改性PAE树脂的制备及性能研究

采用羧甲基纤维素(CMC)对聚酰胺多胺环氧氯丙烷(PAE)树脂进行改性,以期在保持原有增湿强作用不变的前提下,提高PAE树脂的使用性能,并赋予其一定的增强性能,降低PAE树脂的使用成本。探讨了PAE树脂的改性工艺,并对改性PAE树脂进行傅里叶红外光谱表征,研究了改性PAE树脂对纸张的增强效果及对浆料Zeta电位、滤水性能的影响。结果表明,在PAE树脂成品中引入9%的CMC为最优改性工艺;在此工艺条件下制备的改性PAE树脂用量为0.6%时,浆料的滤水性能最优;在相同用量下(0.6%),与传统PAE树脂相比,添加改性PAE树脂所抄纸张的抗张指数提高约22%,湿抗张指数提高约19%,耐折度提高约13%,撕裂指数提高约5%,内结合强度提高约6%。     

羧甲基纤维素改性PAE树脂及其应用

该文研究了羧甲基纤维素（CMC）对聚酰胺多胺环氧氯丙烷（PAE）树脂的改性工艺,探讨了CMC改性PAE树脂的应用性能及改性后PAE树脂的动态流变特性.研究显示,经CMC改性后的PAE树脂,具有比传统PAE树脂更优异的性能.实验结果表明：CMC对PAE树脂的末端改性优于过程改性;CMC的较佳用量为9％（以改性PAE树脂质量计）;在此情况下,当改性PAE树脂用量为0.3％（以绝干浆质量计）时,与未改性的PAE树脂相比,纸张干抗张指数提高约8％,湿抗张指数降低约5％,耐折度提高约21％,撕裂指数提高约25％,内结合强度提高约48％.     

PAE树脂的改性及其应用

本文研究醚化改性剂对PAE树脂的改性工艺,探讨醚化改性PAE树脂的应用性能,研究显示经醚化改性后的PAE树脂具有比传统PAE树脂更优的性能。实验结果表明:醚化剂对PAE树脂的末端改性优于过程改性,醚化剂的较佳用量为15%;在此条件下改性后的PAE树脂用量为0.5%时,与改性前相比能够进一步提高纸张干抗张指数约3%,而降低湿抗张指数约19%,耐折度提高约9%,撕裂指数提高约19%,内结合强度提高约37%。     

羟基改性PAE树脂性能的研究

该文探讨了羟基改性剂聚乙烯醇（PVA）对聚酰胺多胺环氧氯丙烷树脂（PAE树脂）的改性方式、改性剂用量,并对改性PAE树脂进行表征,研究了改性PAE树脂的应用效果.实验结果显示,PVA对PAE树脂的末端改性优于过程改性,末端改性时PVA的最优用量为15％（以改性PAE树脂总固含量计）;改性后的PAE树脂具有较高的干增强性能及低的湿强性能,这样便于后续湿损纸的回收利用;采用末端改性工艺,在PVA用量为15％的情况下,当改性后的PAE树脂用量为0.5％（以绝干浆质量计）时,与原纸相比,能够进一步提高纸张干抗张指数约25％,湿强度增加约为11％,耐折度提高约136％,撕裂指数提高约44％,内结合强度提高约137％.     

PVA改性PAE树脂的制备及应用

探讨了羟基改性剂对PAE树脂的改性方式、改性剂用量,并对改性PAE树脂的增强性能进行分析。研究表明,羟基改性剂可以对PAE树脂进行改性,改性后不仅降低了PAE树脂的生产成本,还提高了PAE树脂的增干强效果。结果显示羟基改性剂对PAE树脂的末端改性优于过程改性;此时改性剂的较佳用量为15%;改性后的PAE树脂具有高的增干强性能及低的增湿强性能;当改性后的PAE树脂用量为0.5%时,与改性前相比,能够进一步提高纸张干抗张指数约7%,而降低湿抗张指数约23%,耐折度提高约13%,撕裂指数提高约25%,内结合强度提高约42%。     

醚化改性PAE树脂性能的研究

该文探讨了醚化改性剂对PAE树脂的改性方式和改性剂用量,并对改性PAE树脂进行表征,研究了改性PAE树脂的应用效果.结果显示：醚化改性剂可以对PAE树脂进行改性,改性后提高了PAE树脂的增干强效果;醚化剂对PAE树脂的末端改性优于过程改性;醚化剂的较佳用量为质量分数15％（对改性PAE树脂总固含量）;当改性后的PAE树脂用量为质量分数0.5％（对绝干浆）时,与改性前相比,能够进一步提高纸张干抗张指数约3％,而湿抗张指数降低约19％,耐折度提高约9％,撕裂指数提高约19％,内结合强度提高约37％.     

改性PAE树脂作纸张干强剂的研究

本文进行了PAE树脂的改性研究,以期用作纸张的干强剂。探讨了改性PAE树脂的制备及改性后的PAE树脂对浆料Zeta电位、留着、滤水的影响,同时对改性PAE树脂的增强性能进行了研究,并与阳离子淀粉的使用进行了比较。研究结果表明:利用羧基改性剂对PAE树脂进行改性后作为增强剂,改性PAE树脂用量为0.6%时,与1.0%阳离子淀粉增强作用效果基本相当;利用羧基改性剂对PAE树脂进行改性,羧基改性剂最佳引入量为9%;另外在PAE树脂成品中引入羧基改性剂改性,有利于PAE树脂成本的降低,也有利于损纸的回收。     

湿强剂在二次纤维配抄薄页包装纸中的应用研究

传统的薄页包装纸生产都采用原生漂白木浆,生产成本较高。采用二次纤维替代部分原生纤维在高速纸机上生产薄页包装纸,能够降低企业生产成本。本文研究了在添加80%的二次纤维情况下高速抄造薄页包装纸过程中湿强剂聚酰胺环氧氯丙烷树脂(PAE)的添加对纸张抄造和纸张性能的影响。结果表明:PAE的添加可以迅速降低浆料的溶解电荷和表面电荷,其最佳添加量为0.6%。在此用量下,浆料取得最低的保水性能和较好的抄造性能。此时浆料滤水性能最好,对湿纸抗张指数、湿纸拉伸积和成纸吸收指数提高效率最高。     

丙烯酸改性PAE树脂性能的研究

用丙烯酸对PAE树脂进行改性,以期替代传统PAE树脂作为纸张的增强剂。探讨了在PAE树脂中引入丙烯酸的改性工艺及其应用,同时对改性PAE树脂的增强性能进行了研究。研究结果表明:在PAE树脂成品中引入9%的丙烯酸为最佳改性工艺,在此工艺条件下制备的改性PAE树脂对纸张的增强效果最佳;当改性PAE树脂用量为0.6%时,与使用1.0%传统PAE树脂的增强作用效果基本相当;另外在PAE树脂成品中引入丙烯酸,有利于PAE树脂成本的降低。研究成果对改性PAE树脂的研究、开发及应用具有较强的参考价值。     

PAE/NCC二元体系对纸张的增强作用

研究了聚酰胺多胺环氧氯丙烷/纳米晶体纤维素（PAE/NCC）二元体系对不同浆料所抄造纸张的增强效果,讨论了PAE/NCC二元体系中NCC的最佳用量及加入方式。研究结果表明,先PAE后NCC的添加方式对纸张的增强效果好于PAE与NCC先混合后添加的方式 ;PAE用量为1.0%、NCC用量为0.6%、采用先PAE后NCC的添加方式时,对针、阔叶木混合浆纸张,与原纸相比,干抗张指数增加了42.9%,湿抗张指数增加了13.3倍,撕裂指数增加了24.3%,耐折度增加了89.7%;对阔叶木浆所抄纸张,干抗张指数增加了74.7%,湿抗张指数增加了18.8倍,撕裂指数增加了28.7%,耐破指数增加了115%,耐折度增加了5倍。     

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