无皂苯丙聚合物/AKD乳液表面施胶剂的制备与应用

以甲基丙烯酸(MAA)、苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,通过无皂乳液共聚反应制备了一种两性聚合物乳液表面施胶剂(ASAP)。以其为分散稳定剂制备了ASAP/AKD乳液表面施胶剂。以质量分数为0.15%的ASAP/AKD、质量分数为5%氧化淀粉表面施胶液,施涂量为1.2g/m2,对草木混合浆抄造纸张进行表面施胶,施胶度达113s。在ASAP/AKD乳胶质量分数为0.20%时,能显著改善纸张表面强度,耐折度、环压指数分别提高71.4%和40.7%。     

一种新型阳离子复合表面施胶剂的研制及应用

研制了一种新型阳离子复合(AKD-石蜡)表面施胶剂,考察了该施胶剂对瓦楞原纸的施胶效果。结果表明,自制新型阳离子复合表面施胶剂制备工艺简单;相同施胶量下与阳离子SAE施胶剂相比,新型阳离子复合表面施胶剂施胶纸的纵向环压指数、耐破指数和耐折度分别提高14%、8%和25%;当施胶量为2 kg/t纸时,与阳离子SAE施胶剂相比,表面施胶成本降低4元/t纸。     

阳离子含氟PUA表面施胶剂的制备及应用

为制备一种能够明显提高纸张施胶效果和印刷性能的聚合物表面施胶剂,以2,2,3,4,4,4-六氟丁醇甲基丙烯酸酯(FA)、苯乙烯(St)、丙烯酸丁酯(BA)为单体,在交联聚氨酯溶液(PU)中通过溶液聚合相转化法制得阳离子含氟聚氨酯-丙烯酸酯复合乳液(FPUA)表面施胶剂.用FT-IR、TEM和纸张物理性能检测的手段对聚合物结构、乳胶粒子形态以及应用性能进行了表征.实验结果表明,以质量分数为1.0%的FPUA进行表面施胶时,可使纸张的施胶度和拉毛速率分别达到9.50 s和2.80 m/s以上,油墨吸收率为26.0%～29.0%;乳胶粒子呈球形,其粒径约为230nm.     

PA-钠水玻璃复合表面施胶剂的应用

以无机盐固化剂PA和钠水玻璃为原料,制备了PA-钠水玻璃复合表面施胶剂,并对瓦楞原纸进行表面施胶处理.讨论了该复合表面施胶剂对瓦楞原纸环压强度、耐破度及抗水性能的影响,并分析了施胶后纸张的表面微观结构.与传统表面施胶剂相比,该复合表面施胶剂固含量高、黏度低,易于控制涂布量,涂层挺硬.将其应用于瓦楞原纸表面处理后,在双面施胶量9 g/m2时,纸张耐破指数比原纸增加了35％,环压指数是原纸的3.2倍.     

苯乙烯马来酸单辛酯共聚物乳液表面施胶剂的合成与应用

以苯乙烯、马来酸酐和马来酸单辛酯为原料,以过氧化苯甲酰为引发剂,在甲苯中进行共聚,经过沉淀分离、用氨中和后制备出苯乙烯-马来酸单辛酯-马来酸酐共聚物乳液表面施胶剂.采用GPC得到了苯乙烯-马来酸单辛酯-马来酸酐共聚物的分子质量,利用SEM观察了施胶纸张的表面情况,苯乙烯-马来酸单辛酯-马来酸酐共聚物对纸张进行表面施胶时,能提高纸张的施胶度和表面强度,施胶剂(玉米氧化淀粉与共聚物乳液的质量比为401)用量为1.-g/m2时,施胶度为9 s,抗张强度提高6.8%,耐破度提高10.1%,印刷表面强度为2.87 m/s,油墨吸收性为42%,应用实验表明该共聚物是一种高效的纸张表面施胶剂.     

磷石膏部分替代淀粉用作施胶剂的实验

主要研究磷石膏在造纸表面施胶剂中的应用。以磷石膏替代一定比例的表面施胶淀粉,用于瓦楞原纸表面施胶。实验表明:50%的磷石膏替代淀粉对原纸施胶后的环压指数为7.69 N.m/g,拉毛速度为2.29 m/s,加入0.3%AKD施胶后抗水时间为163.4 s,满足了瓦楞纸指标要求。磷石膏综合利用变废为宝,既降低造纸生产成本,又节约粮食资源。     

SMBD表面施胶剂的制备及应用

以马来酸酐和聚乙二醇2000为原料制备了反应型乳化剂马来酸聚乙二醇酯,然后以苯乙烯(St)、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,以马来酸聚乙二醇酯为乳化剂、以过硫酸钾为引发剂制备了SMBD表面施胶剂。以表面张力(γ)、临界胶束浓度(CMC)、傅里叶变换红外光谱(FT-IR)和透射电镜(TEM)进行了性能测试和结构表征。表面张力检测结果表明,马来酸聚乙二醇酯的CMC为0.26 g/L,γ为29.0 mN/m。FTIR分析表明SMBD表面施胶剂具有预期的共聚物结构,TEM分析表明SMBD表面施胶剂乳液微粒呈球形结构,微粒直径约70 nm。SMBD表面施胶剂胶膜耐水性明显强于十二烷基苯磺酸钠(SDBS)和壬基酚聚氧乙烯(10)醚(OP-10)作为乳化剂制备的表面施胶剂胶膜,15天后SDBS和OP-10作为乳化剂制备的表面施胶剂胶膜吸水率达44.2%,SMBD表面施胶剂胶膜吸水率仅为18.4%。采用SMBD表面施胶剂和氧化淀粉复配对未施胶轻型纸进行表面施胶,与市售某表面施胶剂和进口某表面施胶剂相比,SMBD表面施胶剂施胶纸张的Cobb值、表面强度、耐折度、撕裂指数和裂断长均优于该市售表面施胶剂,稍优于该进口表面施胶剂。     

有机硅表面施胶剂的制备及性能研究

在H2O2-FeSO4双组分氧化还原体系中,以酶改性淀粉为主链,以苯乙烯(St)、丙烯酸丁酯(BA)、丙烯腈(AN)、丙烯酰胺(AM)、二甲基二烯丙基氯化铵(DMDAAC)和γ-甲基丙烯酰氧基丙基三甲氧基硅烷为单体,通过自由基聚合制备了一种有机硅表面施胶剂。对其工艺条件进行了探讨,最佳工艺为:m(α-淀粉酶)∶m(绝干淀粉)=0.004,m(FeSO4)∶m(H2O2)=0.04,DMDAAC用量为有机硅表面施胶剂的0.6%,AN用量为有机硅表面施胶剂的1.5%,AM用量为有机硅表面施胶剂的0.4%,有机硅单体用量为有机硅表面施胶剂的2%,m(St)∶m(BA)=2,m(单体总量)∶m(淀粉)=2.4。通过红外光谱(FT-IR)、静态接触角和扫描电子显微镜(SEM)对其结构和性能进行表征。结果表明,有机硅表面施胶剂提高了瓦楞原纸的施胶性能,当有机硅表面施胶剂用量为表面施胶液的0.5%时,施胶效果达到最佳。     

核壳型氟化阳离子表面施胶剂的制备及应用

以苯乙烯、丙烯酸丁酯、甲基丙烯酸十二氟庚酯等为原料,不使用有机溶剂及乳化剂,采用自制阳离子聚合物为分散剂合成了核壳型氟化表面施胶剂(FAE).用IR、TEM、纸张物理性能检测等手段对聚合物结构、乳液粒子形态以及应用性能进行了表征.结果表明,以m(氧化淀粉):m(FAE)=85:15的施胶液进行表面施胶,当其施胶量为1.5 g/m2时,可使纸张的吸水性(cobb法)和表面强度分别达到29.9 g/m2和2.97 m/s,抗张指数和耐破指数分别达到58.8 N·m/g和2.76 kPa·m2/g.乳胶粒子呈球形,粒径分布均匀.     

苯乙烯马来酸酐共聚物乳液的合成与应用

以苯乙烯、马来酸酐为原料,以过氧化苯甲酰为引发剂,在甲苯中进行无规共聚,经过沉淀分离、改性制备出了苯乙烯马来酸酐共聚物乳液表面施胶剂。采用IR表征了苯乙烯马来酸酐共聚物的结构。利用SEM观察了施胶纸张的表面情况。结果表明,用苯乙烯马来酸酐共聚物对纸张进行表面施胶,能提高纸张的施胶度和表面强度,施胶剂用量为0.5g/m2时,施胶度为13s,抗张强度提高13.5%,耐破度提高16.0%,与淀粉、PVA复配均有明显的表面施胶效果。     

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