赛隆结合刚玉制品的制备与应用

本实验对Sialon结合刚玉的制备工艺及性能进行了研究。通过采用烧结助剂,使Sialon结合刚玉材料可在1500~1550℃的温度下氮化烧结,烧结体的密度可达3.18g/cm3,耐压强度大于135MPa,常温抗折强度达到23MPa,1600℃的热膨胀系数为6×10-6/K。SEM结果显示,刚玉颗粒与基质中的β-Sialon之间结合牢固。     

粘土碳热还原氮化二步法制备β-Sialon结合刚玉复相材料

以天然粘土为原料 ,采用碳热还原氮化法合成了β Sialon粉体 ,再将它与刚玉复合 ,常压下烧结制备了β Sialon结合刚玉复相材料 ;研究了合成β Sialon粉体的反应过程和最佳工艺参数 ,在反应温度为 1 5 0 0℃ ,保温 6h ,碳的质量分数为2 0 % ,氮气流量为 1 .5L·min- 1 的工艺条件下 ,产物中的β Sialon可达 90 % (质量分数 )以上。测定了添加不同烧结助剂的 β Sialon结合刚玉复相材料的力学性能 ,并用SEM观察了其断口形貌 ,发现添加稀土氧化物La2 O3和Y2 O3的样品烧结相当致密 ,抗折强度分别为 1 72MPa和 2 0 1MPa。     

赛隆结合刚玉制品的制备实验分析

本实验对赛隆(Sialon)结合刚玉的制备工艺及性能进行了研究。通过采用烧结助剂,使赛隆(Sialon)结合刚玉材料可在1450℃的温度下氮化烧结,烧结体的密度可达3.18g/cm3,耐压强度大于200Mpa,常温至1600℃的热膨胀系数为6×101-6/K..XRD分析表明:制品的主要晶相为刚玉和β-Sialon,另外还有少量的O-Sialon和β-Si3N4.SEM结果显示,刚玉颗粒与基质中的β-Sialon之间结合牢固。     

β-Sialon-Al2 O3-SiC系复相材料的研制和性能

研究了在 15 0 0℃的流动氮气中 ,用Al粉、Si粉、Al2 O3粉、刚玉和SiC的颗粒及细粉直接制备 β Sialon -Al2 O3-SiC系复相材料的氮化烧结技术。XRD和SEM分析表明 ,结合相 β Sialon的显微形貌随刚玉量的增加由纤维状向棱柱状转变 ,发育良好。复相材料的高温抗折强度高于常温抗折强度。抗热震试验结果显示 :添加适量的刚玉对β Sialon -SiC复相材料和添加适量的SiC对β Sialon -刚玉 复相材料都具有良好的增韧效果 ,这是β Sialon的纤维增强及柱状晶体原位自补强增韧和复合弥散相增韧综合作用的结果。抗碱和抗高炉渣试验均显示了该复相材料优良的抗碱和抗铁渣侵蚀能力。     

复相Sialon的合成及烧结行为

本文论述了复相β＇－Sialon材料的合成，及以复相β＇－Sialon结合Al2O3基材料的常压烧结行为。探讨了不同气氛、不同温度对烧结性能的影响。发现在弱还原气氛下，在1650℃时常压烧结的最大相对密度达到93％。认为材料的烧结过程是液相烧结，X相及加入的Y2O3是形成液相的主要因素．     

β-Sialon结合刚玉材料性能的研究

通过对不同刚玉 -Si粉组成的试样在不同温度下氮化结果的分析 ,研究了烧结温度及组成对 β Sialon结合刚玉材料强度、热震稳定性及抗氧化性的影响 ,指出提高烧结温度可以显著提高高温强度 ,适中的Si粉含量 ( 6%～ 9% )才能兼顾到好的热震稳定性、抗氧化性和强度     

纳米Al2O3和SiO2对刚玉质耐火材料烧结与力学性能的影响

在普通的刚玉质耐火材料中分别加入少量纳米Al2 O3和SiO2 ,研究了这两种纳米材料对经不同温度烧成后刚玉质耐火材料烧结与力学性能的影响。结果发现 :这两种纳米材料均能使刚玉制品的烧成温度降低 1 0 0～ 2 0 0℃ ,并在相同烧成条件下能使试样的常温抗折强度和耐压强度提高1～ 2倍。     

锆刚玉莫来石(AZS)推板的研制

针对目前一些磁性材料厂推板窑的作业条件，研制了一种ZrO2含量3．4％，Al2O3含量85％左右的锆刚玉莫来石堆板。配料采用粗：中：细=5：1：4颗粒级配。混练好的泥料经摩擦压砖机压制成340mm×340mm×30mm的推板，干燥后经1550℃保温8h烧成。烧成推板的指标：体积密度3．08g·cm-3，显气孔率14．7％，常温抗折强度17．9MPa，1350℃的抗折强度10．7MPa，抗热震性（1100℃-水冷）＞周次，0．2MPa荷重软化开始温度1650℃。锆刚玉莫来石(AZS)推板的研制@王立召$山东淄博裕民耐火材料有限公司!淄博,255086@沈继耀$天津大学材料科学与工程系…     

双相Sialon材料的研究

研究了工艺条件、化学组成、显微结构与材料性能的关系，制备了双相Sialon材料。该材料室温抗折强度、断裂韧性分别达到624MPa、4MPa·m1／2，硬度达到Hv2000左右。其最佳烧结温度为1550℃，1．5h。添加剂Y2O3、Al2O3和AlN的最佳含量分别为10％、5％、5％。     

国外新技术

Sialon用于破粉碎机新近开发的一种Sialon陶瓷材料正广泛用于破粉碎机，如球磨机以及颚式破碎机。据称，这种Sialon材料有（或优于）天然玛瑙一样的特性。该Sialon材料用于破粉碎机具有磨损率低、耐化学侵蚀和无金属夹杂物污染等特性。而且价格与具有一定的竞争力。这种Sialon材料通过烧结法制取，所用烧结助剂为Y，其分子式可表示为Si6-zAlzOzN8-zo烧结过程中的结合相为硅酸铝质玻璃相。商品名称为SYALON101的这种Sialon材料的密度为3．24g·cm’，硬度为gi．2RA，耐压强度高达3500MPa，抗折强度950MPa，断裂韧性（K。）约为7．7…     

Nanomechanical mapping of glass fiber reinforced polymer composites using atomic force acoustic microscopy

In this work, a dual‐frequency resonance tracking (DFRT) method was applied on atomic force acoustic microscopy (AFAM) and high‐resolution, quantitative nanomechanical mapping of a glass fiber–reinforced polymer composites (GFRP) was realized. Results show that even using the single‐frequency AFAM, the fiber, and epoxy can give very good contrast in amplitude images. The modulus mapping result on GFRP by DFRT AFAM was compared with that by dynamic nanoindentation, and it is found that DFRT AFAM can map the elastic modulus with high spatial resolution and more reliable results. The interface of GFRP was especially investigated using a 2 μm × 2 μm scanning area. Finite element analysis was implemented to investigate the effect of tip radius and the applied pressing force on the interface measurement using a sharp “interface”. By setting a linear‐modulus‐varied interface with finite width in finite element analysis (FEA), similar comparison between FEA and AFAM experimental results was also implemented. The average interface width is determined to be 476 nm based on the high‐resolution modulus image, indicating that AFAM is a powerful method for nanoscale interface characterization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39800.     

A novel Bayesian inference soft sensor for real‐time statistic learning modeling for industrial polypropylene melt index prediction

A novel real‐time soft sensor based on a sparse Bayesian probabilistic inference framework is proposed for the prediction of melt index in industrial polypropylene process. The Bayesian framework consists of a relevance vector machine for predicting melt index and a particle filtering algorithm for soft sensor optimization. An online correcting strategy is also developed for improving the performance of real‐time melt index prediction. The method takes advantages of the probabilistic inference and using prior statistical knowledge of polymerization process. Developed soft sensors are validated with ten public databases from UCI machine learning repository and real data from industrial polypropylene process. Experimental results indicate the effectiveness of proposed method and show the improvement in both prediction precision and generalization capability compared with the reported models in literatures. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45384.     

对机械设备设计研发过程的讨论

本文对机械设备设计研发过程的基本步骤、工作方法及需要引起注意的问题进行了较详细的论述,并对机械设备设计研发工作的开展提出了一些建议.     

Generalizing solubility parameter theory to apply to one‐ and two‐dimensional solutes and to incorporate dipolar interactions

Hildebrand and Hansen solubility parameters are commonly used to identify suitable solvents for the dispersion or dissolution of a range of solutes, from small molecules to graphene. This practice is based on a number of equations, which predict the enthalpy of mixing to be minimized when the solubility parameters of solvent and solute match. However, such equations have only been rigorously derived for mixtures of small molecules, which interact only via dispersive forces. Herein, we derive a general expression for the enthalpy of mixing in terms of the dimensionality of the solute, where small molecules are considered zero‐dimensional, materials such as polymers or nanotubes are one‐dimensional (1D) and platelets such as graphene are two‐dimensional (2D). We explicitly include contributions due to dispersive, dipole–dipole, and dipole‐induced dipole interactions. We find equations very similar to those of Hildebrand and Hansen so long as the solubility parameters of the solute are defined in a manner which reflects their dimensionality. In addition, the equations for 1D and 2D systems are equivalent to known expressions for the enthalpy of mixing of rods and platelets, respectively, as a function of surface energy. This agreement between our expressions and those commonly used shows that the concept of solubility parameters can be rigorously applied to extended solutes such as polymers, nanotubes, and graphene. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

涂料研究开发新进展及关键科学与技术问题

阐述了近年来国内外涂料的研究开发现状,包括:利用新的树脂合成方法获得新的成膜物;直接引入无机纳米粒子以改善涂层性能;表面微纳结构构建以获得功能涂层等;提出了未来涂料技术的发展趋势,包括:环保化和健康化;通用涂层的高性能化;多功能化和智能化等;和需要突破的关键科学与技术问题。当企业发展到一定阶段和规模后,要加强科研开发的投入,加强产学研合作,加强基础研究,要敢于开发国外没有的技术和产品,敢于领先国外技术,才能真正成为涂料强国。     

TiO2‐Oligoaldaramide nanocomposites as efficient core‐shell systems for wood preservation

Homogeneous core‐shell systems were obtained with a growth, in controlled steps, of several oligoamides on TiO₂ nanoparticles. Derivatives of natural compounds, such as l ‐tartaric acid and α,α′‐trehalose, were used as diesters in the polycondensation reactions with ethylenediamine. TiO₂ anatase was chosen because of its high photo‐activity and its antimicrobial activity. The TiO₂ nanoparticles had been previously activated then functionalized using two different coupling agents, and finally, the TiO₂‐oligoamide nanocomposites were synthesized using two synthetic pathways. The final products were characterized by ¹H NMR, ¹³C NMR, FT‐IR, and transmission electron microscope. These nanocomposites can show improved properties in comparison with the single components (TiO₂ nanoparticles or oligoamides), which are useful in many fields, such as antimicrobial coatings for surfaces in cultural heritage conservation. A nanocomposite (TiO₂‐polyethylenetartaramide) was used for applicative studies, and it has shown a good efficacy against fungal attack by Trametes versicolor on wood specimens (Fagus sylvatica). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42047.     

Preparation and testing of Nafion/titanium dioxide nanocomposite membrane electrode assembly by ultrasonic coating technique

Membrane electrode assemblies with Nafion/nanosize titanium dioxide (TiO₂) composite membranes were manufactured with a novel ultrasonic‐spray technique (UST) and tested in proton exchange membrane fuel cell (PEMFC). The structures of the membranes were investigated by scanning electron microscopy (SEM), X‐ray diffraction (XRD), and thermogravimetric analysis. The composite membranes gained good thermal resistance with insertion of TiO₂. The SEM and XRD techniques have proved the uniform and homogeneous distribution of TiO₂ and the consequent enhancement of crystalline character of these membranes. The existence of nanometer size TiO₂ has improved the thermal resistance, water uptake, and proton conductivity of composite membranes. Gas diffusion electrodes were fabricated by UST. Catalyst loading was 0.4 (mg Pt) cm^?2 for both anode and cathode sides. The membranes were tested in a single cell with a 5 cm² active area operating at the temperature range of 70°C to 110°C and in humidified under 50% relative humidity (RH) conditions. Single PEMFC tests performed at different operating temperatures indicated that Nafion/TiO₂ composite membrane is more stable and also performed better than Nafion membranes. The results show that Nafion/TiO₂ is a promising membrane material for possible use in PEMFC at higher temperature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40541.     

Poly(butylene succinate)/layered double hydroxide bionanocomposites: Relationships between chemical structure of LDH anion,delamination strategy,and final properties

A series of poly(butylene succinate) (PBS) containing organo‐modified layered double hydroxide (LDH) are prepared by melt compounding and by in situ polymerization of succinic ester and 1,4‐butanediol. Various LDHs intercalated with renewable organic anions are used. More specifically, lauryl sulfate, stearate, succinate, adipate, sebacate, citrate, and ricinoleate ions are used as LDHs organo‐modifiers. The thermal, rheological, and dynamic mechanical properties of the samples are investigated. The results reveal a general mechanical reinforcement imparted by the clays. Significant changes are observed for the in situ polymerized nanocomposites, especially for LDH stearate which improves the properties of PBS nanostructure, whereas very few differences are observed for the other samples. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1931–1940, 2013     

Synthesis and properties of cross‐linked polymers from epoxidized rubber seed oil and triethylenetetramine

A series of epoxidized oils were prepared from rubber seed, soybean, jatropha, palm, and coconut oils. The epoxy content varied from 0.03 to 7.4 wt %, in accordance with the degree of unsaturation of the oils (lowest for coconut, highest for rubber seed oil). Bulk polymerization/curing of the epoxidized oils with triethylenetetramine (in the absence of a catalyst) was carried out in a batch setup (1 : 1 molar ratio of epoxide to primary amine groups, 100°C, 100 rpm, 30 min) followed by casting of the mixture in a steel mold (180°C, 200 bar, 21 h) and this resulted in cross‐linked resins. The effect of relevant pressing conditions such as time, temperature, pressure, and molar ratio of the epoxide and primary amine groups was investigated and modeled using multivariable nonlinear regression. Good agreement between experimental data and model were obtained. The rubber seed oil‐derived polymer has a T_g of 11.1°C, a tensile strength of 1.72 MPa, and strain at break of 182%. These values are slightly higher than for commercial epoxidized soybean oil (T_g of 6.9°C, tensile strength of 1.11 MPa, and strain at break of 145.7%). However, the comparison highlights the potential for these novel resins to be used at industrial/commercial level. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42591.     

Lipid Composition,Natural Antioxidants and Physicochemical Characteristics in Liver Oil from Rajiforms from the Gulf of Mexico

Lipid composition by class, fatty acids, natural antioxidants (carotenes, tocopherols) and physicochemical characteristics of liver oil from three commercial rays, Rhinoptera bonasus (Chucha), Aetobatus narinari (Pinta) and Dasyatis americana (Bala) from the Gulf of Mexico were analyzed. Liver oil yield for R. bonasus, A. narinari and D. americana were of 43.04, 41.2 and 38.2% (wet weight), respectively. Triacylglycerols were the most abundant lipid by class in R. bonasus (68.9%), A. narinari (85.9%) and D. americana (81.6%), while sterols esters, sterols, di- and monoacylglycerides, polar lipids and wax esters were found in minor proportions. Species showed similar carotenes concentration, 8.7, 12.8 and 8.0 μg/g for R. bonasus, A. narinari and D. americana, respectively. α-tocopherol concentration was higher (p < 0.05) for A. narinari (46.7 mg/100 g) than for R. bonasus (21.0 mg/100 g) and D. americana (13.7 mg/100 g). Omega-3 polyunsaturated fatty acids in R. bonasus were high with docosahexaenoic acid (12.1%) in a higher proportion than eicosapentaenoic acid (7%).