Synthesis and characterization of a drug‐delivery system based on melamine‐modified poly(vinyl acetate‐co‐maleic anhydride) hydrogel

Three‐dimensional polymeric networks, which quickly swell by imbibing a large amount of water or deswell in response to changes in their external environment, are called hydrogels. These types of polymeric materials are good potential candidates for drug‐delivery systems. In this study, we first synthesized poly(vinyl acetate‐co‐maleic anhydride) by free‐radical copolymerization. Then, they were modified with different molar ratios of melamine to prepare hydrogels that could be used in drug‐delivery systems. The hydrogels were characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, differential scanning calorimetry, and scanning electron microscopy. In the second step, Ceftazidime antibiotic was loaded on selected hydrogels. The in vitro drug release was investigated and compared in three different media (HCl solution at pH = 3 and buffer solutions at pH 6.1and pH 8). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40389.     

Polymeric hydrogels obtained using a redox initiator: Application in Cu(II) ions removal from aqueous solutions

Poly(acrylic acid‐co‐acrylamide) hydrogels were prepared via free‐radical solution polymerization, crosslinked with ethylene‐glycol‐dimethacrylate, potassium persulfate/ammonium bisulfite as the initiator, and applied in the removal of Cu(II) ions from aqueous solutions. Molar ratios of acrylamide/acrylic acid moieties and the amount of crosslinking agent were varied to determine the swelling capacities of hydrogels and maximum metal uptake. Polymerization kinetics was investigated by ¹H‐NMR. Hydrogel physicochemical properties were characterized by nitrogen sorption measurements, elemental analysis, FTIR, and X‐ray photoelectron spectroscopy (XPS). Swelling results indicated that hydrogels were swollen up to 27,500%. Hydrogels showed equilibrium Cu(II) adsorption capacities of 211.7 mg g^?1 and fast kinetics (～20 min). Langmuir isotherm fitted adsorption equilibrium data. FTIR and XPS results helped in elucidating the presence of monodentate copper complex on the surface of hydrogels. A simple synthesis route of hydrogels using the redox initiator suggests the potential application in the removal of toxic metals from aqueous streams. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39933.     

Synthesis,characterization, and in vitro biocompatibility study of novel disulfide cross‐linked hydrogels based on poly(amic acid)

In this study, novel disulfide cross‐linked hydrogels were designed and synthesized. First, ethylenediaminetetraacetic dianhydride reacted with butanediamine and amino‐terminated polyethylene glycol via N‐acylation reaction to give biocompatible poly(amic acid) (PAA) with pendant carboxyl groups; then, the amino groups of cystamine reacted with carboxyl groups of PAA to generate disulfide cross‐linked network polymer (PAA‐SS). Fourier transform infrared spectroscopy, ¹H nuclear magnetic resonance imaging, gel permeation chromatography with multiangle laser light scattering, potentiometric titration, rheology, hydrolytic degradation, morphology, porosity, and in vitro biocompatibility studies were used to qualitatively and quantitatively characterize the obtained polymers. The results indicated that the equilibrium swelling ratio of the PAA‐SS decreased with the increase in Rm. The PAA‐SS provided good mechanical strength to maintain their integrity, and the storage modules (G′) of the hydrogels can be adjusted by Rm. The PAA‐SS presented co‐continuum pores, and the pore size correlated with the cross‐linking degree. The degradation of PAA‐SS could be controlled by regulating the concentration of dithiothreitol. Particularly, the PAA‐SS possessed an excellent biocompatibility, as the average proliferating rate of osteoblasts on PAA‐SS was appreciably higher than that on PAA and glass coverslips. In conclusion, the above obtained results demonstrate that the performance of the PAA‐SS outbalance and facilitate the application in biomedical region, particularly in bone tissue regeneration. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40930.     

Hydrogels from dextran and soybean oil by UV photo‐polymerization

In this work, hydrogels were synthesized by UV photo‐polymerization of hydrophilic dextran functionalized with acrylate groups (Dex‐A) and hydrophobic acrylate epoxidized soybean oil (AESO). The acrylation of dextran was accomplished by reacting dextran (M_w 70,000 g mol^?1) with acryloyl chloride and pyridine. The Dex‐A was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Five rigid hydrogels were prepared using the weight ratios of Dex‐A and AESO as 10/90, 20/80, 30/70, 40/60, and 50/50. The hydrogels were characterized by FTIR, thermal gravimetric analyses (TGA) and scanning electronic microscopy (SEM). The experimental results demonstrated that the swelling and release profiles of the Dex‐A/AESO hydrogels can be tailored by varying the ratio of Dex‐A and AESO thus varying the balance of hydrophilicity and hydrophobicity of the network structures and the crosslinking density. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41446.     

Synthesis of polyaminostyrene‐based and polyallylamine‐based sorbents for boron removal

Hydroxyalkyl derivatives of polyaminostyrene (PAS), polyallylamine (PAA), and polyethyleneimine (PEI) containing a 2,3‐dihydroxypropyl moiety with a high degree of modification were synthesized. The chemical structures of the polymer transformation products were characterized with elemental analysis, Fourier transform infrared spectroscopy, ¹H‐NMR spectroscopy, and ¹³C‐NMR spectroscopy in the solid state. PAS reacted with glycidol and formed poly[N‐(2,3‐dihydroxypropyl)aminostyrene] with a high degree of functionalization. PAA revealed primarily the graft polymerization of glycidol. In the case of PEI, primary amino groups allowed the formation of an N‐derivative of 3‐aminopropanediol‐1,2. The PAA‐based sorbent showed a high sorption capacity toward boron ions in both acidic and alkaline media. From the sorption isotherm data, the maximum sorption capacity of this sorbent at pH 4 was determined to be 3 mmol/g. The PAS‐based resin maintained a high capacity between pH 9 and 12; the optimum pH was 12. The sorption capacity was 1.7 mmol/g. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43939.     

Porous poly(ethylene glycol)–polyurethane hydrogels as potential biomaterials

We report the synthesis of porous poly(ethylene glycol)–polyurethane (PEG‐PU) hydrogels using PEG‐4000 as a soft segment and 4,4′‐methylenebis(cyclohexylisocyanate) as a hard segment. The degree of swelling in the hydrogels could be controlled by varying the amount of crosslinking agent, namely 1,2,6‐hexanetriol. Structural characterization of the hydrogels was performed using solid‐state ¹³C NMR and Fourier transform infrared spectroscopy. Wide‐angle X‐ray diffraction studies revealed the existence of crystalline domains of PEG and small‐angle X‐ray scattering studies showed the presence of lamellar microstructures. For generating a porous structure in the hydrogels, cryogenic treatment with lyophilization was used. Scanning electron microscopy and three‐dimensional micro‐computed tomography imaging of the hydrogels indicated the presence of interconnected pores. The mechanical strength of the hydrogels and xerogels was measured using dynamic mechanical analysis. The observed dynamic storage moduli (E′) for the equilibrium swollen and dry gels were found to be 0.15 and 4.2 MPa, respectively. Interestingly, the porous PEG‐PU xerogel also showed E′ of 5.6 MPa indicating a similar mechanical strength upon incorporating porosity into the gel matrix. Finally, preliminary cytocompatibility studies showed the ability of cells to proliferate in the hydrogels. These gels show promise for applications as scaffolds and implants in tissue engineering. © 2014 Society of Chemical Industry     

The sulfonation of poly(ether ether ketone) as investigated by two‐dimensional FTIR correlation spectroscopy

Fourier transform infrared and two‐dimensional correlation (2D‐COS) spectroscopies were used to follow the structural alteration occurring upon sulfonation of poly(ether ether ketone), in concentrated sulfuric acid at room temperature. With the help of high resolution and high sensitivity 2D‐COS, it was possible to locate the aromatic ring in which the substitution has taken place. Two new IR bands at 1288 and 1320 cm^?1 were attributed to substitution occurring on the aromatic ring flanked with two ether groups. Limited oxidation effects of concentrated sulfuric acid manifested itself by the production of new carbonyl species absorbing in the IR at 1720 and 1750 cm^?1 that were attributed to a fluorenone‐type structure and to ester groups. The 2D‐COS analysis showed that the band at 1470 cm^?1 is not only due to the new substitution by sulfone groups and can not be used in the determination of sulfonation degree. Instead, the intensity of the 1490 cm^?1 band, which can be attributed to skeletal ring vibration, was found to correlate well with the degree of sulfonation calculated from ¹H NMR spectroscopy. The infrared spectroscopy combined with 2D‐COS provides a fast and powerful method for qualitative polymer structure verification and help to establish the quantitative analysis. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41242.     

Rheological and thermal properties of saponified cassava starch‐g‐poly(acrylamide) superabsorbent polymers varying in grafting parameters and absorbency

Cassava starch‐graft‐poly(acrylamide) superabsorbent polymers (SAPs) with varying absorbencies were synthesized. Weight average molecular weight (M_w) of the hydrolyzed starch‐graft‐copolymers ranged from 1.6 × 10⁶ to 2.8 × 10⁶ g/mol, the largest being shown by the sample with highest percentage grafting. The storage (G′) and loss modulus (G″) of hydrogels were determined as a function of frequency. G″ was larger than G′ for the hydrogels with higher absorbencies and exhibited a liquid‐like behavior. However, hydrogels with lower absorbencies showed a reverse viscoelastic behavior. The viscosity of hydrogels determined using a Brookfield viscometer at different shear rates was found to be larger for the hydrogels with higher absorbencies. The melting temperature (T_m) and enthalpy change of fusion (ΔH_f) of the SAPs ranged from 149.7 to 177.7°C and 65 to 494.9 J/g, respectively and showed a positive correlation with grafting parameters and M_w. Heavy metal ion removal capacity of hydrogel followed the order Cu²⁺ > Pb²⁺ > Zn²⁺. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40368.     

pH‐ and temperature‐responsive IPN hydrogels based on soy protein and poly(N‐isopropylacrylamide‐co‐sodium acrylate)

pH‐ and temperature‐responsive interpenetrating polymer network (IPN) hydrogels based on soy protein and poly(N‐isopropylacrylamide‐co‐sodium acrylate) were successfully prepared. The structure and properties of the hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analyzer. The equilibrium and dynamic swelling/deswelling behaviors and the drug release properties of the hydrogels responding to pH and/or temperature were also studied in detail. The hydrogels have the porous honeycomb structures, good miscibility and thermal stability, and good pH‐ and temperature‐responsivity. The volume phase transition temperature of the hydrogels is ca. 40°C. Changing the soy protein or crosslinker content could be used to control the swelling behavior and water retention, and the hydrogels have the fastest deswelling rate in pH 1.2 buffer solutions at 45°C. Bovine serum albumin release from the hydrogels has the good pH and temperature dependence. The results show that the proposed IPN hydrogels may have potential applications in the field of biomedical materials such as in drug delivery systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39781.     

Smart carboxymethylchitosan hydrogels that have thermo‐ and pH‐responsive properties

Thermo‐responsive poly(N‐isopropylacrylamide) (poly(NIPAAm)) and pH‐responsive poly(N,N′‐diethylaminoethyl methacrylate) (poly(DEAEMA)) polymers were grafted to carboxymethylchitosan (CMC) via radical polymerization to form highly water swellable hydrogels with dual responsive properties. Ratios of CMC, NIPAAm to DEAEMA used in the reactions were finely adjusted such that the thermo and pH responsiveness of the hydrogels was retained. Scanning electron microscopy (SEM) indicated the formation of an internal porous structure for the swollen CMC hydrogels upon incorporation of poly(NIPAAm) and poly(DEAEMA). Effect of temperature and pH changes on water swelling properties of the hydrogels was investigated. It was found that the water swelling of the hydrogels was enhanced when the solution pH was under basic conditions (pH 11) or the temperature was below its lower critical solution temperature (LCST). These responsive properties can be used to regulate releasing rate of an entrapped drug from the hydrogels, a model drug, indomethacin was used to demonstrate the release. These smart and nontoxic CMC‐based hydrogels show great potential for use in controlled drug release applications with controllable on‐off switch properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41505.     

In vitro silver ion release kinetics from nanosilver/poly(vinyl alcohol) hydrogels synthesized by gamma irradiation

A nanosilver (nano‐Ag)/poly(vinyl alcohol) (PVA) hydrogel device was synthesized with γ irradiation because it is a highly suitable tool for enhanced nano‐Ag technologies and biocompatible controlled release formulations. The amount of the Ag⁺ ions released in vitro by the nano‐Ag/PVA hydrogel device was in the antimicrobial parts per million concentration range. The modeling of the Ag⁺ ion release kinetics with the elements of the drug‐delivery paradigm revealed the best fit solution (R² > 0.99) for the Kopcha and Makoid–Banakar's pharmacokinetic dissolution models. The term A/B, derived from the Kopcha model, indicated that the nano‐Ag/PVA hydrogel was mainly an Ag⁺‐ion diffusion‐controlled device. Makoid–Banakar's parameter and the short time approximated Ag⁺‐ion diffusion constant reflected the importance of the size of the Ag nanoparticles. However, it appeared that the cell oxidation potential of the Ag nanoparticles depended on the diffusion characteristics of the fluid penetrating into the Ag/PVA nanosystem. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40321.     

Cassava starch‐graft‐polymethacrylamide copolymers as flocculants and textile sizing agents

Cassava starch‐graft‐polymethacrylamide (PMAM) copolymers were synthesized by a free‐radical‐initiated polymerization reaction, and the products were tested for their efficiency as flocculants and textile sizing agents. The highest percentages of grafting and monomer conversion were 79.9 and 78.0%, respectively. The grafted starches were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction analysis, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. The average molecular weight of PMAM chains in the grafted starches ranged from 15.9 to 30.8 × 10⁵ g/mol. The grafted starches exhibited a higher peak viscosity and paste stability in comparison to the native starch (NS). Dynamic mechanical analysis showed that grafting provided fairly shear‐stable hydrogels, and the highest storage modulus obtained was 17,900 Pa compared to 1879 Pa for NS. The flocculation studies demonstrated the superiority of starch‐g‐PMAM over cassava starch and PMAM as an efficient flocculant. The tensile strength of cotton yarns sized with the starch‐grafted copolymer was significantly higher (104 MPa) compared to that sized with NS (34 MPa). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39810.     

Poly(ethylene glycol)‐containing cationic hydrogels with lipophilic character

Not much effort has been focused towards the development of hydrogels that swell in nonpolar solvents. We have synthesized a new set of polyelectrolyte hydrogels and demonstrated their ability to absorb a less‐polar or nonpolar organic solvent, as well as their ability to resist gel‐collapse in a predominantly nonpolar medium. The hydrogels were prepared by free radical polymerization of different molar ratios of poly(ethylene glycol) methyl ether acrylate and (3‐(methacryloylamino)propyl)‐trimethyl ammonium chloride as comonomers in an aqueous medium. Their swelling behavior in organic solvents was studied by varying the dielectric constant of the swelling medium including mixed‐solvent systems. Besides a high degree of swelling (up to 200 times) in polar solvents, some of the hydrogels also exhibited moderate swelling (up to 15 times) in less‐polar organic solvents. Hydrogels samples with high cationic content showed drastic change in swelling extent in some of the mixed‐solvent systems. It was also interesting to note that the retention of significant swelling in dimethyl sulphoxide–toluene mixture with even 90% toluene content for some compositions. These polyelectrolyte hydrogels with improved lipophilicity opens up greater opportunities for the development of even superior soft materials through proper structural optimizations that would successfully function for a wider range of solvents. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39873.     

Preparation of amphoteric N,O‐carboxymethyl hydroxypropyl chitosan by a two‐step reaction

A novel N,O‐carboxymethyl hydroxypropyl chitosan (HPCMS) derivative was prepared by a two‐step reaction. Water‐soluble hydroxypropyl chitosan (HPCS) with a degree of substitution of hydroxypropyl higher than 0.8 was first synthesized by the reaction of chitosan (CS) with propylene oxide (PO) with alkali as a catalyst. Then, amphoteric chitosan derivatives (HPCMS) with a degree of substitution of carboxymethyl ranging from 0.42 to 1.38 were prepared by the reaction of HPCS with chloroacetic acid in an aqueous solution with alkali as a catalyst. The structures of the polymers were characterized by Fourier transform infrared spectroscopy and NMR; this showed that the hydroxypropylation mainly occurred on the ? OH groups at the C‐6 of CS in the reaction of CS with PO. In the reaction of HPCS with chloroacetic acid, both the ? OH and ? NH₂ groups of HPCS were susceptible to the carboxymethylation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40460.     

Design of a probe based on poly(glycidyl methacrylate‐co‐vinylferrocene)‐coated Pt electrode for electrochemical detection of PTEN gene in PCR amplified samples from prostate tissues

In this study, a new probe based on immobilization of amino linked oligonucleotide (NH₂‐linked DNA) on poly(glycidyl methacrylate‐co‐vinylferrocene)‐coated Pt electrode was fabricated for the electrochemical detection of PTEN gene from human prostate tissues. The experimental parameters such as DNA immobilization time, DNA concentration, and target concentration were optimized. The selectivity of the NH₂‐linked DNA probe was assessed with mismatch (MM) and noncomplementary (NC) sequences. The applicability of the NH₂‐linked DNA probe to the PCR amplified samples correspond to PTEN gene from prostate tissues was evaluated. The immobilization of DNA on the copolymer was confirmed by FTIR, AFM, CV and DPV analysis. The PCR products were also identified by using agarose gel electrophoresis. The prepared probe indicated a linear range (10–100 μg mL^?1) with a detection limit (4.7 μg mL^?1) and a good selectivity of the NH₂‐linked DNA probe toward target DNA sequence. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40638.     

Facile synthesis of biocompatible polyglycerol hydrogel based on epichlorohydrin

A series of hydrophilic polyglycerol (PG) hydrogel was designed and synthesized via one pot with epichlorohydrin (ECH), H₂O, and NaOH as the starting materials. The equilibrium swelling ratios of PG hydrogels could be tuned by simply changing the feed amount of NaOH. The gels were characterized by carbon nuclear magnetic resonance (¹³C NMR) spectroscopy, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The As‐synthesized PG hydrogels showed temperature‐sensitive swelling behaviors. The results of MTT assay suggested that the PG hydrogels prepared by this novel synthesis method showed comparable cytocompatibility with the recognized poly(ethylene glycol) hydrogel. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43451.     

Preparation of antibacterial temperature‐sensitive silver‐nanocomposite hydrogels from N‐isopropylacrylamide with green tea

This article reports the temperature‐sensitive, green tea (GT)‐based silver‐nanocomposite hydrogels for bacterial growth inactivation. The temperature‐sensitive hydrogels were prepared via free‐radical polymerization using temperature‐sensitive N‐isopropylacrylamide (NIPAM) monomer with GT as the hydrogel matrix. The nanocomposite hydrogels were encapsulated with silver ions via swelling method, which was later reduced to silver nanoparticles using Azadirachta indica leaf extract. The temperature‐sensitive silver nanocomposite hydrogels were analyzed by using Fourier transforms infrared, UV–visible spectroscopy, differential scanning calorimetry–thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The prepared hydrogels exhibited higher phase volume transition temperature than the NIPAM. The inhibition zone study of the inactivation of bacteria on the developed hydrogels was carried out against Gram negative (Escherichia coli) and Gram positive (Staphylococcus aureus), which revealed that the prepared hydrogels are helpful for the inactivation of these bacteria due to the high stabilization of antibacterial properties of the silver nanoparticles. The developed hydrogels are promising for biomedical applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45739.     

Influence of chain length of diol on the swelling behavior of citric acid based pH sensitive polymeric hydrogels: A green approach

Synthesis of pH‐sensitive hydrogels of citric acid with varying diol units viz., 1,2 Ethane diol, 1,4 butane diol, and 1,6 hexane diol along with methacrylic acid towards the solventless green approach. The formations of the hydrogels were identified using FTIR spectroscopy. Thermal characterization (thermo gravimetric analysis, differential thermal analysis (DTA), and differential scanning calorimetry) and morphology of the synthesized hydrogels have been investigated. Swelling studies of hydrogels in various pH ranging from 4.0 to 10.0 have been investigated. The results of the swelling studies implied that percentage of swelling comparatively higher at neutral pH (7.4) than at acidic and alkaline pH. The inverse relationship was noticed, where ascending the diol units of hydrogel in swelling equilibrium. The hydrogels with the increasing chain length show a noticeable pH sensitivity and which could be considered as smart hydrogel. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41403.     

Polyaniline with high crystallinity degree: Synthesis,structure, and electrochemical properties

Polyaniline (PANI) with high crystallinity degree was facilely synthesized on the surface of stainless steel net by galvanostatic method. The effect of polymerization current density on the characteristics of morphology and structure had been investigated by field emission scanning electron microscopy (FE‐SEM), Fourier transforms infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), and X‐ray diffraction (XRD). FE‐SEM observations disclosed that PANI was deposited as nanofibers and their diameters decreased with the polymerization current density. FTIR studies revealed that degree of oxidation increased in order PANI‐2 < PANI‐6 < PANI‐10. XPS measurements displayed that PANI polymerized at 6 mA cm^?2 (PANI‐6) exhibited much higher doping level of 77.8%, which favored the conductivity. XRD analysis discovered that the obtained PANI showed high crystallinity degree in which PANI‐6 possessed highest crystallinity degree (X_cr) up to 67%. Electrochemical performances of PANI as electrode materials were studied via cyclic voltammetry. The results presented that PANI‐6 possessed greater discharge capacity and better reversibility. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40827.     

Synthesis of cationic hemicellulosic derivatives with a low degree of substitution in dimethyl sulfoxide media

A series of water‐soluble cationic 2‐hydroxylpropyltrimethylammonium hemicellulosic derivatives with low average degrees of substitution (DS's) were prepared by the incorporation of the cationic moiety 2,3‐epoxypropyltrimethylammonium chloride (ETA) onto the backbone of hemicelluloses in the presence of NaOH as a nucleophilic catalyst in homogeneous dimethyl sulfoxide (DMSO) media. The dependence of the homogeneous reaction on the different affecting factors was investigated. The average DS was calculated from the N/C ratio in the products and from the weight gain. The degree of substitution determined by the nitrogen content (DS_N) values up to 0.25 in a one‐step synthesis of the etherified hemicelluloses could be controlled by the adjustment of the amount of solvent used and the molar ratio of NaOH or ETA to the anhydromonomer units in the hemicelluloses. The structure of the cationic hemicellulosic derivatives formed was determined by Fourier transform infrared spectroscopy and further confirmed with solution‐state ¹³C‐NMR spectroscopy. In comparison, no significant degradation of the hemicellulosic derivatives occurred during the etherification of the polymers in the homogeneous DMSO system. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008