核壳型氟化阳离子表面施胶剂的制备及应用

以苯乙烯、丙烯酸丁酯、甲基丙烯酸十二氟庚酯等为原料,不使用有机溶剂及乳化剂,采用自制阳离子聚合物为分散剂合成了核壳型氟化表面施胶剂(FAE).用IR、TEM、纸张物理性能检测等手段对聚合物结构、乳液粒子形态以及应用性能进行了表征.结果表明,以m(氧化淀粉):m(FAE)=85:15的施胶液进行表面施胶,当其施胶量为1.5 g/m2时,可使纸张的吸水性(cobb法)和表面强度分别达到29.9 g/m2和2.97 m/s,抗张指数和耐破指数分别达到58.8 N·m/g和2.76 kPa·m2/g.乳胶粒子呈球形,粒径分布均匀.     

丙烯酸酯聚合物表面施胶剂的合成与应用

采用种子半连续法乳液聚合工艺,以十六烷基三甲基氯化铵(CTAC)和壬酚基聚氧乙烯醚(OP-10)复配作为乳化剂,选用甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)和丙烯酸-β-异辛酯(2-EHA)为单体,经偶氮二异丁基脒盐酸盐(AIBA)引发上述单体的自由基乳液共聚反应,以制备一种阳离子型丙烯酸酯聚合物表面施胶剂。采用傅里叶红外光谱(FT-IR)和示差扫描量热分析仪(DSC)对聚合物进行表征;以马尔文粒度仪和透射电子显微镜(TEM)研究聚合反应中各种因素对乳液聚合的稳定性、聚合物乳胶粒子的粒径及其分布、乳胶粒子的形态结构的影响;通过扫描电子显微镜(SEM)、表面张力仪和Cobb值测定仪对采用该乳液表面施胶前后纸张的表面形貌、静态接触角以及抗水性进行观察和测试。研究结果表明,当AIBA用量为单体总量的1.6%、DMC用量为单体总量的5.0%以及2-EHA用量为单体总量的15.0%时,自制聚合物乳液的表面施胶效果最佳。     

含氟丙烯酸酯乳液表面施胶剂的制备与应用

以甲基丙烯酸六氟丁酯(FMA)、醋酸乙烯酯(VAc)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)为单体,采用种子乳液聚合法制备了一种能够明显提高纸张施胶效果的含氟聚丙烯酸酯乳液。分析了FMA用量对该乳液的性能影响,测定了乳胶膜的对水接触角和吸水率。试验结果表明,用含氟聚丙烯酸酯乳液与淀粉复配进行表面施胶,当其施胶量为1.5g/m2时,可使纸张表面强度增强的同时大大提高纸张的施胶度。     

无皂苯丙聚合物/AKD乳液表面施胶剂的制备与应用

以甲基丙烯酸(MAA)、苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,通过无皂乳液共聚反应制备了一种两性聚合物乳液表面施胶剂(ASAP)。以其为分散稳定剂制备了ASAP/AKD乳液表面施胶剂。以质量分数为0.15%的ASAP/AKD、质量分数为5%氧化淀粉表面施胶液,施涂量为1.2g/m2,对草木混合浆抄造纸张进行表面施胶,施胶度达113s。在ASAP/AKD乳胶质量分数为0.20%时,能显著改善纸张表面强度,耐折度、环压指数分别提高71.4%和40.7%。     

含氟丙烯酸酯乳液的制备及其用作纸张防油剂的研究

以甲基丙烯酸十二氟庚酯(FM),丙烯酸丁酯(BA)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)、N-羟甲基丙烯酰胺(NMA)为原料.制备了自乳化阳离子含氟丙烯酸酯多元共聚物乳液.将w(DMC)=10%、软硬单体比例n(BA)/n(FM)=1.1、w(NMA)=5%时所合成的乳液以质量分数5%进行表面施胶,施胶量为1.2 g/m2时,抗油渗透时间为62 min,表面强度达4.3 m/s.并通过红外光谱(FT-IR)、差示扫描量热(DSC)和透射电镜(TEM)等埘乳液性能和共聚物结构进行了表征.结果表明,共聚物玻璃化转变温度为50%左右,乳液粒子呈规则球形,乳胶粒平均粒径为96～102 nm.     

SAE聚合物表面施胶剂的制备及应用

以苯乙烯、丙烯酸丁酯、丙烯酸甲酯、丙烯酸异辛酯、甲基丙烯酸羟乙酯、甲基丙烯酸羟丙酯等为主要原料．采用半连续滴加聚合技术制备了阴离子苯乙烯丙烯酸酯共聚物乳液。单独使用该乳液作为表面施胶剂对纸张进行表面施胶，探讨了表面施胶剂用量、施胶温度、干燥温度等条件对纸张的强度和抗水性能的影响．实验结果表明：用自制表面施胶剂对纸张施胶后可使纸张获得良好的抗水性能和物理强度，当表面施胶剂用量为5％、施胶温度为50℃、施胶后干燥温度在80℃以上时，表面施胶后纸张的各项性能指标达到最佳。     

纳米SiO2/苯乙烯-丙烯酸酯树脂纸张增强剂的制备及其应用

以含双键的纳米二氧化硅粉体与丙烯酸酯类单体通过原位无皂乳液聚合合成了表面施胶增强剂。材料的力学性能和耐水性均好,其中拉伸强度最高可达5.5 N.mm-2,断裂伸长率可达到102%;耐水性最低为12.5%。FT-IR分析表明,表面含双键的纳米SiO2(RNS-D)作为反应单体参与聚合反应,实现了聚合物-无机之间的化学键合,两者复合达到分子水平。应用结果表明,杂化材料用作纸张表面施胶增强剂不仅提高了纸张强度,还使纸张的施胶度得到了提高,在杂化材料用量为1%时抗张强度提高16.1%,拉毛强度提高30.4%,施胶度可达65 s。杂化材料与淀粉施胶剂复配有联合增效作用。     

苯乙烯-马来酸酐作分散剂的丙烯酸酯聚合物表面施胶剂的制备及应用

用溶液聚合法制备了苯乙烯-马来酸酐(SMA)共聚物,经氨水水解,得到水溶性高分子分散剂。以此作为高分子分散剂与苯乙烯(St)、丙烯酸(AA)、丙烯酸丁酯(BA)和丙烯酸羟乙酯(HEA)进行无皂乳液聚合制备出丙烯酸酯聚合物表面施胶剂。应用实验表明,单独使用进行表面施胶后的纸张有良好的抗水性能,施胶后的纸张施胶度可达120s,其抗张强度、耐破度、耐折度和环压强度分别可以提高21%、12.5%、26%和12.3%。     

苯丙表面施胶剂的合成及应用

以马来酸酐、聚乙二醇1000、氯磺酸和氢氧化钠为原料制备了反应型乳化剂马来酸聚乙二醇酯硫酸钠(MP),然后以MP、苯乙烯、丙烯酸丁酯、丙烯酰胺和甲基丙烯酰氧乙基三甲基氯化铵为原料,以过硫酸铵为引发剂,制备了苯丙表面施胶剂。以FT-IR和TEM对合成的表面施胶剂进行了结构表征,FT-IR分析表明苯丙表面施胶剂具有预期的共聚物结构;TEM分析显示其乳液微粒呈球形,微粒直径约为145 nm。对比自制苯丙表面施胶剂和十二烷基苯磺酸钠(SDBS)/OP-10形成的乳胶膜的耐水性(自乳胶膜形成后15天测试2种乳胶膜的吸水率分别达到19.1%和44.2%)可知,自制苯丙表面施胶剂形成的乳胶膜具有很好的耐水性。与未施胶纸及采用市售产品和进口产品进行表面施胶的双胶纸相比,利用自制苯丙表面施胶剂和表面施胶淀粉复配对双胶纸进行表面施胶后的纸张的抗水性能和强度性能明显提高。     

麦草浆的含氟PUA中性胶湿部应用研究

用自制的阳离子含氟聚氨酯-丙烯酸酯复合乳液(PUA)作为中性施胶剂,研究了其在漂白麦草浆中的湿部应用,重点探讨了醋酸锆(ZA)、羧基丁苯胶乳(CSBL)、阳离子淀粉(CS)、硫酸铝(AS)、聚酰胺多胺环氧氯丙烷(PAE)和阳离子聚丙烯酰胺(CPAM)等6种助留剂对阳离子含氟PUA中性施胶剂施胶效果的影响。结果表明,在中性条件下,PAE和CS的助留效果最好:该施胶剂能够使纸张抗张指数提高24.08%、透气度降低18.07%;同时,还讨论了施胶顺序、pH和碳酸钙用量等湿部因素对施胶效果的影响。     

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.     

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.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.