木质素基复合膜的研究进展

木质素作为自然界中储量最为丰富的芳香族聚合物,可以赋予复合膜材料良好的机械强度,以及抗氧化、抗紫外等功能。本文介绍了木质素结构特点和改性方法,重点论述了木质素及其衍生物在聚合物复合膜材料中应用的研究进展,包括木质素作为填充物增强复合膜材料的机械性能,以及木质素作为改性剂提高复合膜材料的阻隔性和热稳定性等;展望了木质素及其衍生物应用于高性能复合膜材料的研究方向及应用潜力。     

木质素/PBAT复合材料的性能提升与应用研究进展

木质素作为可再生自然资源,具有多种高附加值的功能特性,将其与可生物降解高分子聚合物复合是其转化利用的重要途径之一。然而,木质素的异质性限制了其在复合材料中的开发和利用,采取针对性的策略和方法生产高附加值的木质素基可生物降解复合材料至关重要。本文主要阐述了高性能木质素/聚己二酸/对苯二甲酸丁二酯（PBAT）复合材料的不同制备策略,如添加增容剂、木质素的溶剂分级、纳米化和化学改性等,进一步总结了该复合材料在紫外屏蔽、水蒸气/氧气阻隔和抗菌等方面的潜在应用,并对木质素/PBAT复合材料所面临的挑战和未来发展方向进行总结和展望。     

表面酯化修饰纳米纤维素在聚乳酸复合膜中的应用

本文分别以纳米纤维素和酶促酯化改性后的纳米纤维素为增强材料,以聚乳酸为基质制备了聚乳酸-酯化纳米纤维素复合膜材料。通过对不同种类复合膜材料的透光性、拉伸性能、透湿率等各项性能指标的测定,对比研究了酯化改性前后纳米纤维素对聚乳酸膜、聚乳酸复合膜性能的影响;并探讨了脂肪酸链长对聚乳酸复合膜性能的影响。研究发现,纳米纤维素对聚乳酸的阻隔性能有一定的增强效果,但其不易分散于聚乳酸中,导致所制备的复合膜机械性能降低,膜表面出现明显的纳米纤维素聚团。经酯化疏水改性后所得到的纳米纤维素能分散良好于有机溶剂中,因而酯化改性对聚乳酸-酯化纳米纤维素复合膜的透明度影响甚小;同时,由于酯化纳米纤维素分散性良好,与聚乳酸具有更强的界面结合力,因此以酯化改性对酯化纳米纤维素-聚乳酸所制备的复合膜材料的机械性能、阻隔性能等较之未改性纳米纤维素-聚乳酸复合膜有了显著提高。这种新型复合膜可作为可降解性食品包装材料,在食品化工等领域有着良好的应用前景。     

Genipin交联明胶/溶菌酶缓释抗菌膜材料的微结构与性能研究

针对亲水明胶膜材料对抗菌剂缓释能力较差的问题,采用生物交联剂(genipin)调节膜材料微结构,制备出新型控释明胶/溶菌酶复合膜材料。系统研究了复合膜材料的力学性能、水汽阻隔性能、膨胀性和热性质等物理性能,并用AFM研究了膜材料的表面微结构,探讨了其结构-性能之间的关系。结果表明:genipin交联显著改善复合膜材料的力学性能,TS值从9.72 MPa逐渐增加至18.80 MPa;复合膜材料的膨胀度(swelling)随genipin浓度增加急剧下降,从1316%降至~200%;genipin交联提升复合膜材料的热稳定性。复合膜材的表面粗糙度依赖于genipin浓度,在低浓度段(0~1.0%),膜材料呈现平整表面微结构;高浓度(2.0%)时,膜表面出现不规则的突起,变得粗糙。适度的genipin交联有助于形成有序的三维网络结构,改善复合膜材料的物理性能;高浓度的genipin过度交联明胶基质,形成团聚状聚集物,及弱化明胶分子间相互作用,进而弱化膜材料的水汽阻隔能力。     

木质素结构对其纳米化的影响及木质素纳米颗粒的功能性应用

木质素纳米颗粒结构和形态多样、绿色环保且可生物降解,其功能性开发和利用受到了广泛关注。受原料及生产工艺的影响,木质素结构差异较大,相应地影响了其纳米颗粒形态、尺寸、稳定性和化学性质等。本文综述了近年来木质素纳米颗粒的制备方法及其性能和应用的研究进展,重点介绍了木质素的结构特征对木质素纳米颗粒形态与功能性的影响,探讨了木质素纳米颗粒在增强纳米复合材料、紫外屏蔽材料、生物医学材料及食品包装等方面的应用,为其在高附加值生物基材料方面的开发提供一定参考。     

高阻隔材料在生化防护领域的应用及发展趋势

探讨高阻隔材料在生化防护领域的应用现状及发展趋势。介绍了高阻隔生化防护材料的阻隔机理;介绍了橡胶基防护材料、高聚物薄膜材料、改性高分子阻隔膜和高分子复合阻隔膜的性能及优缺点;对高阻隔生化防护材料性能的评价指标进行了介绍,包括气密性、液体穿透性能、液体耐压穿透性能、力学性能和舒适性等。举例阐述了高阻隔材料在国内外优异的个体防护装备和集体防护装备中的应用。认为:高阻隔生化防护材料应拓宽化学防护谱系,拓展能够有效防护的危险化学品种类;通过引入新的材料,赋予传统阻隔膜材料智能化功能;不断优化制造工艺,运用先进的制造技术。     

慈竹木质素酚与聚羟基丁酸酯复合膜性能研究

采用相分离法制备了4种慈竹木质素酚(木质素对甲酚、木质素邻苯二酚、木质素间苯二酚、木质素邻苯三酚)。将4种木质素酚分别与聚羟基丁酸酯(PHB)共混制膜,探讨了木质素酚种类及用量对复合膜力学性能的影响,并对木质素对甲酚与PHB复合膜的吸水性和热学性能进行了分析。结果表明,现有工艺条件下木质素酚的最佳添加量应不超过10%;相同添加量下,木质素邻苯二酚和木质素间苯二酚与PHB的复合膜的力学性能好于木质素对甲酚和木质素邻苯三酚与PHB的复合膜。     

纳米粒子对多糖基复合膜微观结构的影响研究进展

多糖基复合膜具有均匀、透明和可降解等特点,成为生物可降解膜领域的热点研究内容。研究发现,纳米粒子与多糖溶液共混能形成复杂的成膜液,干燥成膜后,膜的原生微观结构改变,进而改善复合膜的力学、阻隔等性能。本文简述了淀粉膜、壳聚糖膜和魔芋葡甘聚糖膜三种多糖膜的微观结构及组分分子间的相互作用,并对纳米粒子与多糖共混成膜后,复合膜微观结构和理化性能的变化进行了重点阐述,以为多糖基复合膜微观结构设计与膜性能调控研究等提供参考。     

木质素基抗紫外线防护材料的应用研究进展

本文从木质素防晒产品和木质素抗老化复合材料两个方面,对木质素在抗紫外线防护领域的相关研究展开了综述,探讨了木质素对复合材料特性如紫外稳定性、力学性能等的影响,并对木质素在抗老化复合材料应用中存在的问题进行了剖析。此外,根据木质素抗紫外线防护机理,对其在抗老化复合材料应用中的前景进行了展望,为木质素高值化开发利用提供参考。     

工业木质素活化改性及其在复合材料中的应用进展

不同原料和制浆工艺所得的工业木质素的结构与基团差别很大,其反应活性也较原本木质素要低。因此,可以通过活化改性改善其物化性能,以提高与其他聚合物的相容性,进而制备出化学性能优良的木质素基复合材料。本文综述了工业木质素的主要活化改性方法,对改性木质素在紫外防护、抗菌和抗氧化、吸附、生物医学和农药缓释等木质素基复合材料方面的应用进展做了详细介绍。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press