三聚氰胺乙二醛树脂涂布抗水剂的制备及应用

以三聚氰胺、乙二醛为原料,制备了高固含量的三聚氰胺乙二醛树脂(MG),研究了其作为涂布抗水剂的作用机理。通过红外光谱(FT- IR)、扫描电镜(SEM)和纸张物理性能的检测对MG的结构、抗水剂的应用性能进行了表征。实验表明,以质量分数为2.0%的MG进行涂布时,可使纸张的湿强度和表面强度分别达到22.2%和2.90 m/s,油墨吸收率为47%。MG与淀粉复配具有极好的交联和相容性,纸张的湿强度随着m(MG):m(淀粉)的增大而增大,白度随m(MG):m(淀粉)的增大而减小。经MG处理后的纸样,纤维编织得更加紧密。     

三聚氰胺乙二醛抗水剂对涂布纸性能的影响

以二聚氰胺、乙二醛为原料,制备了用于涂布的三聚氰胺乙二醛(MG)抗水剂;采用X射线衍射分析对产物结构进行了表征,研究了MG对涂布纸性能的影响;初步分析了MG对涂料的流变行为的影响;通过扫描电镜(SEM)观察了纸张表面及断面的微观结构.结果表明,随着MG用量的增加,纸张的抗张强度增大,耐破度先增人然后略有下降,纸张的湿强度大幅增加,而白度随MG与淀粉质量比的增大而减小.当MG用量与淀粉用量的质量比为0.2～1.0时,涂料的触变性随着MG的添加先增大后减小.SEM结果显示,经MG处理的纸样,纤维结合的更加紧密.     

甘油环氧树脂改性聚乙烯亚胺纸张增强剂的制备及应用

通过水溶性甘油环氧树啮（GE）对聚乙烯亚胺（PEI）进行改性,制备出了具有强反应活性的改性聚乙烯亚胺（PEI）纸张增强剂。考察了交联剂用量、次陛物添加量、助留剂等因素对纸张强度的影响。并用SEM对其纸样微观结构进行了表征。实验结果表明,当w（GE）=17％、w（CPAM）=0．02%．良性PEI添加量为1％时,纸张湿强度达到22．84％,纸张耐折度提高10％以上。Zeta电位分析表明,当w（GE）=17％、改性PEI添加量为1％时,浆料电荷趋于零。SEM对纸样微观结构分析表明,纸张断裂是由纤维断裂引起的,为改性PEI可增加纤维间的结合强度提供了依据．     

接枝-氧化-酯化涂布淀粉黏合剂的制备

以KMnO4／H2C2O4为引发剂,水为分散介质,玉米淀粉与丙烯酸乙酯接枝聚合后,再经氧化酯交换反应制备了涂布淀粉黏合剂,并经IR光谱、DSC图谱、NMR波谱确认了接枝共聚物。研究了工艺条件对接枝参数及乙酰基含量的影响,确定了较佳的制备工艺：m（KMnO4）：m（H2C2O4）=1：2．5,w（引发剂）=0．35％,接枝反应温度为38℃,接枝反应时间为2h,酯交换反应温度为35～40℃,反应时间为3h,m（Na2CO3）=3g。以此黏合剂替代质量分数为60％丁苯胶乳用于低定量涂布纸涂布,其成纸各项指标均达到GB／T10335．2-2005合格品要求。     

涂布抗水剂的制备及应用

在淀粉—胶乳配方中，淀粉及其衍生物难以获得较好的抗水性。因此，为了提高涂布纸的抗水性能以适应高速印刷的工艺要求，必须施加抗水剂来解决。在类型众多的抗水剂中，改性三聚氰胺甲醛树脂特别适宜于车速快、高干燥温度的涂布，并使涂布纸具有较好的耐湿摩擦性能，在淀粉、蛋白质、聚乙烯醇和合成胶乳的涂料中效果良好。以下简述该产品的制备及应用。1〓涂布抗水剂的制备1.1云反应原理云南涂布抗水剂的制备分为2步：第1步是加成反应，在碱性条件下甲醛与三聚氰胺羟甲基化；第2步在酸性条件下进行醚化反应。1.2云合成技术路线3.1.1云南云…     

改进型造纸用抗水剂

最近由武汉现代工业技术研究院研制成功的改进型造纸用抗水剂在浙江投产成功 ,并且经用户使用后 ,一致反应效果良好。改进后的抗水剂不仅原材料成本比改性三聚氰胺抗水剂降低1 5 % ,而且缩短反应过程约 3小时 ,大大节约了生产成本和能耗 ,据了解该产品的生产工艺目前国内尚属首创。改进型抗水剂能与蛋白质胶粘剂、淀粉类胶粘剂相交联 ,同时也能进行自交联形成具有良好抗水性能的薄膜 ,因此可广泛应用于胶版印刷涂布胶 (铜版纸 )和涂布白板纸中 ,同时也可以用于纸张的表面施胶剂中 ,以提高纸张的表面强度和抗水性 (施胶度 ) ,降低纸张的伸缩…     

超低游离甲醛氨基树脂鞣剂DF-850的合成

以三聚氰胺、甲醛、甲醇为主要原料,三乙胺、苯酐为酸碱催化剂,尿素和硼砂为甲醛捕捉剂,合成一种水性的超低游离甲醛甲醚化氨基树脂鞣剂DF-850。根据测试结果表明：DF-850合成的最佳工艺配方为：n（三聚氰胺）：n（甲醛）：n（甲醇）=1：4：10,70℃～80℃碱性条件羟甲基化1．5h,50℃～60℃酸性条件下醚化缩合1h,该反应条件下制备的皮革鞣剂的贮存期达12个月,游离甲醛含量≤0．6％,固体分含量为60％-70％,能大幅改善复鞣填充的综合性能。     

两性壳聚糖的制备及其纸张增强性能研究

以CTS-ETA进行羧甲基化改性,制得两性壳聚糖,制备羧甲基化CTS—ETA的优化条件为：CTS-ETA／氯乙酸（质量比）=1．5：1,碱化时间为1n,醚化时间为5h,醚化温度为60℃,并将自制改性壳聚糖应用于纸张的增强。试验结果表明：两性壳聚糖可用作纸张的增强剂,加入少量（0．2％～0．3％）就能显著提高纸张的物理强度。     

热固性湿增强剂KH 560／PAE的制备及其对纸张的增强性能

制备了γ-环氧丙氧基丙基三甲氧基硅烷（KH 560）改性的PAE,讨论了其合成的影响因素;并采用羧甲基纤维素钠（CMC）作助留剂和改性PAE同时应用于纸张抄造。结果表明,n（NH2）：n（COOH）=1．05,n（EPA）：n（EPI）=1．5,w（KH560）=12％,合成温度为70℃,初始浓度为25％质量分数,此改性PAE反应过程易于控制,且有优良的湿强效果。     

水果套袋原纸专用高强抗水涂料研制成功

为解决国内大量使用废纸生产的水果套袋原纸抗水性、透气性与进口产品差距较大的现状,近期中国轻工集团造纸二次纤维利用协作中心成功研制了新型水果套袋原纸专用高强抗水涂料。该涂料采用进口原料生产,抗水指标达到国际同类产品水平,而价格只有国外产品的1/4。该产品涂布于原纸表面后只需加热到110～120℃以上,即可达到超强的抗水效果,而果袋纸产品的透气度与未涂布原纸相同,避免了使用石腊乳液胶降低透气度和加入明矾造成纸张发脆易老化的情况发生。果袋纸专用抗水剂使用高分子有机氟聚合物乳液,属纤维反应型抗水剂,涂布后的原纸不但可以…     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the