Papers by Keyword: Starch

Abstract: The hydrophobicity of starch/PVA blend was improved by crosslinking with boric acid. It was found that the swelling ratio of the boric acid modified starch/PVA matrix decreased as function of boric acid concentration. FTIR spectra and SEM images demonstrated that the urea had been encapsulated in polymer matrix successfully. The urea release characteristic was explained with respect to the swelling ratio and crosslinking density of polymer matrix. In addition, the matrix displayed a good barrier for controlling the release rate of urea from pellet.

Abstract: A novel starch-g-poly (acrylic acid) hydrogel was prepared by graft-copolymerization among starch, acrylic acid in aqueous solution with potassium persulfate as an initiator, N, N-methylenebisacrylamide as a crosslinking agent. Characterization of the graft copolymer was carried out by X-ray diffraction, FTIR and SEM analytical methods. Swelling kinetic analysis in distilled water was done to study the swelling behavior of the product. The results show that the product exhibits water absorption of 786g/g in distilled water at ambient temperature. It has been proved that the grafting of acrylic acid onto starch was successful and the aggregation of phase of native starch was changed from semi-crystalline state to amorphous aggregation state due to copolymerization.

Abstract: Nano-sized starch particles were prepared from potato starch via high-energy ball milling, which is a purely physical method. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and viscometer were used to analyze the morphology and characteristics of the as-prepared nanoparticles. Spherical particles with an average size of approximately 120 nm were obtained after grinding the samples for 90 min, and the particles were free from any contamination. The particle surface was rough with a plush-like feature, and the adsorption ability was six times higher than that of native starch. Thus, the nano-sized starch particles can be used as a good embedding medium in biomedical and chemical materials.

Abstract: Solid polymer electrolyte (SPE) can be viewed as an alternative of conventional liquid electrolyte since it is easier to handle. Previous Solid polymer electrolyte (SPE) can be viewed as an alternative of conventional liquid electrolyte since it is easier to handle. In the present work, starch/chitosan-ammonium nitrate (NH₄NO3) SPE has been prepared by solution casting technique. Different amount of 1-ethyl-3-methylimidazolium nitrate ([EMIM][NO₃]) was added to the sample. Ionic conductivity analysis was conducted over a wide range of frequency between 50 Hz-1 MHz using impedance spectroscopy to evaluate the dielectric properties and conductivity of the sample. Sample with 15 wt% of [EMIM][NO₃] has shown the highest conductivity of 7.36 x 10^-5 S cm^-1 at room temperature. Complex permittivity for real (ε_r), imaginary (ε_i) and electrical modulus for real (M_r) and imaginary (M_i) part was determined and plotted.

Abstract: The objective of the study was to evaluate the dimensional stability of experimental particle board panels made from rubberwood (Hevea brasiliensis) using modified starch as binder. Panels were manufactured using 15% corn starch modified with glutardialdehyde and 13% modified starch with 2% Urea Formaldehyde resin as improvement. The particle boards were tested for their dimensional stability towards moisture. Results found that the 2% replacement of modified starch with urea formaldehyde resin showed increment in dimensional stability compared to using glutardialdehyde modified corn starch only as the binder, recorded at 39.38 % and 23.47 % for particleboard with 0.80 g/cm³ density after exposed to 75% and 95 % relative humidity. Therefore, this study indicated that combination of modified corn starch and urea formaldehyde resin can have a potential to be used as an improved binder to produce particle board panels with accepted properties.The objective of the study was to evaluate the dimensional stability of experimental particle board panels made from rubberwood (Hevea brasiliensis) using modified starch as binder. Panels were manufactured using 15% corn starch modified with glutardialdehyde and 13% modified starch with 2% Urea Formaldehyde resin as improvement. The particle boards were tested for their dimensional stability towards moisture. Results found that the 2% replacement of modified starch with urea formaldehyde resin showed increment in dimensional stability compared to using glutardialdehyde modified corn starch only as the binder, recorded at 39.38 % and 23.47 % for particleboard with 0.80 g/cm³ density after exposed to 75% and 95 % relative humidity. Therefore, this study indicated that combination of modified corn starch and urea formaldehyde resin can have a potential to be used as an improved binder to produce particle board panels with accepted properties.

Abstract: Effects of filler loading on the mechanical properties of Epoxidised natural rubber (ENR) filled with bio-fillers were studied. The compounds with different filler loadings (0, 30, 50, 70 phr) were prepared in a Haake internal mixer. Result showed that the viscosity of the compounds increased with filler loading and exhibited longer cure time with higher loading of the bio-filler. The mechanical properties of starch-filled vulcanisates present better tensile strength at 50 phr when compared to micro-crystalline cellulose (MCC) filled vulcanisates at similar filler loadings. The scanning electron microscopy (SEM) of tensile fracture surface of 50 phr starch-filled vulcanisates illustrated a homogenous distribution in comparison with MCC-filled compounds.

Abstract: This paper presents the development of silver nanoparticles entrapped starch-polyacrylic acid hydrogel by a one step facile strategy. Formation of silver nanoparticles was confirmed by TEM and SPRE. Hydrogen bond interaction present in the hydrogel network was manifested from the FTIR spectroscopy. Silver nanoparticles in the face centred cubic lattice were confirmed by XRD. Visco-elastic properties studied by rheological analysis showed storage modulus of ~1500 Pa and exhibited a high storage modulus than loss modulus revealing the formation of strong gels. Phase transition temperature was confirmed by DSC. Antimicrobial screening studies of these hybrid gel exhibited antimicrobial activity to E.coli and S.aureus suggesting its applications for gram + ve and gram - ve bacteria.

Abstract: A flexible, controllable and facile synthesis route was presented in the synthesis of spherical particles of mesoporous SBA-15 with diameter up to 28 nm, and particle diameter of 3-5 µm. The structures and morphology of these materials were characterized by powder X-ray diffraction (XRD), nitrogen adsorption analysis and scanning electron micrographs (SEM). The relationship between the porous property of silica and the weight ratio of starch to TMB were discussed. It indicates that the weight ratio of starch to TMB have a significant effect on the pore size, the surface area and also contribute to a narrow pore size distribution.

Abstract: By means of solution polymerization, a series of cross-linked starch-g-polyacrylamide/ montmorillonite (St-g-PAM/MMT) nanocomposites were prepared and used to adsorb methylene blue (MB). The effects of different preparation conditions on the adsorption capacity of the nanocomposites were investigated. The experimental results demonstrated that the prepared St-g-PAM/MMT nanocomposites were effective adsorbents for removal of MB from aqueous solution. Furthermore, adsorption capacity increased with the MMT contents up to 14% and decreased as the MMT contents further increased. Adsorption capacity increased with the increasing of the ratio of starch to acrylamide, whereas adsorption capacity decreased with the increasing of crosslinking agent contents.

Abstract: The traditional architectural ceramic body is mainly molded by compression forming process with dry power. The study introduced the starch into the body formula and the feasibility and correlate technological means of the situ solidification forming of fly ash architectural ceramics body with full barren materials were discussed. The body with full barren materials has a low green strength which is less than 1MPa by the traditional compression forming with dry power. But it could be improved greatly by optimizing the kind and amount of starch and the heat holding technologies in the forming process. The research showed that the body’s green strength is higher by introducing modified potato starch. The sintered body’s porosity and water absorption will be increased and lower flexural strength will be obtained by more starch. The body’s properties show the best when the amount of the starch reached 4wt% and the holding time for demoulding is 70min under the holding temperature what is 80°C. Under that molding condition, the green strength reached 3.61MPa, the flexural strength and water absorption of the sintered body reached 49.01MPa and 0.17% separately.