AKD 改性聚氨酯预聚体共混物的制备及其中性施胶性能的研究

将烷基双烯酮二聚物(AKD)与羟基封端的聚氨酯预聚体反应,制备了一种末端为硬脂酰乙酸酯基的大分子施胶剂(SPU),使用N-甲基二乙醇胺作为扩链剂和阳离子化剂,使用硫酸二甲酯作为中和剂,增加其阳离子性,并使其具有较强的乳化和分散能力,能够对未参加反应的AKD进行有效地分散,得到稳定的流动性良好的施胶剂乳液;在中性条件下进行施胶,具有良好的留着性和施胶效果。当w(施胶剂)=0.2%时,施胶度可达到36 s,熟化后则达到53 s,证明所合成的中性施胶剂在中性条件下具有良好的留着性和施胶效果。上述中性施胶剂的合成条件为:m(扩链剂)∶m(SPU)=0.3∶1,m(硫酸二甲酯)∶m(SPU)=0.3∶1,Zeta电位值为20~40 mV。     

新型阳离子AKD施胶剂的制备及应用

研究了一种新型阳离子AKD施胶剂的制备及应用,将该阳离子AKD施胶剂与传统AKD施胶剂分别对阔叶木浆与草浆施胶,结果表明,在同等施胶条件下,阳离子AKD施胶剂的施胶性能均优于传统AKD施胶剂.由于阳离子AKD分子上接枝了具有高阳电荷的阳离子基团,故能更多地留着并定向排列分布在纤维表面上,因此比传统AKD施胶剂具有更好的施胶效果.     

阳离子双硬脂酸酰胺的制备及其在中性施胶中的应用

以单硬脂酸甘油酯、二乙烯三胺、硫酸二甲酯为原料,制备了自乳化的阳离子双硬脂酸酰胺施胶剂,并用其进行纸张中性施胶实验。结果表明,在反应温度125℃、反应时间2.5 h的条件下,制备的阳离子双硬脂酸酰胺乳液具有良好的留着性和抗水性;该施胶剂在中性条件下施胶效果良好,草浆抄纸时,用量为1.0%时施胶度超过14 s,木浆抄纸时,用量达到0.2%即可产生施胶效果;且该施胶剂对纸张纤维有疏松、增厚作用,施胶剂用量1.0%时,纸张柔软度可提高20%,厚度增加10%。     

BCTMP抄造白卡纸施胶及助留性能的研究

根据BCTMP浆料的物化特性，对助留剂及阴离子捕集剂在造纸湿部的助留助滤作用、AKD及阳离子松香胶的施胶性能进行了研究。结果表明：助留剂的用量与纸料的滤水时间及白水浊度成反比；阴离子捕集剂的使用对AKD施胶性能改善作用不明显；阳离子松香胶对BCTMP浆近中性施胶，在用量0．4％时施胶效果优于AKD用量0．5％的值。     

硼改性微粒硅溶胶的助留助滤试验

研究了剪切力和CPAM、阳离子淀粉、硼改性硅溶胶用量对硼改性硅溶胶与阳离子淀粉或CPAM组成不同助留助滤体系的助留助滤效果的影响;同时研究了硫酸铝用量、pH值及电解质用量对助留助滤效果的影响.研究结果发现:阳离子淀粉/硼改性硅溶胶微粒助留体系的抗剪切能力优于阳离子淀粉一元助留体系.阳离子聚合物/硼改性硅溶胶微粒助留助滤体系的助留助滤效果优于一元助留助滤体系,同时大大地改善了纸页的匀度.阳离子淀粉/硼改性硅溶胶微粒助留助滤体系在pH值4～8时,以及在松香施胶体系中硫酸铝用量≤3%时较为适用,该体系抗电解质干扰能力强.     

浅谈施胶度的影响因素

本文主要从胶料的用量、助留剂的使用情况、施胶顺序、系统地PH值、浆料和的种类这几个方面论述了阳离子分散松香胶和AKD中性胶的施胶影响因素。     

自留着型阳离子微粒乳化中性分散松香胶的研究

以苯乙烯、丙烯酰胺等为原料,采用乳液聚合工艺制备的阳离子共聚物型有机微粒,可在少量阳离子低分子表面活性剂的基础上,对松香/马来松香/松香甘油酯混合物起到良好的乳化与分散作用,所得胶料在助留剂用量为0.5%~0.7%范围内施胶效果良好,但自留着性有一定局限。有机微粒/阳离子聚酰胺多胺-环氧氯丙烷体系的阳离子微粒乳化中性分散松香胶具有低泡性及良好的自留着性能,在近中性条件下,所得胶料用量在0.5%~0.7%可获得良好的应用效果。     

阳离子无皂苯丙聚合物分散松香胶与AKD复配施胶剂的制备及性能

将松香、阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC),非离子单体丙烯酰胺(AM)、苯乙烯(St)及丙烯酸丁酯(BA),交联单体N-羟甲基丙烯酰胺(NMA)一次性投入,采用优化的工艺制备阳离子无皂苯丙聚合物,用该聚合物乳化分散逆转松香制得阳离子分散松香胶。在65℃搅拌下,向阳离子分散松香胶中加入18Wt%AKD(占松香)对其改性,得分散松香、AKD施胶剂。实验研究表明该乳胶具有优异的分散性和稳定性。施胶实验结果显示:在浆料pH值为6.5、助留剂CPAM为0.25%、分散松香胶与AKD用量为1.3%(占磨木浆)施胶时,施胶度达86s;填料GCC为15%～20%时,仍具有良好的施胶效果,可用于中性抄纸。     

水包水阳离子聚丙烯酰胺对AKD的施胶增效

AKD胶属中性施胶剂.在AKD应用过程中,AKD必须配合合适的助留剂才能发挥最佳的施胶效果,聚丙烯酰胺一直以来是作为助留剂的最佳选择.为了验证新型水包水阳离子聚丙烯酰胺(CPAM)的施胶增效效果,我们在一台生产油光纸的1760mm单圆网纸机上进行试验研究.     

阳离子无皂苯丙聚合物分散松香胶的制备及应用

采用阳离子无皂苯丙聚合物分散松香胶的优化制备工艺,将松香一次性投入,以DMC为自乳化阳离子单体,AM为亲水单体,St、EA为亲油单体,经氧化还原引发,借助于反应形成的阳离子无皂苯丙聚合乳液作分散乳化剂制得阳离子苯丙共聚物分散松香胶。该松香胶具有优异的施胶效果和稳定性,以CPAM为助留剂,矾土的用量明显降低,对磨木浆加入量为1％～1．2％时,施胶度迟72s,GCC填料为15％～20％时,仍具有较好的施胶效果,可适用于近中性抄纸体系。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.