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1.
与传统的石油基油墨比较,大豆油基印刷油墨是一种环保型油墨,且具有良好的印刷适性,日益得到社会的承认.本文以我国资源丰富的大豆油为原料,以蒽醌为催化剂,对影响热聚合反应的因素:温度、时间和催化剂加入量进行了探讨.结果表明,生产大豆油基印刷油墨连结料的较好工艺条件是:热聚合温度为290~310℃,时间为1~3h,蒽醌加入量为底物质量的3%~7%,在此条件下可以制备出黏度范围较宽的热聚合油,满足印报用油墨连结料的黏度要求;蒽醌作为共轭化催化剂,毒性小,对产品酸价和色泽影响也较小,并且回收率在87.5%左右,可以重复利用数次,基本不影响使用效果.该研究为植物油基印刷油墨连结料的工业化生产提供了理论依据。  相似文献   

2.
对棉籽壳烧碱-蒽醌法蒸煮脱木素机理和棉短绒烧碱-蒽醌法蒸煮除尘工艺进行了研究,结果表明棉籽壳烧碱-蒽醌法蒸煮时,在升温至100℃时脱除34.57%的木素;当温度升到160℃时,木素的脱除率达到87.11%。因此,棉籽壳烧碱-蒽醌法蒸煮脱木素的阶段性可分为初始脱木素、主要脱木素和残余脱木素三个阶段。另外,影响棉短绒烧碱-蒽醌法蒸煮除尘的主要因素是用碱量,其次为蒸煮最高温度,影响最小的因素为保温时间。  相似文献   

3.
杜仲一年生枝条制浆性能初步研究   总被引:1,自引:0,他引:1  
研究了杜仲的化学成分及纤维形态学参数,结果表明,杜仲纤维素和半纤维素含量高、木素含量较低,纤维长宽比较大、壁腔比小,是良好的制浆造纸原料。在最高温度和液比保持不变的情况下,以保温时间、用碱量、硫化度、蒽醌用量为蒸煮参数,进行L9(3^4)硫酸盐-蒽醌法正交试验初步研究了杜仲的制浆性能,优化的蒸煮工艺条件为:用碱量18%(NaOH计),硫化度24%(NaOH计)、蒽醌用量0.05%、保温时间90min。采用HP两段漂白后,白度达74%ISO以上,且漂白浆物理性能较好。  相似文献   

4.
在对棉短绒进行基本分析的基础上进行了烧碱蒽醌法制浆工艺的探讨。通过正交实验进一步分析了高温度、用碱量、保温时间对得率、纸浆高锰酸钾值及黑液残碱的影响,得出了最佳工艺条件,并进行于验证实验。  相似文献   

5.
全棉秆蒸煮工艺条件的优化   总被引:3,自引:0,他引:3  
采用正交试验方法对全棉秆硫酸盐蒸煮方法和烧碱蒽醌蒸煮方法进行了优化.确定硫酸盐法最佳蒸煮条件是:用碱量24%,硫化度20%,最高温度1 65℃,保温时间1 20min.烧碱蒽醌法最佳蒸煮条件是:用碱量22%,蒽醌用量0.1%,最高温度1 65℃,保温时间90min.从实验结果看出全棉秆蒸煮硫酸盐法好于烧碱蒽醌法.  相似文献   

6.
在烧碱-蒽醌法制浆工艺中加入氧化铝可以提高硅在未漂麦草浆中的留着,提高纸浆纤维的灰分及二氧化硅含量,解决或减轻黑液"硅干扰"问题。本课题主要研究最佳留着浆料中的灰分及二氧化硅的蒸煮工艺。实验结果证明:将NaOH、AQ以及Al_2O_3混合均匀后再与麦草原料混合,在用碱量为14%,Al_2O_3用量为3%,蒽醌用量为0.05%,液比1:5的条件下,升温60min内到达155℃后保温30min后卸锅,该工艺可以达到最好的留硅效果。  相似文献   

7.
在烧碱-蒽醌法制浆工艺中加入氧化铝可以提高硅在未漂麦草浆中的留着,提高纸浆纤维的灰分及二氧化硅含量,解决或减轻黑液“硅干扰”问题。本课题主要研究最佳留着浆料中的灰分及二氧化硅的蒸煮工艺。实验结果证明:将NaOH、AQ以及Al2O3混合均匀后再与麦草原料混合,在用碱量为14%,Al2O3用量为3%,蒽醌用量为0.05%,液比1∶5的条件下,升温60min内到达155℃后保温30min卸锅,该工艺可以达到最好的留硅效果。  相似文献   

8.
桉木是造纸工业生产的重要原料,具有优良的制浆造纸性能,本研究首次采用粗皮桉为原料,研究其制浆性能,为造纸工业生产提供理论数据。实验的主要结果如下:家系123粗皮桉AS-AQ法蒸煮最佳工艺条件为总碱量(以Na2O计)25%,亚硫酸化度(以Na2O计)0.5,蒽醌0.08%,NP-10用量0.3%,保温时间160min,最高蒸煮温度170℃,液比1∶4.5,家系200的最佳工艺条件为总碱量(以Na2O计)23%,亚硫酸化度(以Na2O计)0.50,蒽醌0.08%,NP-10用量0.3%,保温时间150min,最高蒸煮温度170℃,液比1∶4.5。  相似文献   

9.
本文对棉籽壳烧碱-蒽醌法蒸煮脱木质素机理和棉短绒烧碱-蒽醌法蒸煮除尘工艺进行了研究。结果表明:棉籽壳烧碱-蒽醌法蒸煮时,在升温至100℃时脱除34.57%的木质素;当温度升到160℃时,木质素的脱除率达87.11%。因此,棉籽壳烧碱-蒽醌法蒸煮脱脱木质素的阶段性可分为初始脱木质素、主要脱木质素和残余脱木质素三个阶段。另外,影响棉短绒烧碱-蒽醌法蒸煮除尘的主要因素是用碱量。其次为蒸煮最高温度,影响最小的因素为保温时间。  相似文献   

10.
在麦草蒸煮之前进行热水抽提,将抽提后的麦草与未抽提的麦草在相同反应条件下进行烧碱–蒽醌法制浆,探讨热水抽提对麦草碱法制浆后浆料性能的影响。热水抽提后麦草的制浆结果表明:抽提后麦草的蒸煮脱木素率提高,卡伯值下降,但是,浆料得率均有不同程度的降低。经过热水抽提,麦草碱法制浆性能提高,可以降低用碱量,缩短蒸煮保温时间。在本实验条件下,热水抽提的较佳工艺条件为:抽提最高温度140℃,升温时间30min,保温时间60min,液比1:10;后续蒸煮的较佳工艺条件为:用碱量12%(以NaOH计),蒸煮最高温度155℃,升温时间90min,保温时间30min,液比1:5。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
17.
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.  相似文献   

18.
19.
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.  相似文献   

20.
<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  相似文献   

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