阳离子型含氟丙烯酸酯表面施胶剂的制备及应用

以甲基丙烯酸十二氟庚酯(FM)、丙烯酸丁酯(BA)、苯乙烯(St)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)、丙烯酸十八酯(ODA)为原料,采用无皂乳液聚合制得了阳离子含氟丙烯酸酯多元共聚物乳液.单独使用含氟乳液对纸张进行表面施胶,水和油滴在纸张上所成的接触角最大可分别达到121°和80°;将淀粉和含氟乳液以不同质量比复配应用,讨论了复配体系对纸张防水防油性的影响.     

改性苯乙烯-丙烯酸酯胶乳表面施胶剂的合成及研究

以甲基丙烯酸十二氟庚酯（FM）、丙烯酸丁酯（BA）、苯乙烯（St）、甲基丙烯酰氧乙基三甲基氯化铵（DMC）、丙烯酸十八酯（ODA）为原料,采用无皂孔液聚合制得了阳离子含氟丙烯酸酯改性的苯乙烯-丙烯酸酯（SAE）乳液。对聚合物的结构、组成进行了表征,并研究了引发剂、FM的用量对乳液耐水性和稳定性的影响。单独使用含氟乳液对纸张进行表面施胶,水和油滴在纸张上所成的接触角最大可分别达到121°和80°,同时纸张的抗张强度、耐折度,白度、平滑度分别提高11．36％、7．14％、0．25％、50．48％。由于使用的阳离子化试剂是季铵盐型,所以可适用广泛pH值范围,可同时应用于酸性施胶、碱性施胶和中性施胶。     

含氟丙烯酸酯乳液表面施胶剂的制备与应用

以甲基丙烯酸六氟丁酯(FMA)、醋酸乙烯酯(VAc)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)为单体,采用种子乳液聚合法制备了一种能够明显提高纸张施胶效果的含氟聚丙烯酸酯乳液。分析了FMA用量对该乳液的性能影响,测定了乳胶膜的对水接触角和吸水率。试验结果表明,用含氟聚丙烯酸酯乳液与淀粉复配进行表面施胶,当其施胶量为1.5g/m2时,可使纸张表面强度增强的同时大大提高纸张的施胶度。     

苯乙烯/丙烯酸酯乳液对表面施胶性能的影响

对苯乙烯／丙烯酸酯乳液在纸张表面施胶中的应用效果进行了研究。结果表明,对纸厂原纸进行表面施胶时,加入苯乙烯／丙烯酸酯乳液,能显著提高纸张抗水性、纸张强度和表面强度,且对纸张白度影响不大。     

几种不同施胶剂施胶性能对比

用改性胶原蛋白乳液、苯丙乳液和AKD乳液三种胶液对瓦楞原纸进行表面施胶,对比考察三种施胶剂施胶后纸张的力学性能及吸收性变化。将改性胶原蛋白乳液与苯丙乳液进行复配施胶,当两者的比例为1：1时,此时纸张的各项性能最好,与未施胶纸样相比,纸张的抗张指数、环压指数分别提高了63.4%和79.2%,Cobb60降至40 g/m2。改性胶原蛋白乳液与AKD乳液复配施胶,两者的比例为3：1时,纸张的各项性能最好,纸张的环压指数、抗张指数分别提高了54.2%和47.7%。纸张Cobb60值则降为34.7 g/m2。将三种胶液与淀粉复配,或者两两复配施胶,其中以改性胶原蛋白乳液与苯丙乳液复配后效果为最佳。     

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.     

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%。     

有机硅烷改性自交联聚丙烯酸酯微乳液的制备与纸张表面施胶性能

采用无皂乳液聚合,以甲基丙烯酸甲酯(MMA),丙烯酸丁酯(BA),丙烯酸(AA),丙烯酸羟丙酯(HPA)等为原料,γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH570)为硅烷交联剂,制备了一种稳定的阴离子型聚丙烯酸酯微乳液,其可作为表面施胶剂用于纸张表面增强处理。讨论了KH570用量对乳液及施胶纸张性能的影响。结果表明,有机硅氧烷单体成功的键接到丙烯酸酯聚合物上,且当ω(KH570)=1.78%(质量分数,下同)时,乳液综合性能佳且其施胶效果好,乳液粒径低至45.80nm。表面施胶后的纸张强度有明显提升,干湿强度分别提高26.5%、27.1%,耐折度提高332.4%,施胶度提高49.85%,纸张水滴接触角可由35.2°增加至59.1°。     

有机氟防水剂的合成与应用

以丙烯酸十二氟庚酯(G04),甲基丙烯酸甲酯(MMA),丙烯酸丁酯(BA)为主要单体,脂肪醇聚氧乙烯醚AEO-9和十二烷基苯磺酸钠(SDBS)为复配乳化剂,过硫酸铵(APS)为引发剂,制备含氟丙烯酸酯共聚物.探讨了n(BA)∶n(MMA)、引发剂的种类及用量、乳化剂种类及用量、反应温度、反应时间等因素对含氟丙烯酸酯共聚物性能的影响,并将自制的含氟丙烯酸酯聚合乳液对棉织物进行整理,结果表明:当n(BA)∶n(MMA)=3∶2,APS用量0.6%,乳化剂为m(SDBS)∶m(AEO-9)=3∶2,用量6%,温度为75℃,预乳液滴加时间为3.5h,后续反应时间为1 h时,所制备的含氟丙烯酸酯共聚物具有良好的防水透湿性能.     

含氟丙烯酸酯乳液用于纸张湿强剂的研究

研究了在未漂竹浆浆内添加含氟丙烯酸酯乳液时,助剂用量对手抄片的湿强度和抗水性能的影响.结果表明,在硫酸铝用量为2.8%,自制阳离子助剂(质量分数15%)及乳液(质量分数40%)用量分别为6.0%和8.0%时,能大大提高纸张的湿强度,纸张湿强度保留率可达44.8%,纸张吸水性(Cobb法)为18.8 g/m2.XPS分析显示纸张表面富集了氟元素,SEM测试表明含氟乳液对纤维表面包覆良好,因而赋予纸张优异的力学性能和抗水性.     

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