荞麦淀粉接枝型高吸水性树脂的性能分析

对荞麦淀粉接枝型高吸水性树脂的吸水倍率、吸水速率、重复吸水倍率、吸盐液倍率、自然条件下的失水率以及不同温度下的失水率等吸水和保水性能进行了分析.结果表明:荞麦淀粉-丙烯酸-丙烯酰胺三元接枝共聚物吸水快,且具有较高的吸水倍率,较好的保水性和耐盐性.     

响应面优化微波法制备芭蕉芋淀粉接枝丙烯酸高吸水性树脂工艺

研究响应曲面优化微波法制备芭蕉芋淀粉接枝丙烯酸高吸水性树脂的工艺。在单因素试验的基础上,采用响应曲面法研究单体用量、引发剂用量和单体中和度对树脂吸水倍率的影响,并对共聚物结构进行分析。结果表明,微波法制备芭蕉芋淀粉接枝丙烯酸高吸水性树脂的最佳工艺为单体丙烯酸与干淀粉比8.2:1(mL/g)、引发剂用量为干淀粉质量的2.8%、单体丙烯酸中和度80.1%时,此时树脂的吸水倍率为769g/g。红外扫描吸收谱表明,接枝共聚物中存在着羧基、酰胺基等特征性亲水性基团。     

高吸水吸湿纤维BELL OASIS

1　开发背景　　吸水树脂的开发 ,起始于 1 974年美国农业部把淀粉—丙烯腈的接枝共聚物进行水解而合成成功。以此技术为基础 ,目前以聚丙烯酸盐为主体 ,广泛地应用于纸尿布、卫生巾的工业生产。通常 ,吸水树脂是以粉末状、珠状的形态与浆粕合起来使用的。吸水树脂开发以来的二十几年中 ,其应用得到了惊人的发展。现在 ,世界年产量约为 90万 t。其中 ,90 %以上用于纸尿布 ,约 4%用于卫生巾 ,其余用于医疗材料和包装材料等其他用途。把吸水树脂做成更容易使用的形状 (例如纤维的形状 )的设想 ,通过最近的技术革新的新发展而得以实现 ,从而吸…     

高吸水性非织造布的研制

介绍了合成聚丙烯酸接枝淀粉浆液并使其在非织造布上形成吸水树脂 ,从而得到高吸水性非织造布的实验过程 ,对接枝单体的比例、交联条件、浸轧量及非织造布本身材质等因素对吸水非织造布吸水性能的影响进行了讨论。     

马铃薯淀粉复合吸水树脂合成工艺优化

选用马铃薯淀粉和高岭土、丙烯酸、丙烯酰胺为原料,以水溶液聚合法进行接枝共聚复合型吸水树脂合成的研究,并利用均匀设计法对合成工艺进行优化.优化后的合成条件是:当引发剂2 mL;交联荆1 mL;单体配比4:4(W:W);马铃薯淀粉2 g;反应温度65℃;反应时间2 h.制备的复合高吸水树脂吸蒸馏水可达960 g/g左右.     

原材料的选择和处理对合成淀粉接枝丙烯酸／丙烯酰胺高吸水树脂的影响

用水溶液法合成了淀粉接枝丙烯酸/丙烯酰胺高吸水树脂,主要讨论了淀粉类型、引发剂类型、交联剂类型、添加剂类型、淀粉预处理方式、引发剂比例、引发剂加入方式等对反应的接枝效率、合成树脂吸水/吸盐水性能的影响。     

原材料对合成高吸水树脂的影响

用水溶液法合成了淀粉接枝丙烯酸/丙烯酰胺高吸水树脂,主要讨论了淀粉类型、引发剂类型、交联剂类型、添加剂类型、淀粉预处理方式、引发剂比例、引发剂加入方式等对反应的接枝效率、合成树脂吸水/吸盐水性能的影响.     

原材料的选择和处理对合成淀粉接枝丙烯酸/丙烯酰胺高吸水树脂的影响

用水溶液法合成了淀粉接枝丙烯酸/丙烯酰胺高吸水树脂,主要讨论了淀粉类型、引发剂类型、交联剂类型、添加剂类型、淀粉预处理方式、引发剂比例、引发剂加入方式等对反应的接枝效率、合成树脂吸水/吸盐水性能的影响.     

改性淀粉超强吸水树脂反相乳液法合成与性能研究

以木薯淀粉为主要原料,高锰酸钾为引发剂,采用反相乳液聚合方法合成改性淀粉超强吸水树脂,考察反应过程中诸因素对吸水性能的影响。试验结果显示,采用反相乳液聚合方法能够得到具有高吸水率的改性淀粉接枝共聚产物;反应过程中乳液浓度、单体、交联剂、引发剂用量、反应温度、丙烯酸中和度等因素对改性淀粉吸水树脂吸水性能有显著的影响。     

引发剂对淀粉接枝聚丙烯酰胺影响的研究进展

淀粉-丙烯酰胺接枝共聚物具有价廉、无毒、易生物降解等优点,受到研究者的广泛重视.我国在淀粉接枝聚丙烯酰胺的研究方面比较深入,对引发剂影响如硝酸铈铵、过硫酸盐、锰盐、辐射法等进行对比研究,选用不同的接枝共聚工艺方式,优化反应工艺条件,制备了具有不同特性的淀粉接枝聚丙烯酰胺,并把接枝的淀粉应用在废水处理、造纸湿部、吸水剂等多方面.就我国目前几大类引发体系对淀粉接枝聚丙烯酰胺的制备与应用方面进行综述.     

脂质与淀粉相互作用及其对淀粉性质影响

淀粉是食品重要成分,在食品体系中起到提供热能与影响质构作用,在蒸煮、焙烤等加热过程中,淀粉粒开始吸水膨胀,淀粉性质发生变化。淀粉中脂质或外加入脂质在淀粉加热过程中,影响淀粉特性变化;脂质存在会使淀粉溶胀性和溶解性降低,改变糊化温度和热焓,对淀粉流变性质也会产生影响。     

Cereal starch nanoparticles—A prospective food additive: A review

Starch is one of the most abundant biopolymers in nature and is typically isolated from plants in the form of micro-scale granules. Raw starch has limited applications due to its innate disadvantages such as poor solubility in cold water, tendency to retrograde and high viscosity once it is gelatinized. Therefore, some degree of modification is required to enhance its functionality. Starch nanoparticle is one of the products of such modification. Chemical, enzymatic, and physical treatments are used for the preparation of starch nanoparticles and to study their granular and molecular structures. Characterization of starch nanoparticles on the size distribution, crystalline structure, and physical properties in relation to the starch sources and preparation methods can be done using various characterization tools e.g. Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Florescence Microscopy, etc. Starch nanoparticles can be used as a food additive as it has adverse range of uses in food such as emulsion stabilizer, fat replacer, Thickener, or rheology modifier etc.     

Form and functionality of starch

Starch is a macro-constituent of many foods and its properties and interactions with other constituents, particularly water and lipids, are of interest to the food industry and for human nutrition. Starch varies greatly in form and functionality between and within botanical species, which provides starches of diverse properties but can also cause problems in processing due to inconsistency of raw materials. Being able to predict functionality from knowledge of the structure, and explain how starch interacts with other major food constituents remain significant challenges in food science, nutrition, and for the starch industry generally. This paper describes our current understanding of starch structure that is relevant to its functionality in foods and nutrition. Amylose influences the packing of amylopectin into crystallites and the organization of the crystalline lamellae within granules, which is important for properties related to water uptake. Thermal properties and gel formation appear to be influenced by both amylose content and amylopectin architecture. While amylose content is likely to have an important bearing on the functional properties of starch, subtle structural variations in the molecular architecture of amylopectin introduces uncertainty into the prediction of functional properties from amylose content alone. Our ability to relate starch granule structure to suitability for a particular food manufacturing process or its nutritional qualities depends not only on knowledge of the genetic and environmental factors that control starch biosynthesis, and in turn granule morphology, but also on how the material is processed.     

Vergleichende Kernresonanzuntersuchungen der Wasserbindungsverhältnisse von Stärke und rohen Kartoffelstücken während der Trocknung

Comparative NMR-Investigations of the Binding of Water in Starch and Raw Potatoes During the Drying Process. A reversible swelling which is caused partly by reorientational motion of water is observed by heat-moisture-treatment of native starch at 60°C. This means that water can either only loosen the outer amylopectine layer or that it gets through to the inner part of a starchgranule to become less loosely associated with amylose. Obviously this behaviour is important during hot-air-drying of potatoes. The drying-up of the outer layers of the material to be dried means a reduction of the self-diffusion-coefficient and a hindrance to the discharge of water. But apart from this another influence upon the drying-speed is observed which is in direct connection with the behaviour of starch already mentioned above. Soon at the beginning it is to be noticed that the mobility of the water within the cell increases and that it gets transported into the middle of the potato. At a temperature of 50°C to 60°C the swelling of starch starts and water therefore becomes immobilized. To some extend some water becomes enclosed in existing structures where it remains relatively flexible. These processes can be followed by nuclear-magnetic-resonance (NMR-Spectroscopy). On this basis statements about different water-molecules and their particular quantities can be made. The immobilisation of the water can be shown by the smaller water activity of the starch samples after the heat-moisture-treatment. Also it can be seen in the lowering of the drying speed.     

Kernresonanzuntersuchungen zum Einfluß der technischen Aufarbeitung auf die Wasserbindungsfähigkeit von Kartoffelstärke

Nuclear Resonance Investigations Regarding the Influence of the Preparation on the Water Binding Capacity of Potato Starch . In a preceding paper we stated that an increased content of more tightly bound water has been observed in a sample of industrial potato starch in comparison with a sample of starch which has been isolated under carefully controlled conditions. Now it can be shown that the conditions of drying and also the size of the starch granules have no influence on the above mentioned difference, in spite of the fact that the portion of more tightly bound water distinctly depends on the granule size. The differences in the behaviour of the bound water can be explained by the ion content of the water used during the isolation of the starch. The mechanism of this effect, however, is not yet clear.     

Röntgenographische und Kernresonanz-Untersuchungen einiger Strukturfragen an Stärke

X-Ray and Nuclear Magnetic Resonance Investigations on Some Structure Problems of Starch. For NMR-spectroscopical investigations on the structure of starch it is important to know the exact location of the water molecules in the granule. By means of D-resonance it could be observed that blocking of the helices of potato starch by iodine had no influence on the structure of the water. By defined methods of degradation of potato starch it could furthermore be observed that the chain length of the amylose molecules does not influence the structure of the water from which we concluded that the water in starch is adsorbed interhelical and not intrahelical. This result is in good agreement with the actual state of knowledge of the structure of the helix of which the inner surface is regarded as hydrophobic and the outer surface as hydrophilic.     

辛烯基琥珀酸淀粉酯的研究现状

辛烯基琥珀酸淀粉酯(OSA-starch)是一种新兴的改性淀粉,是以辛烯基琥珀酸酐和淀粉经酯化反应制得,通常以淀粉酯(OSA-starch)或淀粉钠的形式出现,其具有同型产品不可比拟的优良性质,目前其种类达到60种之多,市场前景广阔,近年来吸引了国内外学者的广泛关注。本文就辛烯基琥珀酸淀粉酯的结构、性质、反应原理、制备工艺、国内外研究现状以及在工业中的应用做一简单介绍,旨在为开发新种类的辛烯基琥珀酸淀粉酯提供参考。     

Low‐ and High‐temperature Processes and Mechanisms in the Preparation of Porous Ceramics via Starch Consolidation Casting

Starch consolidation casting (SCC) is a versatile and well established process for shaping ceramic green bodies by casting starch‐containing suspensions into impermeable molds. The process is based on the ability of starch to swell and absorb water from aqueous ceramic suspensions after heating to approx. 80°C. The swelling factor is highest for potato starch (3.7) and significantly lower for the other starch types (down to approx. 2). A simple mathematical model is presented that allows the minimum consolidation time to be estimated on the basis of the swelling kinetics of starch granules as measured via laser diffraction. The critical temperature range for starch burnout before sintering the ceramic is 300–500°C, as determined by thermal analysis (thermogravimetry and differential thermal analysis). In this temperature range gaseous products may ignite, leading to strongly exothermic thermal effects. If the bodies are large and the starch content high this may lead to defects in the (still unsintered) ceramic green bodies. Therefore this temperature range has to be carefully controlled in the production of ceramics prepared by SCC. The residual pores (remaining after starch burnout) are too large to be closed during the firing step (insufficient driving force for sintering due to too low surface curvature). Therefore they do not contribute to shrinkage, and shrinkage is determined by the ceramic matrix alone. Porosities higher than 50% (corresponding to the maximum nominal starch content) may be obtained by combining SCC with partial sintering (resulting in porosities up to 70%).     

Starch Retrogradation: A Comprehensive Review

Starch retrogradation is a process in which disaggregated amylose and amylopectin chains in a gelatinized starch paste reassociate to form more ordered structures. Starch retrogradation has been the subject of intensive research over the last 50 years, mainly due to its detrimental effect on the sensory and storage qualities of many starchy foods. However, starch retrogadation is desirable for some starchy food products in terms of textural and nutritional properties. To better understand the effect of starch retrogradation on the quality of starchy foods, measurement methods of starch retrogradation and factors that influence starch retrogradation have been studied extensively. This article provides a comprehensive review of starch retrogradation including the definition of the process, molecular mechanisms of how it occurs, and measurement methods and factors that influence starch retrogradation. The review also discusses the effect of retrogradation on the in vitro enzyme digestibility of starch. Spectroscopic methods such as FTIR and Raman are considered to be very promising in characterizing starch retrogradation at a molecular level, although more studies are needed in the future.     

Gelatinierungsverhalten von Weizenstärke in einem zweiwelligen Knetgerät

Gelatinization Behaviour of Wheat Starch in a Twin Screw Mixer. Native starch with something additives such as distilled water and glycerin can be gelatinized in a twin screw mixer. The degree of starch gelatinization depends on residence time, temperature, pressure, speed of rotation and concentration of additives. This paper shows that the samples of starch were prepared at concentrations of 20, 30 and 40% of destilled water in a plastograph. Then the degree of starch gelatinization was determined by means of Differential Scanning Calorimetry (DSC). The results show that the degree of starch gelatinization increases greatly with the increase of residence time and specific mechanical energy at the beginning of the experiment. And then it increases slowly until reaching 100%. On the other hand the increase of destilled water slows down the gelatinization. In order to describe the gelatinization process a mathematical model is found. The calculated degree of gelatinization agrees with the experimental results.