自分层有机硅丙烯酸树脂的合成研究

采用两种不同的乳液聚合工艺,以反应性有机硅单体为原料进行自分层有机硅改性丙烯酸酯乳液的合成研究。探讨了乳化剂以及有机硅种类、用量对乳液性能的影响,并对涂膜表面进行红外光谱及润湿性分析。结果表明:以乙烯基三甲氧基硅烷为单体,阴离子型乳化剂(十二烷基苯磺酸钠)和非离子型乳化剂(OP-10)作为复合乳化剂体系,采用种子乳液为基础的预乳化工艺制备的有机硅丙乳液性能稳定、成膜性优异。当有机硅用量为12g时,所得到的以有机硅丙烯酸树脂为主体的表层涂膜,具有较好的自分层效果,有利于实现自清洁作用。     

有机硅改性丙烯酸酯涂层胶的研制

选用有机硅氧烷与丙烯酸酯乳液共聚,讨论了反应温度、乳化剂、引发剂用量、硅烷偶联剂用量、功能性单体AA对聚合反应的影响,研究结果表明,有机硅氧烷与丙烯酸酯能很好的聚合,并且研制出的有机硅丙烯酸酯涂层胶具有优异的性能。     

有机硅改性丙烯酸酯粘合剂的研制

以八甲基环四硅氧烷（D4）与含有乙烯基的有机硅烷偶联剂聚合，制得有机硅氧烷乳液，该乳液再与丙烯酸酯单体发生共聚反应，得到有机硅改性丙烯酸酯粘合剂.讨论了各种因素对乳液聚合的影响，应用结果表明：改性丙烯酸酯粘合剂稳定性能良好，处理后织物手感柔软、滑爽、无游离甲醛释放，是一种集柔软剂和粘合剂为一体的多功能印染助剂.     

毛用亲水性有机硅柔软剂的合成及应用

用壬基酚聚氧乙烯醚(OP-10)作乳化剂,以十二烷基苯磺酸(DBSA)为催化剂,通过八甲基环四硅氧烷(D4)开环聚合,在一定条件下合成了阴离子有机硅微乳液.而后对其进行氨基、聚醚改性合成了毛用亲水性有机硅柔软剂.D4、OP-10、DBSA用量分别为微乳液质量的20%,4%～5%,3%～4%,60～70℃恒温反应5 h,预乳液滴加时间为1.5～2.0 h;改性剂用量为单体量的5%,聚醚、氨基改性剂质量比为1.5:1,反应温度为60～65℃,恒温反应2 h.合成的有机硅柔软剂为乳白半透明液体,略泛蓝光.结果表明,该产品不仅能使处理过的织物具有优良的柔软性和白度,并且还能赋予织物良好的亲水性.     

乙烯基硅油-丙烯酸酯共聚乳液的合成及性能

采用预乳化半连续滴加工艺,以丙烯酸为功能单体,丙烯酸丁酯、丙烯酸异辛酯和苯乙烯为主单体,乙烯基硅油为改性单体,阴-非离子复合型可聚合乳化剂X为乳化剂,过硫酸钾为引发剂,羟乙酯为交联单体进行无皂乳液聚合,合成了无皂乙烯基硅油-丙烯酸酯共聚乳液.优化的乙烯基硅油-丙烯酸酯共聚乳液合成工艺为:预乳液滴加时间60 min,体系保温时间60 min,反应型乳化剂X用量0.8％,引发剂过硫酸钾用量0.8％,丙烯酸用量2.4％,乙烯基硅油用量12％.乙烯基硅油-丙烯酸酯共聚乳液用于涂料印花工艺,与纯丙烯酸酯黏合剂相比,前者耐干、湿摩擦色牢度及耐皂洗色牢度优良,手感有明显改善.     

有机氟防水剂的合成与应用

以丙烯酸十二氟庚酯(G04),甲基丙烯酸甲酯(MMA),丙烯酸丁酯(BA)为主要单体,脂肪醇聚氧乙烯醚AEO-9和十二烷基苯磺酸钠(SDBS)为复配乳化剂,过硫酸铵(APS)为引发剂,制备含氟丙烯酸酯共聚物.探讨了n(BA)∶n(MMA)、引发剂的种类及用量、乳化剂种类及用量、反应温度、反应时间等因素对含氟丙烯酸酯共聚物性能的影响,并将自制的含氟丙烯酸酯聚合乳液对棉织物进行整理,结果表明:当n(BA)∶n(MMA)=3∶2,APS用量0.6%,乳化剂为m(SDBS)∶m(AEO-9)=3∶2,用量6%,温度为75℃,预乳液滴加时间为3.5h,后续反应时间为1 h时,所制备的含氟丙烯酸酯共聚物具有良好的防水透湿性能.     

相反转法制备有机硅阴离子乳液

研究了八甲基环四硅氧烷(D4)的开环乳液聚合,讨论了温度、催化剂、乳化剂用量对反应速率、转化率及乳液稳定性的影响,优选的制备条件为:在复配乳化剂质量比m(SDBS)∶m(OP-10)为3∶2~1∶1、用量为1%~2%(对单体质量,下同)时,通过相反转法对D4进行预乳化,采用连续聚合法得到了固体质量分数为40%、带蓝光半透明、无“漂油”的有机硅阴离子乳液.     

紫外光固化硅丙树脂皮革涂饰剂的研究

十二烷基硫酸钠为乳化剂,80℃条件下,m(有机硅预聚体)∶m(丙烯酸酯单体)=4∶50进行共聚,得到有机硅改性丙烯酸树脂乳液。降温至40℃,加入3%光聚合单体和3%光引发剂184(两者用量分别基于丙烯酸酯单体总质量和光聚合单体质量),搅拌0·5h,得到可紫外光固化硅丙树脂乳液。薄膜经过紫外光照射后,断裂伸长率达到367%,抗张强度达到19·3MPa,吸水率为32·2%,玻璃化温度转变点为-45·7℃。     

环氧基有机硅微乳液的制备与性能

采用乳液聚合法，由D4开环聚合、硅烷偶联剂KH560共聚改性制得透明的环氧基改性有机硅微乳液。讨论了反应温度、保温时间、催化剂用量与单体转化率的关系及乳化剂用量、滴加时间对乳液透光率的影响。应用结果表明，用该助剂处理后的织物具有优良的弹性回复性能和手感。     

有机硅改性丙烯酸树脂/无机纳米复合材料的合成研究

采用乳液聚合法 ,选用种子乳液的分步加料方式合成有机硅改性丙烯酸乳液。有机硅氧烷种子乳液与丙烯酸酯类进行聚合反应 ,与纳米级材料复配形成稳定的共聚乳液 ,制成的皮革涂饰剂具有优异的阻燃性、强度和韧性等综合性能。     

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