethanamine.     

Kinetics of esterification of palmitic acid with isopropanol using p‐toluene sulfonic acid and zinc ethanoate supported over silica gel as catalysts

Kinetic data on the esterification of palmitic acid with isopropanol were obtained using homogeneous (para‐toluene sulfonic acid, p‐TSA) and heterogeneous (zinc ethanoate coated on silica gel, ZnA/SG) catalysts in a batch reactor. The ZnA/SG catalyst was prepared using a sol–gel technique. The esterification reaction was studied at different reaction temperatures (373–443 K), initial reactants molar ratio (1–5), catalyst loading (1–5 gcat dm^?3) and water concentration in feed (0–15 vol%). A power law rate equation was used for homogeneous kinetics analysis. The Langmuir Hinshelwood Hougen Watson (LHHW) model was used for heterogeneous kinetics. The kinetic parameters of both models were obtained using Polymath software. The reaction parameters were used to obtain simulated values of conversion for both catalytic systems. The simulated values were compared with the experimental values and were in good agreement. Copyright © 2004 Society of Chemical Industry     

Esterification of Renewable Levulinic Acid to n‐Butyl Levulinate over Modified H‐ZSM‐5

The synthesis of n‐butyl levulinate, one of the most important biodiesel additives, by catalytic esterification of biomass‐derived levulinic acid (LA) with n‐butanol over modified H‐ZSM‐5 (micro/meso‐HZ‐5) in a closed‐batch system is reported for the first time. The optimization of the reaction conditions such as the reactant molar ratio, the catalyst loading, the reaction time and the temperature was performed in view to maximize the yield of n‐butyl levulinate. Micro/meso‐HZ‐5 was found to be the most efficient catalyst, with 98 % yield of n‐butyl levulinate and a reusability for six cycles, which is higher than reported in the literature. A possible catalytic mechanism for the esterification reaction is also proposed. A second‐order pseudo‐homogeneous model with R² > 0.97 confirmed that the esterification reaction is performed in the kinetic regime due to the high activation energy of 23.84 kJ mol^?1.     

Well‐defined polymers containing 1,3‐dichloro‐tetra‐n‐butyl‐distannoxane moiety: Synthesis,mechanism, and applications in catalysis

A series of well‐defined different chain lengths polymers, which contain the organometallic 1,3‐dichloro‐tetra‐n‐butyl‐distannoxane core in the main chain, was obtained in one‐pot via a novel 1,3‐dichloro‐tetra‐n‐butyl‐distannoxane (complex A )/azobisisobutyronitrile (AIBN) initiating system used in reverse atom transfer radical polymerization of styrene in different concentrations. The introduction of organotin complex A was supported by ¹H‐NMR, ¹³C–NMR, and the Inductive Coupled Plasma Emission Spectrometer analysis of the organotin‐containing polymer. Moreover, the mechanism of polymerization was investigated by changing the ratio of complex A to AIBN. It was concluded that the complex A not only acted as an important part of the initiator system but also introduced the functional organometallic group into the polymer chain. Additionally, the organotin‐containing polymer could be used as catalyst for esterification, and the reaction products' conversion could reach high up to 99% and does not decrease after four successive cycles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Polymer gel electrolytes prepared from P(EG‐co‐PG) and their nanocomposites using organically modified montmorillonite

Polymer gel electrolytes were prepared by thermal crosslinking reaction of a series of acrylic end‐capped poly(ethylene glycol) and poly(propylene glycol) [P(EG‐co‐PG)] having various geometries and molecular weights. Acrylic end‐capped prepolymers were prepared by the esterification of low molecular weight (M_n: 1900–5000) P(EG‐co‐PG) with acrylic acid. The linear increase in the ionic conductivity of polymer gel electrolyte films was observed with increasing temperature. The increase in the conductivity was also monitored by increasing the molecular weight of precursor polymer. Nanocomposite electrolytes were prepared by the addition of 5 wt % of organically modified layered silicate (montmorillonite) into the gel polymer electrolytes. The enhancement of the ionic conductivity as well as mechanical properties was observed in the nanocomposite systems. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 894–899, 2004     

Thermal decomposition kinetics of thermotropic copolyesters made from trans‐p‐hydroxycinnamic acid and p‐hydroxybenzoic acid

A series of thermotropic copolyesters were synthesized by direct thermal melt polycondensation of p‐acetoxybenzoic acid (PHB) with trans‐p‐acetoxycinnamic acid (PHC). The dynamic thermogravimetric kinetics of the copolyesters in nitrogen were analyzed by four single heating‐rate techniques and three multiple heating‐rate techniques. The effects of the heating rate, copolyester composition, degradation stage, and the calculating techniques on the thermostability and degradation kinetic parameters of the copolyesters are systematically discussed. The four single heating‐rate techniques used in this work include Friedman, Freeman–Carroll, Chang, and the second Kissinger techniques, whereas the three multiple heating‐rate techniques are the first Kissinger, Kim–Park, and Flynn–Wall techniques. The decomposition temperature of the copolyesters increases monotonically with increasing PHB content from 40 to 60 mol %, whereas their activation energy exhibits a maximal value at the PHB content of 50 mol %. The decomposition temperature, activation energy, the order, and the frequency factor of the degradation reaction for the thermotropic copolyester with PHB/PHC feed ratio of 50/50 mol % were determined to be 374°C, 408 kJ/mol, 7.2, and 1.25 × 10²⁹ min^?1, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 445–454, 2004     

Application of metal triflate catalysts for the trans-esterification of Jatropha curcas L. oil with methanol and higher alcohols

This paper describes an experimental study on the application of metal triflate salts for the (trans‐) esterification of fatty esters (triolein, methyl oleate, methyl linoleate), fatty acid (oleic acid), as well as Jatropha curcas L. oil with methanol and higher alcohols (ethanol, n‐propanol, iso‐propanol, iso‐butanol, tert‐butanol). The effect of the metal type (scandium, bismuth, aluminium, lanthanum, copper, zinc) and process conditions on reaction performance were evaluated. Highest conversions were obtained with Al(OTf)₃. Reaction of triolein with methanol gave 99 mol% conversion at 165 °C for 1 h and the main product was the methyl ester. In addition, partial methoxylation of the carbon–carbon double bonds in the fatty acid chains was observed, though their fraction in the mixture was less than 20 mol%. The trans‐esterification reaction was also successfully performed using higher alcohols, giving >95 % conversions for ethanol, n‐propanol, iso‐propanol and iso‐butanol, whereas tert‐butanol was not reactive. For the reaction of oleic acid with methanol, quantitative esterification, partial methoxylation of the carbon–carbon double bonds and the formation of small amounts of a lactone was observed. The methodology using Al(OTf)₃ was successfully performed on the trans‐esterification reaction of JO (FFA content of 2.1 wt%) with various alcohols. Key properties (viscosity, pour point and cloud points) of the (branched) Jatropha esters were determined. The best cold‐flow properties were obtained for the iso‐propyl esters of JO, with cloud point and pour point of ?3 and ?24 °C, respectively.     

Lipase‐catalyzed esterification of cinnamic acid and oleyl alcohol in organic solvent media

The esterification of cinnamic acid (CA) and oleyl alcohol (OA) in organic solvent media by immobilized lipase Novozym 435 was optimized in terms of selected parameters, including the logarithm of the 1‐octanol/water partition coefficient of the organic solvent (log P, 0.29–4.5), initial water activity (a_w, 0.05–0.75), agitation speed (0–200 rpm), temperature (35–65 °C) and ratio of substrates (CA/OA, 1.0:0.5–1.0:6.0). The results showed that the more hydrophobic solvent mixtures and lower initial a_w values resulted in a higher enzymatic activity and bioconversion yield. The most appropriate solvent medium and initial a_w value was the mixture of iso‐octane/2‐butanone (85:15, v/v) and 0.05, respectively. The results also showed that an agitation speed of 150 rpm and a reaction temperature of 55 °C were optimal for the reaction system. The activation energy (E_a) of the esterification reaction was calculated as 43.6 kJ mol^?1. The optimal ratio of CA to OA was 1.0:6.0, with the absence of any inhibition by OA. Using the optimized conditions, the maximum enzymatic activity was 390.3 nmol g^?1 min^?1, with a bioconversion yield of 100% after 12 days of reaction. In addition, the electrospray ionization‐mass spectroscopy analysis confirmed that the major end product of the esterification reaction was oleyl cinnamate. Copyright © 2005 Society of Chemical Industry     

Study on the Synthesis of n‐Butyl Acetate by Catalytic Rectification

With Hβ zeolite as the catalyst and θ rings as the fillings, the technological process of synthesizing n‐butyl acetate with acetic acid and n‐butanol in a Φ 30 mm and 2 m tall catalytic rectifying column was studied. The influence of factors such as catalyst loading height, material feed site, reflux ratio and feed rate on the esterification reaction and the rectification effect was investigated. The study results suggested that the appropriate conditions of n‐butyl acetate synthesis by catalytic rectification include: The height ratio of the rectifying section, the reaction section and the stripping section is 1:1:1; acetic acid and n‐butanol are fed in upside and downside of the reaction section, respectively; the reflux ratio is 2.5; the liquid hourly space velocity of n‐butanol is 0.64 h^–1. Under these conditions, the mass fraction of n‐butyl acetate in the column bottom is 98.64 %, and the total yield of n‐butyl acetate is 91.5 %.     

Lipase‐catalyzed synthesis of butyl esters by direct esterification in solvent‐free system

BACKGROUND: Reactions performed under solvent‐free conditions give processes that are environmentally friendly, since most solvents are polluting agents. In this work, the performance of Candida rugosa lipae (CRL) immobilized on styrene‐divinylbenzene (STY‐DVB) or controlled pore silica (CPS), and the commercial lipase Novozym 435, was evaluated for the synthesis of butyl esters in solvent–free systems (SFS). A 2² full factorial design was used to study the influence of the organic acid chain length and the biocatalyst concentration on the esterification performance. RESULTS: When CRL on STY‐DVB was used, the ester formation was influenced by both variables and their interaction. The reaction conversion was higher (63%) using 10% of immobilized system and lauric acid, corresponding to a productivity of 3.62 g L^?1 h^?1 For CRL on CPS, only the effect of biocatalyst concentration was significant, and the highest yield was attained using 20% of immobilized system and caprilic acid. In the case of Novozym 435, the highest yield (49%) was obtained using butyric acid as acyl donor at 15% of immobilized lipase. CONCLUSION: The results allowed better understanding of the influence of important parameters in this environmentally friendly process, which also has the process advantage of a higher volumetric productivity when compared with a solvent system. Copyright © 2007 Society of Chemical Industry     

Synthesis and characterization of new polyureas based on 4‐(4′‐aminophenyl)urazole and various diisocyanates

4‐(4′‐Aminophenyl)urazole (AmPU) was prepared from 4‐nitrobenzoic acid in six steps. The reaction of monomer AmPU with n‐isopropylisocyanate was performed in N,N‐dimethylacetamide solutions at different ratios, and the resulting disubstituted and trisubstituted urea derivatives were obtained in high yields and were finally used as models for polymerization reactions. The step‐growth polymerization reactions of AmPU with hexamethylene diisocyanate, isophorone diisocyanate, and toluene‐2,4‐diisocyanate were performed in N‐methylpyrrolidone solutions in the presence of pyridine as a catalyst. The resulting novel polyureas had inherent viscosities of 0.11–0.18 dL/g in dimethylformamide at 25°C. These polyureas were characterized with IR, ¹H‐NMR, elemental analysis, and thermogravimetric analysis. Some physical properties and structural characterization of these novel polyureas are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2692–2700, 2003     

Synthesis and photoinitiating activity study of polymeric photoinitiators bearing BP moiety based on hyperbranched poly(ester‐amine) via thiol‐ene click reaction

A series of polymeric photoinitiators (BP‐HPEAs) bearing BP moiety based on hyperbranched poly(ester‐amine) were synthesized via the thiol‐ene click reaction of 3‐(4‐benzoylphenoxy)propyl 2‐mercaptoacetate (BPPM) with acrylated HPEA. BPPM was obtained by the esterification of (4‐(3‐hydroxypropoxy) phenyl) phenyl methanone (HPPM) with mercaptoacetic acid in the presence of p‐toluene sulphonic acid as a catalyst. HPEA was prepared through Michael addition of piperazine with tri(hydroxymethyl)propane triacrylate. Their molecular structures were confirmed by the ¹H NMR, ¹³C NMR, and FTIR analysis. The UV–vis spectrum analysis results showed that BP‐HPEAs exhibit the stronger n–π* absorption at ～ 340 nm with over two times higher molar extinction coefficients than BP at the concentration of 1.00 × 10^?3M. The photoinitiating activity study showed that the maximum photopolymerization rates of 1,6‐hexanediol diacrylate initiated by BP‐HPEAs in the absence of coinitiator were obtained by two times higher than that by BP in the presence of triethylamine as a coinitiator. Moreover, the excellent miscibility of BP‐HPEAs with the commercial bisphenol A epoxy diacrylate was achieved according to the T_s/T_g ratios of over 9.0 from DMTA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of poly(methacrylates) containing spiroacetal and norbornene moieties in side chain

A four‐step synthetic strategy was applied to achieve novel methacrylic monomers. 5‐Norbornene‐2,2‐dimethanol was prepared from a Diels–Alder reaction of cyclopentadiene and acrolein, followed by the treatment of the adduct with an HCHO/KOH/MeOH solution. The resulting 1,3‐diol (1) was then acetalized with different aromatic aldehydes having OH groups on the ring to produce four spiroacetal derivatives. The reaction of methacryloyl chloride with the phenolic derivatives led to four new methacrylic monomers that were identified spectrochemically (mass, FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopy). Free radical solution polymerization was used to prepare novel spiroacetal–norbornene containing polymethacrylates, which were characterized by FTIR and ¹H‐NMR spectroscopy and differential scanning calorimetry and thermogravimetric thermal analysis. Gel permeation chromatography was performed to determine molecular weight averages and polydispersity. The polymethacrylate having naphthalenic nuclei was recognized to be the highest molecular weight polymer (M̄_n = 12144, η_inh = 0.80 dL/g) with the highest thermal stability. All the polymers showed good solubility in a variety of common organic solvents. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 30–38, 2000     

Antibacterial and biodegradable properties of polyhydroxyalkanoates grafted with chitosan and chitooligosaccharides via ozone treatment

Acrylic acid was grafted to ozone‐treated poly(3‐hydroxybutyric acid) (PHB) and poly(3‐hydroxybutyric acid‐co‐3‐hydroxyvaleric acid) (PHBV) membranes. The resulting membranes were further grafted with chitosan (CS) or chitooligosaccharide (COS) via esterification. These CS‐ or COS‐grafted membranes showed antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, methicilin‐resistant Staphylococcus aureus (MRSA), and S. aureus. The antibacterial activity to E. coli was the highest, whereas the antibacterial activity to MRSA was the lowest among these four bacteria tested. Acrylic acid grafting can increase the biodegradability with Alcaligens faecalis, whereas CS and COS grafting can reduce the biodegradability. In addition, CS‐grafted PHBV membrane showed higher antibacterial activity and lower biodegradability than COS‐grafted PHBV membrane. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2797–2803, 2003     

Properties of poly(AAc‐co‐HPMA‐cl‐EGDMA) hydrogel‐bound lipase of Pseudomonas aeruginosa MTCC‐4713 and its use in synthesis of methyl acrylate

Microbial lipases (E.C. 3.1.1.3) are preferred biocatalysts for the synthesis of esters in organic solvents. Various extracellular thermoalkaliphilic lipases have been reported from Pseudomonas sp. In the present study, a purified alkaline thermoalkalophilic extracellular lipase of Pseudomonas aeruginosa MTCC‐4713 was efficiently immobilized onto a synthetic poly(AAc‐co‐HPMA‐cl‐EGDMA) hydrogel by adsorption and the bound lipase was evaluated for its hydrolytic potential towards various p‐nitrophenyl acyl esters varying in their C‐chain lengths. The bound lipase showed optimal hydrolytic activity towards p‐nitrophenyl palmitate (p‐NPP) at pH 8.5 and temperature 45°C. The hydrolytic activity of the hydrogel‐bound lipase was markedly enhanced by the presence of Hg²⁺, Fe³⁺, and NH salt ions in that order. The hydrogel‐immobilized lipase (25 mg) was used to perform esterification in various n‐alkane(s) that resulted in ～ 84.9 mM of methyl acrylate at 45°C in n‐heptane under shaking (120 rpm) after 6 h, when methanol and acrylic acid were used in a ratio of 100 mM:100 mM, respectively. Addition of a molecular sieve (3Å × 1.5 mm) to the reaction system at a concentration of 100 mg/reaction vol (1 mL) resulted in a moderate enhancement in conversion of reactants into methyl acrylate (85.6 mM). During the repetitive esterification under optimum conditions, the hydrogel‐bound lipase produced 71.3 mM of ester after 10th cycle of reuse. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 183–191, 2007     

Structural characterization of oligomers from the polycondensation of citric acid with ethylene glycol and long‐chain aliphatic alcohols

The structural characterization of polyesters of citric acid (CA) with ethylene glycol and long‐chain aliphatic alcohols (ROH), prepared by the composition of the reaction mixture being adjusted slightly away from stoichiometric equivalence, was performed with ¹H‐ and ¹³C‐NMR spectroscopy. The aliphatic alcohols employed were 1‐decanol, 1‐dodecanol, and 1‐octadecanol. The ¹³C‐NMR carbonyl region presented four groups of signals, two corresponding to the ester groups and two corresponding to the acid groups. However, symmetric and asymmetric groups of CA moieties were identified in the ¹³C‐NMR spectra. The ester yield from ROH decreased as the number of carbon atoms in the alcohols increased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 302–306, 2003     

Synthesis and characterization of thiol‐terminated poly(ethylene oxide) for chemisorption to gold surface

Thiol‐terminated poly(ethylene oxide) (PEO) was synthesized using two different approaches: esterification of terminal hydroxyl groups with mercaptoacetic acid and amidation using N‐hydroxysuccinimidyl PEO (NHS–PEO) and cysteine. The reaction of hydroxyl‐terminated PEO with mercaptoacetic acid was carried out in boiling toluene. Different thiolated PEOs, including linear PEOs of varying molecular weights and end‐group types, and star‐type PEOs were synthesized. Nuclear magnetic resonance and infrared spectroscopy were used to characterize the products. The reaction kinetics were also briefly investigated. Gel permeation chromatography was used to investigate the relative amounts of the mono‐ and disubstituted products in the α,ω‐dihydroxy PEOs. NHS–PEO was used both to attach terminal thiol groups via reaction with cysteine and to conjugate other amino acids (and potentially any amino‐containing molecule) to PEO. Reactions using NHS–PEO were carried out at room temperature in water. The chemisorption of these thiolated PEOs to gold was expected to yield surfaces resistant to biofouling, in particular to unwanted protein adsorption. Chemisorption of amino acid–, peptide‐, or protein‐terminated PEOs in addition may yield surfaces having specific biological activity. Work on these aspects will be reported elsewhere. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 594–607, 2003     

Investigation of microstructure of 4‐vinyl pyridine–methacylonitrile copolymers by NMR spectroscopy

4‐Vinyl pyridine–methacrylonitrile (V/M) copolymers of different composition were prepared by bulk polymerization using benzoyl peroxide as an initiator. The copolymer composition was determined from quantitative ¹³C{¹H}‐NMR spectra. The reactivity ratios for V/M copolymer obtained from a linear Kelen‐Tudos method (KT) and nonlinear error‐in‐variables method (EVM) are r_V = 0.79 ± 0.12, r_M = 0.38 ± 0.09 and r_V = 0.79 ± 0.13, r_M = 0.38 ± 0.07, respectively. The complete spectral assignment in term of compositional and configurational sequences of these copolymers were done with the help of distortionless enhancement by polarization transfer (DEPT), two‐dimensional heteronuclear single quantum coherence spectroscopy (HSQC). Total correlated spectroscopy (TOCSY) experiment was used to assign the various three‐bond ¹H‐¹H couplings in the V/M copolymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 3232–3238, 2003