火焰喷涂尼龙1010和纳米石墨复合涂层的力学性能研究

采用电子万能实验机对火焰喷涂尼龙1010和纳米石墨复合涂层的力学性能进行了研究.结果表明:当m(尼龙1010):m(纳米石墨)=100:1时,涂层综合性能较好,涂层与基体(45#钢)的结合强度为42.96 MPa,涂层自拉伸强度为42.76 MPa,通过扫描电镜观察,涂层表面致密.     

低烟无卤阻燃电缆料的研制

以高密度聚乙烯(HDPE)与乙烯-醋酸乙烯共聚物(EVA)为基体材料,表面改性氢氧化镁为填料,红磷为阻燃剂,通过熔融共混的方法,得到了低烟无卤阻燃电缆料.研究了EVA/HDPE的不同配比、氢氧化镁及红磷的不同用量对材料力学性能和阻燃性能的影响.结果表明,当EVA/HDPE为3∶1,表面处理氢氧化镁用量为70份(以树脂100份计),阻燃助剂红磷8份,加工助剂6份时,所得到电缆料的物理机械性能和阻燃性能良好,可满足实际生产的需要.     

偶联剂对火焰喷涂超高分子量聚乙烯/石墨涂层力学性能的影响

在火焰喷涂超高分子量聚乙烯(UHMWPE)／石墨(G)复合涂层配方中采用了偶联剂TPM处理石墨技术，并利用拉力实验机及红外光谱测定仪等研究了TPM对复合涂层的宏观力学性能(如涂层与基体的结合强度、涂层自拉伸强度)及微观结构的影响。结果表明：偶联剂TPM的加入，使复合涂层的力学性能得到了明显改善，当m(TPM)：m(G)=2：100，m(UHMWPE)：m(G)=100：20时，复合涂层综合性能较好，涂层与基体的结合强度为6．82MPa，涂层自拉伸强度为32．79MPa。     

火焰喷涂尼龙1010/纳米TiO2复合涂层力学性能研究

利用电子拉力机探讨了纳米TiO2对火焰喷涂尼龙1010涂层力学性能的影响.结果表明,当复合涂层配比为m(尼龙1010):m(纳米TiO2)=100:0.5时,复合涂层综合性能较佳,涂层自拉伸强度为43.33 MPa,涂层与基体结合强度为40.23 MPa.纳米TiO2能够显著提高涂层力学性能.     

红磷阻燃增强PET/蒙脱土复合材料的研究

以PET/蒙脱土为基材树脂,通过添加玻纤、红磷阻燃剂、增韧剂等,制备出可在低模温下成型的PET/蒙脱土玻纤增强无卤阻燃工程塑料。研究了红磷阻燃剂、增韧剂对工程塑料性能的影响,结果表明,采用红磷阻燃体系,当添加量为16%时,能达到UL94-V0;在相同含量阻燃剂的情况下,随着增韧剂PTW含量的增加,复合材料的抗冲击性能逐步得到提高,复合材料的拉伸强度先随着增韧剂含量的增加而增加;当增韧剂含量达到2.5%之后,拉伸强度略有降低;复合材料具有良好的成型加工性等综合性能。     

火焰喷涂尼龙1010/纳米SiO2复合涂层的力学及老化性能

利用电子拉力机、紫外光辐照箱、示差扫描量热仪及扫描电子显微镜对火焰喷涂尼龙1010/纳米SiO2复合涂层的力学性能、耐老化性能及热性能等进行了测试.结果表明,当m(尼龙1010):m(纳米SO2)=100:1.5时,复合涂层综合性能较佳,自拉伸强度为69.8 MPa,与基体的结合强度为28.9 MPa;经10 d紫外线老化后,涂层自拉伸强度保持率为80.1%.纳米SiO2有明显的异质成核作用,使复合涂层的过冷度由27 ℃下降为24 ℃.表明纳米SiO2能够显著提高涂层力学性能和抗老化性能,并有助于提高复合涂层的结晶速率,具有明显的成核作用.     

腈纶的磷氮系膨胀型阻燃整理研究

以三异丙醇胺磷酸酯和三聚氰胺为原料,制备新型磷-氮膨胀型阻燃剂三异丙醇胺磷酸酯蜜胺盐(PTM),并对腈纶进行阻燃整理;以阻燃腈纶的垂直燃烧损毁炭长为指标,探讨原料质量比、阻燃剂质量浓度、焙烘温度、焙烘时间等因素对腈纶阻燃性能的影响。结果表明:较佳的原料质量配比:m(三异丙醇胺磷酸酯)∶m(三聚氰胺)=3.8;在阻燃剂质量浓度350 g/L、160℃的条件下焙烘2 min,阻燃腈纶的阻燃效果显著,火焰移开时自行熄灭,无熔融液滴,烟量小,损毁炭长为7.4 cm,达到国家标准B1级。     

以氢氧化镁为阻燃剂制备阻燃纸的研究

研究了以氢氧化镁为主的阻燃剂体系通过涂布加工工艺对纸张进行阻燃处理的阻燃效果.对所选用的阻燃剂(氢氧化镁、氢氧化铝、硼酸锌和微胶囊化红磷)进行有效组合,讨论了它们之间的协同作用,确定了有效的阻燃剂体系.结果表明,氢氧化镁、氢氧化铝、聚磷酸铵(APP)和红磷之间具有良好的协同作用;APP和红磷一样,都是添加量小但效果十分明显的增效阻燃剂;几种阻燃剂复配后纸张阻燃效果更好,续焰时间约为2.5s,续灼燃时间约为5s 炭化长度接近50 mm.     

涤纶窗帘布阻燃涂层整理工艺探讨

采用涂层法对涤纶窗帘布进行阻燃整理,探讨了非卤素环保型阻燃剂TEX-8或TEX-4(有机膦高聚物)与水性聚丙烯酸酯涂层胶的配伍性、比例以及阻燃涂层胶涂覆量对织物阻燃性能、断裂强力、手感的影响.研究表明:阻燃剂TEX-8与涂层胶混合后的稳定性较好,阻燃性能比TEX-4稍好,当m(阻燃剂TEX-8)∶m(涂层胶)=1∶1、涂覆量30 g/m2时,阻燃性能可达国家B1级标准,且对断裂强力和手感无明显影响.     

协效剂对棉杆皮聚乳酸复合材料力学性能的影响

在废弃棉秆皮纤维增强聚乳酸模压制成的复合材料板中添加阻燃剂后,由于其膨胀体系原理,严重影响了复合材料的力学性能.选用蒙脱土(MMT)和微纤化纤维素(MFC)作为协效剂,利用其特殊的物理结构来提高复合材料的力学性能.同时,蒙脱土也有协效阻燃作用,可以提高材料的阻燃性能.试验结果表明,在加入协效剂后,复合材料的力学性能均有提高,MFC对材料的拉伸强度和冲击强度提高较明显,可分别提高43.74%和41.50%.经XRD测定,加入MMT后,材料的片层间距增加到5.38 nm,说明MMT以片层的形式插入到纤维与基体中,同时极限氧指数增加了6.38%.     

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.     

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.