反应性乳化剂在滤纸增强乳液树脂中的应用研究

采用苯乙烯和丙烯酸酯类单体为主要聚合单体,SR-10为阴离子型反应性乳化剂,以过硫酸铵（APS）为引发剂制备无皂苯丙乳液。通过FTIR对共聚物的结构进行表征,其结果显示,可聚合型乳化剂参与了苯乙烯、丙烯酸酯单体的共聚反应。其次,将自制无皂苯丙乳液和常规苯丙乳液用于滤纸原纸的浸渍增强研究,研究结果表明,经无皂苯丙乳液增强的滤纸透气度、力学性能与选用常规苯丙乳液增强的滤纸相近,但前者增强后的滤纸具有较高的憎水性能。     

一种阻燃性空气滤纸的研制

本论文主要对空气滤纸的阻燃处理和苯丙乳液浸渍处理进行了探讨。选用的纤维原料为丝光浆、针叶木浆和聚丙烯纤维,其绝干量比为40∶40∶20,针叶木浆的打浆度选为30°SR,经质量分数为4%的阻燃剂溶液浸渍后,再经过固含量为4%的苯丙乳液固化,所得空气滤纸的最大孔径为37.20μm,平均孔径为10.95μm,最小孔径为3.27μm,透气度为130L/(m2.s),滤纸的续焰时间和灼焰时间都为0s,炭化长度为4m m。可见,滤纸具有一定的阻燃性能,且其他物理强度也都满足行业标准QB/T 4031-2010。     

三聚氰胺甲醛树脂在阻燃型空气滤纸中的应用

采用磷系阻燃剂制备内燃机用阻燃型空气滤纸,并用三聚氰胺甲醛树脂替代部分苯丙乳液进行增强,研究其对阻燃剂用量的影响.结果表明,15％的三聚氰胺甲醛树脂和85％的苯丙乳液进行复配后,阻燃剂的留着率在14％时即可获得优异的阻燃性能,可节约22％的阻燃剂用量,且不会降低滤纸的力学性能.     

交联型醋丙乳液用于汽车滤纸的增强

使用共聚和交联共用的方法对汽车滤纸用醋丙乳液增强剂进行改性,研究了体系中甲基丙烯酸甲酯(MMA)、丙烯酸(AA)、N-羟甲基丙烯酰胺(NMA)和三聚氰胺甲醛树脂(MF)用量对浸渍后滤纸强度性能的影响。结果表明,在MMA用量20%(质量分数,下同)、AA用量3%、NMA用量5%、MF用量4%时,改性醋丙乳液可赋予滤纸优良的强度性能,同时保持滤纸优良的孔隙结构和透气性。     

三聚氰胺甲醛树脂在阻燃型空气滤纸中的应用

华南理工大学制浆造纸工程国家重点实验室洪莉等人,采用磷系阻燃剂制备内燃机用阻燃型空气滤纸,并用三聚氰胺甲醛树脂替代部分苯丙乳液进行增强,结果发现,15％的三聚氰胺甲醛树脂和85％的苯丙乳液进行复配后,阻燃剂的留着率在14％时即可获得优异的阻燃性能,可节约22％的阻燃剂用量,且不会降低滤纸的力学性能。     

废纸造纸废水中细小纤维回用的实验研究

以废水经斜筛和气浮池回收的纤维为原料配抄瓦楞原纸和纸管原纸,分析了回收纤维的纤维形态特征,研究了回收纤维对成纸质量的影响规律。结果显示,斜筛和气浮池回收纤维中细小纤维占纤维总量的比例分别为38.5%和97.3%。抄制瓦楞原纸和纸管原纸时,成纸强度均随回用纤维量的增加而下降。以斜筛收集的纤维配抄瓦楞原纸时,其回用量以不超过6%为佳,而以气浮池收集的纤维配抄纸管原纸时,回用量不能超过8%。     

提高耐火隔热纸成纸强度的研究

针对硅酸铝纤维抄造过程中难成纸或者成纸强度低的问题,选用合适方法及对其进行表面处理。可达到提高成纸强度的目的。经实验得出选用胶粘剂水玻璃,可抄造出高强度耐高温的纤维纸张,其用量以20％为佳,抄造过程中浆料pH值以6．0左右为宜;与植物纤维配抄后能很好地提高纸页强度,添加增强剂PAE、CMC后能够降低植物纤维的用量;纤维经酸碱等化学方法表面处理后,增加了硅酸铝纤维之间的粘连和摩擦效果。     

醋丙乳液交联体系对汽车过滤纸湿强度性能的影响研究

使用交联单体甲基丙烯酸(MAA)和N-羟甲基丙烯酰胺(NMA)以及乳液体系加入外交联剂三聚氰胺甲醛树脂(MF)的方法提高树脂的交联度,研究了交联体系对醋丙乳液浸渍后过滤纸湿强度性能的影响。结果表明,乳液体系中引入交联体系可以有效增强浸渍滤纸的强度性能。在MMA用量为20%(wt)、MAA用量为3%(wt)、NMA用量为4%(wt)、MF用量为4%(wt)时,改性乳液的耐水性能增强明显,湿老化后滤纸的耐水保持率超过65%。     

细菌纤维素纤维对纸张增强作用的研究

介绍了细茵纤维素的合成机理,相关特性以及对纸张的增强机理.研究了细菌纤维素湿膜经机械匀浆处理所得的细菌纤维与植物纤维混合抄片的纸页性能.研究发现:细菌纤维配抄植物纤维,当细菌纤维素的用量为5%时,纸张耐折度提高44.7%,耐破指数提高17.9%,抗张指数提高22.4%,撕裂指数提高16.1%.     

丝光浆对空气滤纸原纸性能的影响

在室温条件下,对漂白硫酸盐针叶木浆进行丝光化处理,探讨了碱液浓度和处理时间对纸浆聚合度的影响;并进一步研究了丝光浆与针叶木浆的配比、针叶木浆的打浆度、增强剂种类和用量以及压榨和干燥方式对空气滤纸原纸性能的影响。结果表明,碱液浓度190 g/L、处理时间45 min时,获得的丝光浆具有较高的聚合度;另外,当丝光浆用量为50%、针叶木浆的打浆度为22°SR、阳离子聚丙烯酰胺用量为0.06%时,所抄空气滤纸原纸经压榨干燥后,其透气度高于100 μm/（Pa·s）,优于行业标准QB/T 4031—2010阻燃性汽车空气滤纸要求。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

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