无皂苯丙乳液表面施胶剂的制备与表征

以芬顿试剂为引发剂,阳离子淀粉为主链,苯乙烯(St)、丙烯酸丁酯(BA)、丙烯酸羟乙酯(HEA)和甲基丙烯酸二甲基氨基乙酯(DM)为单体,采用无皂乳液聚合法在阳离子淀粉分子上接枝苯丙共聚单体,合成出一种无皂苯丙乳液表面施胶剂,并通过傅里叶变换红外光谱仪(FT-IR)、粒径分析仪、静态接触角和扫描电镜(SEM)对乳液的结构和性能进行了表征。结果表明:当m(单体总量):m(淀粉)=2:1,m(H2O2)=2.6%,m(St)/m(BA)=2.5,m(HEA)=0.3%,m(DM)=1.2%,表面施胶剂用量为0.4%时,施胶效果最佳。     

环氧树脂阳离子无皂苯丙乳液用于纸张的表面施胶

以丙烯腈改性淀粉为分散剂,苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸二甲基氨基乙酯(DM)为单体,丙烯酰胺(AM)为交联单体,环氧树脂(E-44)为功能单体,过硫酸钾(K2S2O8)为引发剂,采用无皂乳液聚合技术合成了一种阳离子苯丙乳液表面施胶剂,并对文化纸进行表面施胶。最佳合成工艺是:w(DM)=3%,m(St):m(BA)=3,w(AM)=4%,w(E-44)=0.3%,w(K2S2O8)=0.5%。     

PVA接枝共聚物乳液表面施胶剂的研究

以PVA为主链,丙烯酸(AA)、苯乙烯(St)、丙烯酸丁酯(BA)为单体,通过直接滴加方式制备了一种无皂乳液表面施胶剂。讨论了反应条件的变化对乳液稳定性及施胶应用效果的影响,确定了较佳的合成条件为:m(AA)∶m(St)∶m(BA)=4∶12∶9,w(KSP)=2.5%,反应温度80℃,反应时间6h。在原料相同的情况下,用直接滴加方式制得的PVA接枝乳液和利用核壳技术制得的苯丙乳液进行了理化性能和施胶性能的对比,结果发现,PVA接枝乳液的乳胶平均粒径比核壳苯丙乳液的小,且施胶效果明显比核壳苯丙乳液的好。     

环氧树脂作功能单体阳离子苯丙乳液表面施胶剂的研究

以丙烯腈改性淀粉为分散剂,苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸二甲基氨基乙酯(DM)为单体,丙烯酰胺(AM)为交联单体,环氧树脂(E-44)为功能单体,过硫酸钾(K2S2O8)为引发剂,采用无皂乳液聚合技术合成了一种阳离子苯丙乳液表面施胶剂,并对施胶纸张各种性能作了测试。最佳合成工艺是:w(DM)=3%,m(St):m(BA)=3,w(AM)=4%,w(E-44)=0.3%,w(K2S2O8)=0.5%,与国内某产品对比,施胶度提高了15%,环压强度提高了18%。     

松香胺作功能单体阳离子无皂苯丙乳液表面施胶剂的研究

以丙烯腈改性淀粉作分散剂,苯乙烯（St）为硬单体,丙烯酸丁酯（BA）为软单体,松香胺（RA）为功能单体,甲基丙烯酸二甲基氨基乙酯（DM）为阳离子单体,丙烯酰胺（AM）为交联单体,过硫酸钾（K2S2O6）为引发剂,采用无皂乳液聚合技术合成了一种阳离子苯丙乳液表面施胶剂,并对施胶纸张各种性能做了测试。最佳合成工艺是：m（St）／m（BA）=2．5,w（RA）=0．5％,w（DM）=0．9％,w（AM）=0．4％,w（K2S2O8）=0．5％,m（单体）／m（淀粉）=2。     

单体比例对苯丙乳液表面施胶剂性能的影响

以苯乙烯(St)为硬单体,丙烯酸丁酯(BA)为软单体,丙烯酸(AA,用量为单体总质量的5%)为功能性交联单体,合成了苯乙烯丙烯酸酯(SAE)聚合乳液,并将SAE聚合乳液与氧化淀粉复配(SAE聚合乳液的添加量为氧化淀粉绝干质量的5%)对纸张(牛皮箱纸板,定量130 g/m2)进行表面施胶。探讨了单体比例(m(St)∶m(BA))对SAE聚合乳液玻璃化转变温度及稳定性的影响。结果表明,SAE聚合乳液的玻璃化转变温度随硬单体用量的增加呈线性上升,并且与采用L.Mandelkern方程计算的结果具有较好的一致性;SAE聚合物分子质量和乳液表观黏度随硬单体用量的增加均逐渐降低,乳液稳定性略有下降。与只用氧化淀粉施胶后的纸张相比,在相同涂布量下,经SAE表面施胶剂施胶后的纸张的Cobb值低,印刷表面强度和耐破度均有不同程度提高;当m(St)/m(BA)=80∶20时,经SAE表面施胶剂施胶后纸张的Cobb值降低了51.8%,印刷表面强度和耐破度分别提高了58.0%和5.2%。     

明胶/自交联苯丙聚合物的制备及其表面施胶性能

以N-羟甲基丙烯酰胺(NMA)作自交联单体,明胶(Gel)为高分子分散稳定剂,苯乙烯(St)和丙烯酸丁酯(BA)为单体,采用无皂种子乳液聚合制备了稳定的自交联苯丙乳液,并优化了合成工艺条件。研究表明:当w(Gel)=32%,软硬单体比例n(BA)/n(St)=2∶1,w(NMA)=4%时,自交联苯丙乳液具有优异的施胶效果,当以质量分数为1%的聚合物乳液进行表面施胶时,纸张施胶度可达52.0 s,环压指数达5.9 N/m/g,耐折度13次;环压指数和耐折度分别比空白样提高了23%和62.5%。     

阳离子含氟苯丙共聚物表面施胶剂的制备及应用

在氧化还原体系中,以淀粉为主链,苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸十二氟庚酯(FM)、N-羟甲基丙烯酰胺(HMAM)和二甲基二烯丙基氯化铵(DMDAAC)为单体,通过无皂乳液聚合制备了阳离子含氟苯丙共聚物瓦楞纸表面施胶剂,并通过红外光谱(FT-IR)、静态接触角和扫描电镜(SEM)进行了表征。结果表明,最佳合成工艺是:m(单体):m(淀粉)=2,m(St):m(BA)=2.5,m(过硫酸钾):m(淀粉)=0.5,w(FM)=0.3%。当施胶浓度为0.6%时,施胶度可达5min。     

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。     

乙二醛改性淀粉基苯乙烯丙烯酸酯乳液的制备及其表面施胶性能

利用低黏度阳离子淀粉(CS-8)的乳化、分散作用,采用无皂乳液聚合的方法,以苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)和甲基丙烯酸二甲基氨基乙酯(DM)为主要原料,合成核壳型阳离子苯乙烯丙烯酸酯乳液(SAE),并引入乙二醛对淀粉基SAE进行改性。讨论了制备条件对乳液性能和施胶性能的影响,并对乙二醛改性SAE与未经乙二醛改性SAE、商品苯丙乳液8906的表面施胶性能进行了比较。实验结果表明:当w(CS-8)=8%,m(St)/m(BA)=9:11,w(乙二醛)=10%时,所制SAE乳液性能优异,施胶效果良好。添加乙二醛对淀粉基SAE进行改性提高了乳液对纸张憎水性能和物理强度的改善作用,其施胶效果优于商品苯丙8906。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press