加快淀粉粘合剂干燥速度的方法及其干燥剂

本文阐述了淀粉粘合剂干燥过程的本质，介绍了几种较为实用的干燥剂的催干原理，采用将部分溶剂（水）转化为胶膜成分的方法，提高干燥速度。     

包醛酶淀粉吸附性能的研究

本文介绍了肠溶制剂包醛酶淀粉在尿素溶液中的吸附性能，以及溶液的浓度，ｐＨ值，吸附剂用量对吸附性能的影响。结果表明，包醛酶淀粉的吸附速度大于包醛氧淀粉，吸附容量大约是包醛氧淀粉的４倍，当溶液ｐＨ〈４时，随着ｐＨ值减小，对溶液中尿素的吸附力迅速降低。     

淀粉基吸附剂处理电镀废水的研究现状

淀粉基吸附剂是一类可再生易降解,具有良好吸附性能的绿色环保型吸附剂,其在环境废水治理中的研究开发应用,受到人们的广泛关注。综述了淀粉基吸附剂处理电镀废水在我国的研究应用情况,并展望了淀粉基吸附剂在处理电镀废水中的应用前景。     

淀粉基化学品用作吸附剂的应用研究进展

近年来随着石油资源的枯竭,人们对于可再生资源越来越关注,对淀粉基吸附剂的研究逐渐增加。综述了以淀粉为基材制备吸附剂及其吸附重金属离子、染料及其他物质的研究现状,并介绍了纳米淀粉改性用作吸附剂的应用情况,最后对淀粉基化学品用作吸附剂的发展趋势进行了展望。     

淀粉和纤维素基高吸水性树脂的制备与性能

对以淀粉或羧甲基纤维素为原料,用丙烯酸进行接枝共聚得到高吸水性树脂作了介绍。将丙烯酸用氢 氧化钠部分中和,然后与淀粉或羧甲基纤维素共混,用水溶性的过硫酸铵做引发剂,Ｎ,Ｎ－亚甲基双丙烯酰胺做交联 剂,在一定的反应温度下得到了不同吸水能力的高吸水性树脂;找到了吸水能力与天然高分子加入量之间的关系。 以淀粉和羧甲基纤维素为原料的产物的最高吸水能力分别为 １０８ｇ·ｇ－１及 １５２ｇ·ｇ－１,是一种良好的吸水剂。     

多孔淀粉的研究进展

多孔淀粉是一种新型的变性淀粉，作为吸附材料，具有高效、无毒、安全等优点，引起了国内外有关专家和科研机构的关注和兴趣，被广泛研究开发用于食品、医药卫生、农业、日用化工等行业。综述了近年来多孔淀粉在制备、改性和应用等方面的基本研究成果和进展，以及存在的问题。     

专用复肥干燥剂的研究开发

针对尿素系掺混型复合肥水解潮湿、板结成块的现象,通过理论分析及实验,选择确定出一种适宜的专用复肥干燥添加剂。     

淀粉基降解塑料的研究进展

综述了国内外淀粉基降解塑料的研究和开发现状及淀粉表面处理技术,淀粉的细化和增塑、淀粉与聚合物的增容技术以及及降解塑料的加工性能,降解性能等当前重点研究内容,并讨论了降解塑料的应用及发展前景。     

淀粉基生物降解塑料吹膜工艺及性能研究

通过挤出吹膜的方法制备PBSA/TPS淀粉基生物降解塑料,研究了不同风环结构及吹胀比和牵引比对于吹膜及性能的影响。结果表明:双风口风环可以极大提高PBSA/TPS材料的吹膜膜泡稳定性,而随着吹胀比和牵引比的增大,薄膜的拉伸强度、断裂伸长率和耐撕裂力先增大再减小。     

淀粉基生物降解塑料吹膜工艺及性能研究

通过挤出吹膜的方法制备PBSA/TPS淀粉基生物降解塑料,研究了不同风环结构及吹胀比和牵引比对于吹膜及性能的影响。结果表明:双风口风环可以极大提高PBSA/TPS材料的吹膜膜泡稳定性,而随着吹胀比和牵引比的增大,薄膜的拉伸强度、断裂伸长率和耐撕裂力先增大再减小     

The starch grafted poly(l-lactide) and the physical properties of its blending composites

A new method of the surface modified starch (SM-St) by grafting reaction of the hydroxyl groups on the starch with l-lactic acid was developed. A novel biodegradable starch grafted copolymer, starch-g-poly(l-lactide) (St-g-PLLA), was synthesized in situ by the ring-opening graft polymerization of a l-lactide (LLA) monomer onto the surface of the SM-St granules in the presence of Sn(Oct)₂ as a catalyst. The PLLA grafting efficiency could reach as high as 64 wt%. The structure of St-g-PLLA was characterized by IR, DSC and WAXD. The good adhesion between the two components had been evidenced by SEM observations. The medium-resistance of St-g-PLLA and the mechanical properties of the PLLA composite blending with St-g-PLLA were much better than that of the PLLA/starch blending composite.     

复合淀粉胶黏剂研究进展

淀粉具有资源丰富、使用方便、价格低廉、无毒环保等优点,成为最具有开发潜力的胶黏剂之一.单纯的原淀粉胶黏剂,存在许多不足之处,需要通过生物、化学或者物理方式改性并与其他物质复合,才能满足各种需要.综述了淀粉胶黏剂的最新研究现状,特别是复合淀粉的研究近况,并对其发展态势进行展望,在提高淀粉胶黏剂耐水性、防潮、稳定性等方面仍...     

Chemical Zymogens: Specificity and Steroidal Control of Reactivation

Activating and masking enzymatic activity on demand is of the highest importance in nature. It is achieved by chemical interconversion of enzymes and the corresponding zymogens through, for example, proteolytic processing or reversible phosphorylation, and affords on-demand activation of enzymes, controlled in space and/or time. In stark contrast, examples of chemical zymogens are very few, and in most cases these are based on disulfide chemistry, which is largely indiscriminate as to the nature of the activating thiol. In this work, we address an outstanding challenge of specificity of reactivation of chemical zymogens. We achieve this through engineering affinity between the chemical zymogen and the activator. Additional, higher-level control over zymogen reactivation is installed in a nature-mimicking approach using steroidal hormones. Taken together, the results of this study take a step towards establishing the specificity of reactivation of synthetic, chemical zymogens. We anticipate that the results of this study will contribute significantly to the development of chemical zymogens as tools for diverse use in chemical biology and biotechnology.     

甘薯淀粉糖苷表面活性剂的合成及性能研究

以甘薯淀粉、乙二醇、长链醇(C8~10醇、C12醇、C12~14醇)为原料,在2 000 L反应釜中采用转糖苷法合成了系列淀粉糖苷类表面活性剂。该产品25℃时表面张力为32 mN/m左右,并且具有两个cmc值点,第一个cmc值点表面张力约为35 mN/m,第二个cmc值点表面张力为24~28 mN/m。保湿性优于丙三醇及其它市售保湿产品,12 h后失水率低于30%,24 h后失水率为33.35%。具有较好的稳泡性,一定的乳化性。红外、气相色谱表征,该系列产品为淀粉糖苷类表面活性剂。     

淀粉疏水改性技术的研究进展

综述了淀粉疏水改性技术的应用情况及淀粉基降解塑料的国内外研究现状,着重介绍了应用较为广泛的几种淀粉疏水改性技术的优缺点及其发展动向。     

Synthesis and properties of composites of starch and chemically modified natural rubber

A means is developed for forming polysaccharide-based composites with useful material properties through use of unmodified and chemically modified natural rubber latex (NRL). Starch was used as a model for polysaccharides. The NRL was modified by grafting with dimethylaminoethyl methacrylate (DMAEMA) to form a latex with cationic water-soluble polymeric ‘hairs’ of polyDMAEMA, which should form hydrogen bonds with starch. Starch solutions, containing 20% glycerol as a film-forming aid, and the modified NRL were mixed and films allowed to form. The unmodified latex acted only as filler in the starch films, but with modified NRL, the mechanical properties of the films were significantly altered. The elastic modulus was greatly decreased and strain at break greatly increased. The glass transition temperature increased from −48 °C to −32 °C, suggesting significant compatibilization. Freeze-fracture TEM micrographs indicate strong interactions between the surface of the modified NRL and starch. The polyDMAEMA chains are more hydrophilic than the starch, and the addition of grafted latex results in a 20° drop of the water contact angle of the formed film, and a 25% increase of the water absorption compared to the native starch; with unmodified NRL, the opposite effect was observed.     

淀粉/聚乙烯醇全降解缓释塑料薄膜的制备与性能研究

聚乙烯醇(PVA)溶解后与淀粉(St)共混,同时加入增塑剂丙三醇、交联剂甲醛,反应结束后将包膜液流延成膜。考察了m(St)∶m(PVA)、反应温度、丙三醇用量、甲醛加入方式、甲醛用量、反应时间对薄膜性能的影响,并表征了薄膜的结构。结果表明:当m((St)∶m(PVA)=7∶3、反应温度为90℃、w(丙三醇)=3%(占St、PVA、纯水质量之和的质量分数)、甲醛一次性加入、w(甲醛)=2%、反应时间为1 h时,制得的塑料薄膜拉伸强度、断裂伸长率较大,吸水率和透NH4+率均较低,共混体系的相容性好。     

淀粉基烷基多苷柠檬酸酯盐的合成与性能

以红薯淀粉烷基多苷、柠檬酸为原料,在三元酸的催化作用下通过酯化和中和反应合成了阴离子表面活性剂烷基多苷柠檬酸酯盐(APG-EC).考察了合成工艺条件,其较佳工艺条件为:m(红薯淀粉烷基多苷):m(柠檬酸)=4:1,真空度0.040 MPa,反应温度115℃,催化剂用量(为相对于淀粉烷基多苷中试产品和柠檬酸质量和的质量分数)1.0%.通过红外光谱分析确定了产物结构,并对物化性能进行了测定.结果表明:APG-EC的γcmc=31.9 mN/m,cmc=5×10-3g/L,HLB=18,在硬水中的平均稳定性以及差示稳定性分别为5和5 5 5.与红薯淀粉烷基多苷的性能进行对比,其抗硬水稳定性明显增强.     

Polyethylene-octene elastomer/starch blends: miscibility,morphology and mechanical properties

In this paper, polyethylene-octene elastomer (POE) and starch blends were studied. The compatibility beyween POE and starch was improved by adding polyethylene-octene/maleic anhydride graft copolymer (POE-MA) as compatibilizer. The compatibilization reaction was followed by FTIR spectra. The morphology of the blends was investigated using scanning electron microscopy (SEM). It was found that the size of the starch phase increased with an increasing content of starch for the blends. The addition of POE-MA can lower the size of the starch phase in the POE matrix, and this was due to the formation of an ester carbonyl function group by the chemical reaction between the anhydride groups and hydroxyl groups on starch. This was reflected in the mechanical properties of the blends, the addition of POE-MA compatibilizer can improve the mechanical properties of POE/starch blends. The thermogravimetric analysis of POE/starch blends was also conducted.     

Dispersing agents for cement based on modified polysaccharides

In this paper, starch and cellulose anionic derivatives are investigated with the objective to obtain new biodegradable dispersing agents for mortar and concrete mixtures. For that purpose, different starch and cellulose materials were partially depolymerized, giving limit-dextrins with DP_w 50-300 and level-off-DP (LODP) celluloses with DP_w 30-150. The subsequent hydroxyethylation, carboxymethylation, or sulfoethylation of these partially hydrolyzed polysaccharides occurred in 2-propanol, whereas the sulfation was carried out in dimethyl sulfoxide. The molecular weights of the samples were characterized by means of GPC, the chemical structure and functionalization pattern by means of NMR spectroscopy, and the rheological behavior of the sample solution was also determined. The dispersant products were tested as mortar and concrete admixtures. As a result, it could be shown that partially hydrolyzed and sulfoethylated amylomaize starch (70% amylose) provides the most efficient dispersing agent. The results were comparable to those of superplasticizers (i.e., polycarboxylate ethers).