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ABSTRACT: Carboxymethyl potato starch (CMPS) was synthesized with a simple dry and multi-step method as a product of the reaction of native potato starch and monochloroacetic acid in the presence of sodium hydroxide. The influence of the molar ratio of sodium hydroxide to anhydroglucose unit, the volume of 95% (v/v) ethanol, the rotation rate of motor driven stirrer and the reaction time for degree of substitution (DS) were evaluated. The product was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffractometry (XRD). FTIR spectrometry showed new bonds at 1618 and 1424 cm⁻¹ when native starch underwent carboxymethylation. SEM pictures showed that the smooth surface of native starch particles was mostly ruptured. XRD revealed that starch crystallinity was reduced after carboxymethylation. The viscosity of the mixture paste of carboxymethyl starch and sodium alginate (SA) was measured using a rotational viscometer. In addition, the applied effect of mixed paste in reactive dye printing was examined by assessing the fabric stiffness, color yield and sharp edge to the printed image in comparison with SA. And the results indicated that the mixed paste could partially replace SA as thickener in reactive dye printing. The study also showed that the method was low cost and eco-friendly and the product would have an extensive application in reactive dye printing.
International journal of biological macromolecules 07/2012; 51(4):668-74. · 2.37 Impact Factor
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ABSTRACT: With the aim of improving fertilizer use efficiency and minimizing the negative impact on the environment, a new coated controlled-release fertilizer with the function of water retention was prepared. A novel low water solubility macromolecular fertilizer, poly(dimethylourea phosphate) (PDUP), was "designed" and formulated from N,N'-dimethylolurea (DMU) and potassium dihydrogen phosphate. Simultaneously, an eco-friendly superabsorbent composite based on wheat straw (WS), acrylic acid (AA), 2-acryloylamino-2-methyl-1-propanesulfonic acid (AMPS), and N-hydroxymethyl acrylamide (NHMAAm) was synthesized and used as the coating to control the release of nutrient. The nitrogen release profile and water retention capacity of the product were also investigated. The degradation of the coating material in soil solution was studied. Meanwhile, the impact of the content of N-hydroxymethyl acrylamide on the degradation extent was examined. The experimental data showed that the product with good water retention and controlled-release capacities, being economical and eco-friendly, could be promising for applications in agriculture and horticulture.
Journal of Agricultural and Food Chemistry 06/2012; 60(28):6921-8. · 2.82 Impact Factor
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ABSTRACT: A novel substance, cationic acetylcholine potato starch (CAPS), was developed for the first time. The synthesis process had three steps: first, carboxymethyl potato starch (CMPS) was synthesized under sodium hydroxide alkaline condition and in isopropyl alcohol organic media; second, bromocholine chloride (BCC) was synthesized with sulphuric acid as a catalytic agent; finally, CAPS was synthesized by the reaction of CMPS with BCC in N,N'-dimethylformamide (DMF). The degree of substitution (DS) of CAPS was determined by ammonia gas-sensing electrode and elemental analysis. CAPS was characterized by Fourier transformed infrared (FTIR) and near infrared (FTNIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC).
International journal of biological macromolecules 04/2012; 50(3):701-6. · 2.37 Impact Factor
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ABSTRACT: Acetylated corn starch (ACS) was synthesized by the reaction of native corn starch (NCS) with acetic anhydride (AA) in an aqueous medium in the presence of sodium hydroxide as a catalyst. The factors that could affect the degree of substitution (DS) and reaction efficiency (RE) of corn starch were investigated which included the reaction temperature and time, the mass ratio of AA to starch, the ratio of the water volume to starch mass and pH. The optimal DS of 0.071 and RE of 67.05% was obtained. FTIR spectrometry showed new bands at 1733, 1375 and 1252 cm(-1). The SEM of the ACS indicated some cavities on the granules which fused together, compared with NCS. Wide angle X-ray diffraction revealed that ACS had a similar profile as NCS (A type). However, the intensity of peaks were diminished. DSC thermograms exhibited that ACS had some lower gelatinization temperatures and enthalpies than NCS. The functional properties of ACS such as the swelling power, solubility, water absorption, clarity, freeze-thaw stability, retrogradation and viscosity were also studied. The results suggest that the ACS has much better functional properties than the NCS, and could be expected to have wide applications especially in food industry.
International journal of biological macromolecules 03/2012; 50(4):1026-34. · 2.37 Impact Factor
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ABSTRACT: To improve the utilization of fertilizer and water resources at the same time, a new slow-release PK compound fertilizer (SRCF) with the function of water retention was prepared. Element analysis results showed that the product contained 20.46% potassium (shown by K2O) and 15.45% phosphorus (shown by P2O5), which were trapped in the matrix of carboxymethylcellulose-graft-poly(acrylic acid-co-itaconic acid) superabsorbent polymer. Major factors affecting the water absorbency of SRCF such as weight ratio of itaconic acid (IA) to acrylic acid (AA), contents of crosslinker, K2HPO4, and carboxymethylcellulose (CMC) were investigated and optimized. The water absorbency of the product was 130 times its own weight if it was allowed to swell in tap water at room temperature for 1 h. Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric/Differential thermal analysis (TG/DTA) confirmed that AA and IA monomers were graft-copolymerized onto CMC backbone and presented the improved thermal stability. The water evaporation of the fertilizer-containing superabsorbents, as well as their nutrients release in sandy soil was carried out, and a possible slow-release mechanism was proposed. Additionally, compressive modulus measurements revealed that the introduction of CMC could improve the mechanical properties of the superabsorbents. These studies showed that the product with good slow-release and water retention properties, being economical and environment-friendly, could be expected to have wide potential applications in modern agriculture and horticulture.
Journal of Macromolecular Science. 10/2011; Part A(Vol. 48):806-815.
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ABSTRACT: The aim of this study was to prepare oxidized guar gum with a simple dry method, basing on guar gum, hydrogen peroxide and a small amount of solvent. To obtain a product with suitable viscosity for reactive dye printing, the effects of various factors such as the amount of oxidant and solvent, reaction temperature and time were studied with respect to the viscosity of reaction products. The product was characterized by Fourier transform infrared spectroscopy, size exclusion chromatography, scanning electron microscopy and differential scanning calorimetry. The hydrated rate of guar gum and oxidized guar gum was estimated through measuring the required time when their solutions (1%, w/v) reached the maximum viscosity. The effects of the salt concentration and pH on viscosity of the resultant product were studied. The mixed paste containing oxidized guar gum and carboxymethyl starch was prepared and its viscosity was determined by the viscometer. The rheological property of the mixed paste was appraised by the printing viscosity index. In addition, the applied effect of mixed paste in reactive dye printing was examined by assessing the fabric stiffness, color yield and sharp edge to the printed image in comparison with sodium alginate. And the results indicated that the mixed paste could partially replace sodium alginate as thickener in reactive dye printing. The study also showed that the method was low cost and eco-friendly and the product would have an extensive application in reactive dye printing.
International journal of biological macromolecules 09/2011; 49(5):1083-91. · 2.37 Impact Factor
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ABSTRACT: To sustain the further world population, more fertilizers are required, which may become an environmental hazard, unless adequate technical and socioeconomic impacts are addressed. In the current study, slow-release formulations of nitrogen fertilizer were developed on the basis of natural attapulgite (APT) clay, ethylcellulose (EC) film, and sodium carboxymethylcellulose/hydroxyethylcellulose (CMC/HEC) hydrogel. The structural and chemical characteristics of the product were examined. The release profiles of urea, ammonium sulfate, and ammonium chloride as nitrogen fertilizer substrates were determined in soil. To further compare the release profiles of nitrogen from different fertilizer substrates, a mathematical model for nutrient release from the coated fertilizer was applied to calculate the diffusion coefficient D. The influence of the product on water-holding and water-retention capacities of soil was determined. The experimental data indicated that the product can effectively reduce nutrient loss, improve use efficiency of water, and prolong irrigation cycles in drought-prone environments.
Journal of Agricultural and Food Chemistry 08/2011; 59(18):10169-75. · 2.82 Impact Factor
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ABSTRACT: Multifunctional slow-release organic-inorganic compound fertilizer (MSOF) has been investigated to improve fertilizer use efficiency and reduce environmental pollution derived from fertilizer overdosage. The special fertilizer is based on natural attapulgite (APT) clay used as a matrix, sodium alginate used as an inner coating and sodium alginate-g-poly(acrylic acid-co-acrylamide)/humic acid (SA-g-P(AA-co-AM)/HA) superabsorbent polymer used as an outer coating. The coated multielement compound fertilizer granules were produced in a pan granulator, and the diameter of the prills was in the range of 2.5-3.5 mm. The structural and chemical characteristics of the product, as well as its efficiency in slowing the nutrients release, were examined. In addition, a mathematical model for nutrient release from the fertilizer was applied to calculate the diffusion coefficient D of nutrients in MSOF. The degradation of the SA-g-P(AA-co-AM)/HA coating was assessed by examining the weight loss with incubation time in soil. It is demonstrated that the product prepared by a simple route with good slow-release property may be expected to have wide potential applications in modern agriculture and horticulture.
Journal of Agricultural and Food Chemistry 11/2010; · 2.82 Impact Factor
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ABSTRACT: Poly(N-vinyl-pyrrolidone) (PVP) hydrogel has been considered as a very interesting and promising thermosensitive material. The most vital shortcoming of PVP hydrogel as thermosensitive material is that it does not exhibit thermosensitivity under usual conditions. In this work, semi-interpenetrating polymer network (semi-IPN) hydrogels based on PVP and carboxymethylcellulose (CMC) were prepared. The volume phase transition temperature (VPTT) of the hydrogels was determined by swelling behavior and differential scanning calorimetry (DSC). The results showed that the VPTT was significantly dependent on CMC content and the pH of the swelling medium. The amount of CMC in the semi-IPN hydrogels was 0.050, 0.075, and 0.100 g, the VPTT in buffer solution of pH 1.2 was 29.9 °C, 27.5 °C and 24.5 °C, respectively. In addition, the VPTT occurred in buffer solution of pH 1.2, but did not appear in alkaline medium. Bovine serum albumin (BSA) as a model drug was loaded and the in vitro release studies were carried out in different buffer solutions and at different temperatures. The results of this study suggest that PVP/CMC semi-IPN hydrogels could serve as potential candidates for protein drug delivery in the intestine. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1749–1756, 2010
Journal of Polymer Science Part B Polymer Physics 06/2010; 48(15):1749 - 1756. · 1.53 Impact Factor
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ABSTRACT: To improve the utilization of fertilizer and water resources at the same time, a novel slow-release multielement compound fertilizer (SMF) with the function of water retention was prepared. The fertilizer nutrients (11.3% N, 9.6% P2O5, 6.1% K2O, and 0.76% Cu) were entrapped in the alginate matrix granules, and the sodium alginate-g-ploy(acrylic acid) (SA-g-PAA) superabsorbent polymer was used as a coating material. The structural and chemical characteristics of the product as well as its efficiency in slowing nutrient release and water evaporation in soil were examined. The degradation of the SA-g-PAA coating was assessed by examining the weight loss with incubation time in soil. Additionally, the nutrient release mechanism was proposed and the diffusional exponent n was calculated. These studies showed that the product with good slow-release and water-retention properties, being partially degradable in nature, could be expected to have wide potential applications in modern agriculture and horticulture.
04/2010;
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ABSTRACT: The aim of this study was to prepare a double-coated, slow-release, and water-retention urea fertilizer (DSWU) to reduce environment pollution derived from excessive nitrogen fertilizer use. Ethylcellulose (EC) and crosslinked poly(acrylic acid-co-acrylamide) (P(AA-co-AM)) were used as inner and outer coating materials, respectively. The structural and chemical characteristics of the product, as well as its efficiency in slowing the nitrogen release and water evaporation in soil were examined. The nitrogen content of the product was 21.1% and its water absorbency was 70 times its own weight in tap water. Additionally, the biodegradation of EC coating in soil was assessed by differential scanning calorimetry (DSC) measurements. The results showed that the glass transition temperature (Tg) of EC coating decreased with the time prolonged, which indicated the biodegradability of EC coating in soil. These studies showed that the product with good slow-release and water-retention properties, being environmentally friendly, would find good application in agriculture and horticulture.
Chemical Engineering Journal.
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ABSTRACT: CMC-g-PNIPAAm copolymers were developed by decorating the backbone of carboxymethylcellulose (CMC) with linear chains of poly(N-isopropylacrylamide) (PNIPAAm), with the ultimate aim of synthesizing a biodegradable and injectable hydrogel that also possesses a low gelation concentration. Their aqueous solutions were found to undergo a reversible subphysiological phase transition at the concentration of 2 wt%. The value is much lower than that reported for many PNIPAAm-based copolymers. The phase transition behavior, gelation time, injectability, viscosity, swelling, degradation and cytocompatibility were explored. The model drug lysozyme was easily incorporated into the hydrogel by mixing with the gel precursors prior to heating. In vitro release of lysozyme from the in situ forming hydrogel was studied. Secondary and tertiary structure analysis and biological assays of the released protein showed that encapsulation and release did not affect the protein conformation and functionality. These results indicate that this biocompatible and injectable hydrogel system may be useful as a potential vehicle for therapeutic proteins for sustained release applications.Graphical abstractHighlights► A biodegradable and injectable hydrogel was synthesized. ► The gelation characteristics relevant to physiological applications were studied. ► The hydrogel had a comparatively lower polymer concentration. ► The activity of the proteins was maintained after release.
Chemical Engineering Journal. 173(1):241-250.
