水性聚氨酯复鞣剂的研究进展及发展趋势(续)

回顾了水性聚氨酯复鞣剂的发展历程,并简述了聚氨酯的结构及合成路线。把水性聚氨酯复鞣剂分为阴离子型、阳离子型、两性离子型和非离子型,并对相应的合成方法、改性研究进行了系统的概述。同时介绍了聚氨酯复鞣剂与皮胶原相互作用机理的研究状况,最后对水性聚氨酯复鞣剂的发展趋势进行了展望,指出在传统水性聚氨酯上引入功能性基团进行改性,开发和研制多性能复合型聚氨酯树脂复鞣剂,将是今后聚氨酯树脂复鞣剂的一个重要发展方向。     

水性聚氨酯复鞣剂的研究进展及发展趋势

回顾了水性聚氨酯复鞣剂的发展历程,并简述了聚氨酯的结构及合成路线。把水性聚氨酯复鞣剂分为阴离子型、阳离子型、两性离子型和非离子型,并对相应的合成方法、改性研究进行了系统的概述。同时介绍了聚氨酯复鞣剂与皮胶原相互作用机理的研究状况,最后对水性聚氨酯复鞣剂的发展趋势进行了展望,指出在传统水性聚氨酯上引入功能性基团进行改性,开发和研制多性能复合型聚氨酯树脂复鞣剂,将是今后聚氨酯树脂复鞣剂的一个重要发展方向。     

使用热反应型水溶性聚氨酯的仿麻整理与透明印花

最近服装行业的发展动向随着服装式样的多品种化以外,还有根据消费意愿而进行的感性整理,如超柔软、折皱、仿麻、透明、上光、拷花等及更高级的功能整理如透湿防水,抗静电吸湿,洗可穿,防缩,超拒水等大为流行。本文介绍使用热反应型水溶性聚氨酯进行仿麻整理及透明印花。 一、热反应型水溶性聚氨酯树脂 一般水溶性聚氨酯树脂在高聚物的主链中必须引进阴离子型、阳离子型及非离子型基因,使用乳化剂进行强制乳化法制造,故存在耐洗性,耐干洗性等问题。     

专利文摘

正【名称】一种基于氢键自组装构建的无铬鞣革复鞣剂的制备方法【公开号】104531916A【申请人】四川大学【摘要】本发明涉及一种(甲基)丙烯酸树脂和三嵌段非离子型双亲聚氨酯树脂基于氢键自组装构建的无铬鞣革复鞣剂及其制备方法。其特征在于所述复鞣剂的氢键组装单元是(甲基)丙烯酸树脂和三嵌段非离子型双亲聚氨酯树脂,组装单元均是应用     

高分子鞣剂的合成及其与皮胶原相互作用机理概述

对以丙烯酸类树脂鞣剂和聚氨酯鞣剂为主的高分子鞣剂的合成及其与皮胶原的相互作用机理的研究进行了综述 ,并展望了可能的发展趋势。     

阴离子型水溶性聚氨酯类树脂复鞣剂与铬鞣革的相互作用

本文采用Ｘ－射线衍射，扫描电镜，热分析等方法研究了阴离子型水溶性聚氨酯类树脂复鞣剂与铬鞣革的相互作用及鞣制条件对鞣革性能的影响。试验表明阴离子型聚氨酯树脂复鞣剂可提高铬鞣革的收缩温度及力学强度。鞣制温度以４５℃为宜。     

水溶性聚氨酯应用于涂料轧染、树脂整理一浴祛

本文简述了水溶性聚氨酯取代涂料印花粘合剂,与 CPU 树脂一起用于涂料轧染、树脂整理一浴法的可行性和优越性。文中通过一系列的性能、工艺试验,选择了合理的工艺配方。结果表明,水溶性聚氨酯应用于涂料轧染、树脂整理一浴法,可简化染色和整理的工艺流程及操作,提高涂料染色的深度、牢度和织物弹性,改善手感,因而具有广阔的发展前景。     

聚氨酯改性聚丙烯酸类填充树脂的研究

将聚醚１、甲苯二异氰酸酯（ＴＤＩ）投入反应瓶中,并在较低温度下,预聚反应１～２ｈ,然后将具有较好流动性未反应完的ＰＵ预聚体加入到聚醚２和有机酸酐半脂反应瓶中,继续进行多段共聚反应,制得改性聚氨酯（ＰＵ）溶液;然后在有机胺碱性条件下,用非离子型乳化剂进行乳化,合成出改性聚氨酯（ＰＵ）乳液。ＰＵ乳液与ＰＡ填充树脂,在一定条件下,共混合成聚氨酯改性聚丙烯酸（简称ＪＰＵ）填充树脂     

猪皮的不同脱脂方法对胶原提取率的影响

分别用4种有机溶剂、2种非离子型脱脂剂、不同用量的脂肪酶、非离子型脱脂剂AXAUT-50和异丙醇两步法、非离子型脱脂剂AXAUT-50和脂肪酶两步法,脱除新鲜猪皮中的脂肪。对脱脂后的碎皮块提取胶原,结果表明:用单一试剂脱脂时,2种非离子型脱脂剂的脱脂效果最好,脱脂率均高达67%以上,相应胶原提取率也在22%以上。两步法脱脂的效果比任何单一试剂脱脂的效果都好,尤其是AXAUT-50和异丙醇两步脱脂,其脱脂率高达90%以上,相应胶原的提取率也高达28.52%。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)谱图,显示了用不同的方法脱脂后所提取的胶原保留了天然的三股螺旋结构,黏度法测得猪皮胶原的变性温度为35.7℃。     

会议消息

1982年7月,在上海第一绸缎炼染厂举行了绢纺绸用水溶性聚氨酯后整理工艺鉴定会,出席会议的上海丝绸公司及公司所属技研所和各印染厂代表一致通过了该厂用水溶性聚氨酯整理绢纺绸新工艺的鉴定。代表们认为,新工艺基本成熟,生产效率提高,由于取消了焙烘,节约能源,而整理织物的各项指标与老工艺整理的织物大致不相上下,可以投入生产。 聚氨酯树脂一直系溶剂型的,用于织物涂层很不方便,而且在真丝织物上从未使用过。最近,上海新光化工厂合成了水溶性聚氨酯树脂,其外观为微黄色透明粘稠液体,     

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.     

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.     

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.     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.