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Incorporation in pasta of either of two soluble fibres, carboxymethylcellulose sodium salt (CMC) and guar gum (GG), was found to significantly reduce the rate of invitro starch digestion. The amount of reducing sugars produced over 300 min was reduced by 18% at 1.5% CMC incorporation and 24% at 20% GG incorporation. Negative effects on sensory and technological properties were seen at the high levels of GG needed to reduce the rate of in vitro digestion, and a ‘matty’ layer covering the surfaces of starch granules was observed by scanning electron microscopy and confocal scanning laser microscopy. By contrast, levels of CMC incorporation giving large reductions in in vitro digestion had no negative effects on pasta properties. No significant alteration in pasta structure on CMC incorporation was observed by microscopy. The large difference in the amounts of soluble fibre required to bring about equivalent reductions in digestion rate suggests that different mechanisms may be involved in the two cases. 相似文献
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H.N.M.Ekramul Mahmud Anuar Kassim Zulkarnain Zainal Wan Mahmood Mat Yunus 《材料科学技术学报》2005,21(5):661-665
1.IntroductionConjugated polymers such as polypyrrole(PPY),polyaniline,polythiophene and polyphenylene etc.whichexhibit significant level of electrical conductivity andhence are termed as conducting polymers,have gotversatile promising applications in the field of energystorage[1],sensors[2],electronic and optical devices[3]andso on.Many researches have been conducted to pro-duce composites or blends of conducting polymer filmswith some insulating polymers in order to overcome thedrawbacks su… 相似文献
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CMC和AA/AM三元共聚高吸水树脂的研究 总被引:2,自引:0,他引:2
以N, N-亚甲基双丙烯酰胺为交联剂,过硫酸铵和亚硫酸氢钠为引发剂,羧甲基纤维素(CMC)-丙烯酰胺(AM)-丙烯酸(AA)为原料进行共聚合成了高吸水树脂,研究了单体、中和度、交联剂等因素对产品吸水性能的影响. 相似文献
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The objective of this study was to investigate the effect of the addition of methylcellulose and carboxymethylcellulose on the thermal, mechanical and water adsorption properties of starch-based films plasticized with glycerol or polyethylene glycol (PEG). Mechanical tests showed that as the methylcellulose and carboxymethylcellulose proportion increased, starch films became more resistant to break, resulting in higher TS values. Besides there has been a positive effect on the elasticity of starch films realized by a considerable increase in E% values. Depending on the plasticizer type, either single or dual glass transitions were seen in DSC thermograms. One glass transition temperature was observed for films plasticized with glycerol, on the contrary, dual glass transitions were detected for PEG plasticized films. This behavior was attributed to the phase separation of the PEG. In addition, the presence of an endothermic peak in the thermograms of PEG plasticized films was taken as another indicator of the phase separation. As a result, it was suggested that PEG was not as compatible as glycerol with the composite polysaccharide matrix and plasticizer type was the main factor that shaped the thermal profiles of the film samples. Water adsorption isotherm data showed that samples displayed nonlinear sorption profile which is typical for hydrophilic films. In all films tested, equilibrium moisture contents, increased almost linearly up to a aw of 0.65–0.85, beyond where a sharp increase was noted. Adsorption data was adequately fitted by BET and GAB models. Eventually, it can be concluded that film forming properties of starch can be improved by incorporation of methylcellulose and carboxymethylcellulose to the polymer matrix. 相似文献
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Marcel Popa Nicu Bajan Marcel Ionel Popa Aura Angelica Popa 《Polymer-Plastics Technology and Engineering》2013,52(1):23-28
This paper presents a diffusional system consisting of tolazoline hydrochloride included into a carboxymethylcellulose based hydrogel, showing a high swelling capacity in water. The process kinetics of the drug inclusion into hydrogel as well as of the drug releasing have been studied. The tolazoline hydrochloride release was performed by elution with a simulated biological fluid within the digestive tract, at the small intestine level (pH = 8.2) where the drug is mostly absorbed. The results make evident a zero-order kinetics over the 30–400 min range, which would place the system among those with ‘sustained’ release, with obvious advantages compared with the classical drug administration. 相似文献
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Porous oil absorbents have been extensively studied in recent years. Boron nitride (BN) is an ideal inorganic material to withstand severe absorption conditions due to its excellent inertness and high-temperature resistance. A large challenge of BN aerogels is their high preparation costs due to requiring high temperatures and dangerous atmospheres. A facial synthesis of h-BN-based aerogels by the cast-freezing method is reported here, which has the advantages of producing a light and recyclable material (~0.035 g/ml) at a low cost and with low energy consumption. In this work, carboxymethylcellulose (CMC) is used as the compounder to interact with BN and form an aerogel that has controllable porosity (38–86 μm) and hydrophobicity (~140°). The porous structure, components, and reaction mechanisms are analyzed by SEM, XRD, mercury porosimetry, etc.. The pore distributions can be controlled by the concentrations of CMC and crosslinking agents. The intercalation effect on BN is carried out by CMC, which increases the specific surface area. Finally, the oil absorption performances are measured. The oil absorption capacity is up to 31.55 g/g (~97% ml/ml) because of the high specific surface area of the prepared material; additionally, the capacity of this material shows no obvious decrease after 6 cycles. Therefore, h-BN-based aerogels are expected to be applied in the oil absorption field and have the potential to be applied in the biochemical and nuclear fields. 相似文献
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纤维素醚经N-羟甲基丙烯酰胺交联制备高吸水材料的研究 总被引:2,自引:0,他引:2
研究了羧甲基纤维素经 N-羟甲基丙烯酰胺交联制取高吸水材料的工艺方法和产品性能,讨论了结构、交联度、溶剂用量对产品吸附性能的影响,解释了该吸水材料对水和生理盐水的吸附机理。研究表明,本工艺方法可制取水吸附保持值200~260ml/g、生理盐水吸附保持值为60~67ml/g 的产品。 相似文献
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