含氟单体接枝真丝的性能研究

研究了真丝经含氟丙烯酸单体改性后织物的拒水拒油性、机械性能等．结果显示接枝后丝织物的拒水拒油性能均优于未接枝的丝织物；其中经甲基丙烯酸六氟丁酯接枝改性的丝织物仅能获得较佳的拒水效果，而经甲基丙烯酸十二氟庚酯接枝改性的丝织物拒水拒油效果均较好。     

甲基丙烯酸八氟戊酯接枝真丝的结构和疏水性分析

为了研究含氟接枝改性剂改性处理对真丝纤维结构性能的影响,用含氟单体甲基丙烯酸八氟戊酯对真丝纤维进行接枝改性,并用红外光谱、偏光显微镜、扫描电镜、X光电子能谱、接触角测量仪对接枝后纤维的结构和疏水性进行了分析.结果表明:真丝纤维经接枝改性后,纤维表面附着了含氟聚合物,纤维直径增大且截面产生很多微孔,接枝后的蚕丝仍以β折叠链结构为主,接枝过程引起了分子平均取向度的下降;接枝后纤维的接触角明显增大,体现出较好的疏水性能.     

蚕丝的丙烯酸六氟丁酯接枝改性及拒水性能

采用含氟单体丙烯酸六氟丁酯,在引发剂过硫酸钾作用下对蚕丝进行接枝改性,研究单体和引发剂用量、改性温度和时间以及改性pH值等对蚕丝接枝率的影响。采用扫描电镜(SEM)和X射线光电子能谱(XPS)对接枝改性的蚕丝进行表征,并测试整理后蚕丝织物的物理机械性能及拒水性。结果表明,丙烯酸六氟丁酯对蚕丝接枝的优化工艺参数为:单体质量分数150%(omf),引发剂质量分数1%(owm),pH值3,反应时间120 min、反应温度75℃。接枝改性对蚕丝织物的白度、黄度、断裂强力和透气性影响较小,而表面张力下降明显,拒水性明显提高。     

甲基丙烯酸十二氟庚酯接枝蚕丝纤维的结构

采用扫描电镜、红外光谱、氨基酸分析、X射线衍射分析等测试手段,对甲基丙烯酸十二氟庚酯接枝蚕丝纤维的结构进行分析,探讨接枝改性前后蚕丝结构和性能的变化情况。分析结果显示含氟化合物单体甲基丙烯酸十二氟庚酯已接枝到蚕丝上,且接枝反应主要发生在蚕丝纤维大分子无定形区的酪氨酸(TYR)、精氨酸(ARG)、谷氨酸(GLU)等的反应性基团上,反映出纤维的结晶区未破坏,当接枝率较高时,纤维有一定损伤。     

反应型氨基硅油的制备

通过研究氨基硅油的合成、氨基硅油聚醚接枝工艺、氨基硅油异氰酸酯接枝工艺、残余异氰酸酯封端工艺等对合成速率及最终产品性能的影响,确定了合成聚醚异氰酸酯接枝氨基硅油即反应型氨基硅油的最佳合成工艺：聚醚改性剂用量24%（对氨基硅油质量）,反应温度75-85℃,反应时间3-4 h;异氰酸酯接枝70%（对氨基硅油中氨基含量）,反应温度55-70℃,反应时间2-4 h;残余异氰酸酯封端率65%,反应温度0-5℃,反应时间2-3h。     

反应型氨基硅油的制备

通过研究氨基硅油的合成、氨基硅油聚醚接枝工艺、氨基硅油异氰酸酯接枝工艺、残余异氰酸酯封端工艺等对合成速率及最终产品性能的影响,确定了合成聚醚异氰酸酯接枝氨基硅油即反应型氨基硅油的最佳合成工艺:聚醚改性剂用量24%(对氨基硅油质量),反应温度75~85℃,反应时间3~4 h;异氰酸酯接枝70%(对氨基硅油中氨基含量),反应温度55~70℃,反应时间2~4 h;残余异氰酸酯封端率65%,反应温度0~5℃,反应时间2~3 h。     

含羧基的支链链节结构对接枝改性羽毛蛋白上浆性能的影响

考察几种常用含羧基的乙烯基接枝单体对接枝改性羽毛蛋白浆料上浆性能的影响。在K2S2O8/NaHSO3氧化还原体系的引发下,将丙烯酸(AA)、甲基丙烯酸(MAA)及衣康酸(IA)单体分别接枝到天然羽毛蛋白的分子链上,制得接枝率相近而接枝支链分子结构不同的改性羽毛蛋白。然后采用3种接枝改性羽毛蛋白对纯棉经纱进行上浆实验,测试浆纱的增强率、减伸率、耐磨性和毛羽数量。结果表明,当选用AA作为接枝单体时,所得改性羽毛蛋白浆出的纱线性能较为优异。     

含聚丙烯酸酯支链的接枝田仁粉上浆性能

为将田仁粉(SG)浆料的纱线适用品种拓展至高比例含涤纱,考察常用丙烯酸酯单体的碳链长度对接枝改性田仁粉上浆性能的影响。采用Fenton试剂为引发剂,将4种具有不同碳链长度的丙烯酸酯单体分别接枝到天然田仁粉的分子链上,制得接枝率相近而接枝支链分子结构各有不同的改性田仁粉。然后,采用此系列接枝改性田仁粉对涤/棉(65/35)混纺纱进行上浆试验并测试浆纱的常用性能。结果表明：随着丙烯酸酯单体碳链长度的减小,所得接枝田仁粉浆出的涤/棉纱的断裂强力逐渐提高,断裂伸长率及毛羽数量则有所降低;以丙烯酸乙酯为接枝单体合成出的改性田仁粉浆纱的耐磨性最优。采用不同碳链长度的丙烯酸酯单体制备出的接枝改性田仁粉对高比例含涤纱上浆可满足织造工序对于浆纱不同方面的性能要求。     

亚麻短纤维接枝改性及其可纺性研究

以硫代硫酸钠和过硫酸铵的氧化还原体系为引发剂,丙烯酸为单体,对亚麻短纤维进行接枝改性,并用红外光谱进行了表征。研究反应温度、时间、引发剂用量及单体浓度对亚麻接枝率及单体接枝效率的影响。接枝后亚麻短纤维的分裂度提高204Nm,断裂强度降低1.27cN/tex。性能测试结果表明:丙烯酸接枝改性亚麻短纤维工艺对纤维损伤小,改善了亚麻短纤维的可纺性,纺纱性能提高。     

纳米微晶纤维素接枝含氟单体制备表面施胶剂的研究

以纳米微晶纤维素(NCC)为骨架,甲基丙烯酸六氟丁酯为单体,通过乳液接枝聚合合成新型表面施胶剂,并进行表面施胶的应用研究。考察乳化剂用量和含氟单体与NCC质量比对接枝率、接枝效率和单体转化率的影响;在较优条件下改性NCC接枝率、接枝效率、单体转化率分别为125.2%、27.7%、90.1%。通过红外光谱进行接枝前后NCC的官能团变化分析。通过纳米粒度仪分析了未改性/改性NCC的Zeta电位及粒径变化;结果表明,所得改性NCC在乳液体系中具有良好的稳定性;将其用于表面施胶,施胶处理后的纸张接触角能够达到120°,抗张指数较使用未改性NCC的纸张可提高26.4%,达到22.0 N·m/g。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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