Consumption of cholesterol oxides from fast foods fried in beef fat in New Zealand

Samples of beef dripping and plant oil-based deep-frying fat were obtained from fast-food premises in Christchurch, New Zealand, as well as samples of deep-fried battered fish and potato chips. The fat in these samples was analyzed for level of oxidation by measuring acid value, peroxide value, polar compounds, thiobarbituric acid-reactive substances (TBARS), and conjugated dienes. The acid and peroxide value results were contradictory when compared with limits set in the New Zealand Food Regulations 1984, but the levels of polar compounds were generally below 25%, indicating that the fats were well maintained. The TBARS and conjugated diene levels were compared with those for oxidized corn oil used in a feeding trial and indicated a similar oxidation level, although the amount of fat consumed in the feeding trial would be 30–50% higher. These results show that well-maintained deep-frying fat has oxidation levels sufficient to cause elevation of plasma lipid oxidation levels as observed in a human feeding trial.     

Mixtures of palm kernel oil with cocoa butter and milk fat in compound coatings

Thermal behavior of binary mixtures of palm kernel oil (PKO), cocoa butter (CB), and anhydrous milk fat was used to study mixed-lipid crystallization. This study was related to the physical properties of compound coatings made with these fats. Phase behavior was studied by evaluating changes in melting behavior with composition and time, by creating isosolid diagrams, and by monitoring polymorphic behavior. For binary mixtures, multiple melting peaks and eutectic formation were observed for 30–50% addition levels of CB to PKO, but not for addition of milk fat to PKO. For compound coatings and binary mixtures, made with the same fat composition, hardness of compound coatings increased as solid fat content (SFC) at 25°C of binary mixtures increased. Also, as SFC at 25°C of the binary mixtures increased, induction time for bloom formation and time to fully bloom for compound coatings decreased. Observation of eutectic behavior for binary mixtures indicated softness in a compound coating with the same fat composition, but the converse was not necessarily true.     

Gloss reduction in low temperature curable hybrid powder coatings

This study describes the crucial role played by acrylic resin and curing agents in the gloss reduction of low temperature curable hybrid powder coatings. The incompatibility of the acrylic resin with the primary (epoxy/polyester) resins induces a two-phase morphology and initiates the formation of micro-structured surface. DSC measurements on various mixtures reveal the relative reactivity and the role of curing agents in the gloss reduction. These results indicate that the optimization of relative reactivity and compatibility is required to achieve low gloss coatings at low curing temperature. In addition, the gloss level is strongly affected by extruding conditions. These experimental results give a possibility to develop matt and semi-matt low temperature curable powder coatings.     

有机硅树脂在粉末涂料中的改性作用及应用进展

综述了近年来国内外有机硅树脂在粉末涂料中的应用研究进展。讨论了有机硅树脂与有机树脂通过共混、化学结合作为粉末涂料基材以及互为固化剂等不同改性方式的特点。有机硅组分的引入可以改善和提高粉末涂料涂膜性能 ,特别是耐候性及耐热性能。展望了有机硅改性树脂在粉末涂料中的应用和发展前景。     

抗阴极剥离的重防腐环氧粉末涂料配方研究

对影响环氧粉末涂料阴极剥离行为的因素进行了分析,从提高涂层抗碱性介质侵蚀能力与对基材附着力入手,研制出具有较高交联密度与适度柔韧性的环氧树脂与固化剂并进行了粉末涂料配方试验,试验结果表明研制的粉末涂料可满足较高温度条件下长时间阴极剥离要求。     

防锈颜料在粉末涂料中的应用

介绍了防锈颜料及其在粉末涂料中的应用情况。随着新型高效无毒防锈颜料的不断开发,防锈粉末涂料防腐蚀能力迅速提高,其将会获得积极快速的推广应用。     

Redispersible polymer powder functionalized with NMA and its adhesive properties in dry-mixed coatings

One type of redispersible polymer powder functionalized with N-hydroxymethyl acrylamide (NMA) was developed in this work. The addition of NMA proved to have great influence on the properties of the original emulsion as well as the corresponding powders. The particle size and viscosity of original emulsions both increased with the increasing of NMA amount while the colloidal stability decreased due to the generation of oligomers. However, the fluidity and adhesive performance of the resultant powders were improved obviously by adding more amounts of NMA in polymerization. Taking the above factors into consideration, we found that 3.0?wt.% of total monomers was an acceptable percentage for the NMA to be used. Poly (vinyl alcohol) (PVA) was used as protective colloids in spray drying to prevent the coalescence of emulsion particles so that the reversible dispersion of powders could be realized. The morphology of powder particles was proved to turn into ‘donut’ shape with the increasing of PVA amount, and their reconstitution ability became better. Compared with original emulsion, the reconstituted emulsion had poorer stability and dispersity due to the coalescence of polymer particles in spray drying.     

聚异氰酸酯固化剂在热固性氟粉末涂料中的应用

探讨了聚异氰酸酯固化剂交联反应机理。介绍了热固性氟粉末涂料的制备,分析了选择不同类型的聚异氰酸酯固化剂对热固性氟粉末涂膜性能的影响,从而制得了综合性能优异的热固性氟粉末涂料。     

Performance of redispersible polymer powders in wall coatings

This study applied redispersible powder into wall coatings and compared the film microstructure and properties of dry-mixed coatings and corresponding latex coatings. It could be found that the dry-mixed coatings film had loose and uniform structure, while the latex coatings film was dense and had two-layered microstructure. Through the UV–vis spectra and dynamic light scattering, we found that the different microstructures of both coatings films were resulted from the different stability of reconstituted emulsion and original polymer emulsion, and one model was set up to demonstrate this process. The performance of dry-mixed coatings was worse compared with latex coatings, which was due to the weakened stability and adhesive ability of reconstituted emulsion after spray drying.     

含硼非均相体系中纤维素阳离子化反应的优化

在含有硼化合物（BC）的异丙醇（iPA）-H₂O非均相体系中,以3-氯-2-羟丙基三甲基氯化铵（CTA）为醚化剂,对棉短绒纤维素（Cel.）进行阳离子化反应。采用正交实验确定了影响阳离子纤维素取代度（DS）的因素,并对反应进行了优化,并采用¹H-NMR对产物的结构进行了确认。结果表明,按m(Cel.)∶m(iPAⅠ)∶m(iPAⅡ)∶m(30% NaOH)∶m(50% CTA)∶m(BC)= 100∶1000∶400∶296∶696∶20的配比,室温25 ℃活化处理60 min,50 ℃恒温反应4 h,产物取代度DS达到0.54。     

我国粉末涂料市场现状及发展趋势

1 990～ 2 0 0 2年我国粉末涂料产量年均增长率为 2 4 % ,2 0 0 2年产量为 1 6万t,居世界前列。介绍了我国粉末涂料的生产现状及其在相关行业的应用 ,分析了粉末涂料制造技术与涂装技术今后的发展趋势。指出了粉末涂料行业产品结构调整方向及应重点开发的新品种     

金红石型钛白粉在水性涂料中应用性能的探讨

从钛白粉的表观指标和应用体系,阐述了钛白粉在水性涂料中的部分应用问题,以及钛白粉的表观指标和应用体系的联系。倡导选择合适的钛白粉品种来设计水性涂料配方。     

纤维素-半纤维素混合物焙烧还原低品位软锰矿的动力学

采用TG-DTG和XRD研究了纤维素、半纤维素及其混合物焙烧还原软锰矿的动力学. 结果表明,与非生物质类还原剂相比,纤维素、半纤维素及其混合物可在低于773 K焙烧还原软锰矿,纤维素和半纤维素单独焙烧还原软锰矿的动力学可采用在JMA方程基础上提出的经验动力学函数a=1-exp{-k0exp(-Ea/RT)[(T-T0)/b]n}描述,表观活化能Ea分别为38.66和30.14 kJ/mol. 混合物还原软锰矿过程的动力学可用单一组分动力学的线性加和表示,即转化率a=Sixiaie(T-T0,i),且Sixi=1, 式中e(T-T0)是单位阶跃函数,用于避免产生无效的转化率数据.     

Nanofibrillated cellulose in wood coatings: Dispersion and stabilization of ZnO as UV absorber

The effect of nanofibrillated cellulose (NFC) on the dispersion and stabilization of zinc oxide (ZnO) nanoparticles in waterborne wood coatings was examined. Different coating compositions with and without NFC at varying concentrations of unstabilized, powdery or stabilized ZnO were produced. Properties of free coating films prepared via bar coating and wood specimens coated by brush with the coating compositions were evaluated. This included the effects of NFC and ZnO on the coating appearance, film formation, distribution of ZnO in the coatings, tensile properties and UV absorbing properties of free films and the effects of artificial weathering on the coated wood specimens. We showed that NFC significantly improved the distribution of the unstabilized ZnO in the coatings and prevented sedimentation of ZnO. NFC also improved film formation and inhibited crack formation during curing and weathering for more brittle binder materials. NFC had a pronounced matting effect but did not influence the coating colour. Colour stability of coated wood specimens during weathering was affected by the ZnO content, but needs further improvement. The results show that the biopolymer NFC is suitable to stabilize ZnO in coatings for wood, which could be of interest for other applications, as well.     

马来酸酐接枝纤维素超细纤维制备高容量可再生吸附剂

在静电纺丝制备出纤维素超细纤维（CSF）的基础上,利用马来酸酐（MAH）改性制备了新型羧基化吸附剂,接枝温度为100℃,时间为3h,MAH与CSF质量比为5：1,过氧化二苯甲酰（BPO）用量为7.5%时接枝效果最佳,取代基含量可达2.304mmol/g。通过SEM观察了纤维素超细纤维改性前后的形态分布和微观结构,通过酸碱滴定定量地测定了改性纤维素超细纤维（MAH-CSF）中的取代基含量,FTIR图谱分析定性地表明马来酸酐成功地接枝在了纤维素超细纤维上。从XRD和DSC谱图中得知MAH-CSF的晶型未发生变化但结晶度有所下降,马来酸酐改性提高了纤维素超细纤维的热稳定性。研究了CSF和MAH-CSF对亚甲基蓝的吸附性能,经马来酸酐改性后纤维素超细纤维对亚甲基蓝的吸附量从210mg/g提高到了306mg/g,这表明羧基化可极大地提高其对亚甲基蓝的吸附量。在低pH下,H⁺与亚甲基蓝间的竞染作用使得吸附剂的吸附量较小;随着吸附剂的去质子化,吸附量明显迅速增大;在pH大于5.5时吸附量增加趋势减缓。MAH-CSF与MB之间的离子交换作用使其具有更优良的吸附效果,吸附过程更适合用准二级动力学模型来描述。在超声波作用下吸附剂再生5次的吸附率达89%以上,这表明吸附剂具有很好的再生性。     

用于多边角零部件防腐蚀的水性珠光浸涂漆的研制

在日益成熟的水性涂料基础上,根据现代工件多边棱角特点,要求工件具有闪光和防腐性能。在配方中引入了珠光粉,并分析珠光粉在水性树脂中定向排列,解决珠光粉在工件边角棱处流坠、流平、流挂、涂膜不均匀问题,从而得到了一种既美观又防腐的工件。本试验优点在于被浸涂工件前处理要求不严格,采用了水性体系从而大大节省成本,达到了节能、降耗、环保的目的。     

涂料工业源挥发性有机物减排和控制研究

分别介绍了我国和美国、欧盟的VOCs减排和控制的现状及相关规范和标准。表明我国在VOCs控制方面尚没有建立完善的污染排放标准体系,应借鉴欧美在VOCs防治方面的经验,并提出相关建议以顺利开展VOCs防治工作。     

Mechanical and barrier properties of cardboard and 3D packaging coated with microfibrillated cellulose

Microfibrillated cellulose (MFC) is increasingly used with cellulosic substrates and especially with paper materials. Its use with cardboard remains not reported and the study of mechanical and barrier properties of MFC‐coated cardboard has been investigated in this article. The influence of coating process as well as the effect of MFC have been highlighted by comparing different MFC‐coated cardboard samples with PE‐coated cardboard samples. MFC was coated using bar coating process. Their distribution and homogeneity onto cardboard was observed using techniques such as SEM and FE‐SEM. Tests such as oxygen and air permeability, bending stiffness, and compressive strength have been carried out. The coating process used impacts significantly cardboard properties by two opposite ways: on one hand it damages the structure cohesion of cardboard decreasing its compressive strength; on the other hand it increases its bending stiffness by increasing considerably the samples thickness. The addition of MFC counterbalances the negative effects of the coating process: bending stiffness and compressive strength are indeed improved by 30% in machine direction. On the contrary, MFC does not enhance much cardboard barrier properties, although it considerably increases their water absorption. Within a framework of packaging application, MFC will rather have consequent effects on cardboard's properties as blend or as part of the multilayer structure. Other applications have to be considered for its use as top layer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40106.     

Polyethylene green composites reinforced with cellulose fibers (coir and palm fibers): effect of fiber surface treatment and fiber content

Coir and palm fibers from agricultural waste were investigated as reinforcement for low density polyethylene (LDPE). The effect of fiber preparation with alkaline treatment and with/without bleaching on fiber physical properties was also an objective of this study. The chemical composition and FTIR (Fourier transform infrared spectroscopy) results confirmed that palm fibers had less impurity than coir fibers. This could be the reason for a greater fiber-matrix interfacial interaction of the palm fibers as compared to that of coir fibers, which was in good agreement with the estimation of surface free energy of the dispersion component. Moreover, fiber bleaching improved the single fiber pullout stress. Composites with both alkaline treated and bleached fibers, at different fiber contents (5, 10, 15, and 20 wt.%), were manufactured using a compression molding machine. Addition of both fibers in the LDPE matrix resulted in composites with a higher Young’s modulus compared to that of homopolymer. The Young’s modulus of the composites increased with the effect of either fiber content or fiber bleaching. Differential scanning calorimetry (DSC) showed that composites reinforced with both types of fibers had a single melting temperature peak, indicating the existence of only one type of crystalline species. Moreover, there were no significant differences in the melting temperatures for the fiber reinforced composites and the homo-LDPE. The heat of fusion decreased in the case of fiber reinforced composites.