WF/PVC木塑复合材料理化性能的研究

选用废弃木粉、聚氯乙烯塑料为原料,通过硅烷偶联剂、钛酸酯偶联剂处理木粉、马来酸酐接枝共聚PVC等方法进行改性模压制备木塑复合料,并初步研究了其理化性能。结果表明,经改性剂处理复合材料的拉伸强度、冲击强度、吸水率及厚度膨胀率等理化性能均比改性前有所提高。经硅烷偶联剂、钛酸酯偶联剂处理木粉再分别与马来酸酐接枝共聚PVC树脂进行复合所制备的复合材料的性能明显优于单一种改性的性能。同时采用FT-IR、SEM对木塑复合材料进行了分析。     

WF／PVC木塑复合材料理化性能的研究

选用废弃木粉、聚氯乙烯塑料为原料，通过硅烷偶联剂、钛酸酯偶联剂处理木粉、马来酸酐接枝共聚PVC等方法进行改性模压制备木塑复合料，并初步研究了其理化性能。结果表明，经改性剂处理复合材料的拉伸强度、冲击强度、吸水率及厚度膨胀率等理化性能均比改性前有所提高。经硅炕偶联剂、钛酸酯偶联剂处理木粉再分别与马来酸酐接枝共聚PVC树脂...     

天然橡胶/改性碱木素复合材料的制备及性能研究

对碱木素进行羟甲基化改性,并以此为原料制备天然橡胶/改性碱木素复合材料。研究了复合材料的力学性能、热稳定性、加工性能以及碱木素的微观形貌。结果表明:当甲醛用量为1.0mol/kg碱木素,改性碱木素添加量为10%,丙三醇添加量为6g/100g改性碱木素时,复合材料的力学性能最优。热重分析显示:天然橡胶和复合材料的热稳定性十分接近,复合材料的成炭量有所增加。橡胶加工性能分析(RPA)表明:碱木素经改性后,在天然橡胶中的分散性得到了改善,与天然橡胶基体的相容性得到了提高;复合材料的储能模量、损耗模量和损耗因子增加。     

秸秆纤维/聚丙烯复合材料的制备及性能研究

以秸秆纤维和聚丙烯为原料,利用双螺杆挤出机共混挤出造粒,然后热压成型制备聚丙烯木塑复合材料。研究了秸秆纤维的用量、偶联剂的种类及用量对该复合材料力学性能和热性能的影响。结果表明:经偶联剂处理后,复合材料的韧性有明显提高,其中,硅烷偶联剂含量为秸秆的10wt%时,可使复合材料的冲击强度在秸秆浓度0.1%时提高91.46%。电镜分析其断面微观结构表明偶联剂处理增加了基体与纤维的界面结合,复合材料的热重实验表明秸秆对复合材料的热稳定性基本没影响。     

不同偶联剂对空心玻璃微球/酚醛复合泡沫塑料界面性能的影响EI北大核心CSCD

以不同种类的偶联剂对空心玻璃微球表面改性,改性后的微球填充酚醛树脂制备了酚醛复合泡沫塑料。研究了空心微球改性前后的表面性能和酚醛复合泡沫塑料的弯曲强度、断裂韧性以及动态力学性能的变化。结果表明:经过偶联剂处理后的空心微球,降低了空心微球之间的团聚,增加了表面疏水性,改善了与基体间的相容性和界面性能,提高了复合材料的各项性能。不同种类偶联剂中,钛酸酯偶联剂以物理缠结的方式同酚醛基体聚合物链连接,硅氧烷偶联剂除部分与甲阶酚醛中的羟甲基有化学键合作用,大部分仍以物理缠结为主,戊二醛和硅氧烷协同改性通过形成缩醛结构将微球与基体连接起来,因此,在酚醛基复合材料中以戊二醛和硅氧烷偶联剂协同改性的效果最为明显。     

不同偶联剂对空心玻璃微球/酚醛复合泡沫塑料界面性能的影响

以不同种类的偶联剂对空心玻璃微球表面改性,改性后的微球填充酚醛树脂制备了酚醛复合泡沫塑料。研究了空心微球改性前后的表面性能和酚醛复合泡沫塑料的弯曲强度、断裂韧性以及动态力学性能的变化。结果表明:经过偶联剂处理后的空心微球,降低了空心微球之间的团聚,增加了表面疏水性,改善了与基体间的相容性和界面性能,提高了复合材料的各项性能。不同种类偶联剂中,钛酸酯偶联剂以物理缠结的方式同酚醛基体聚合物链连接,硅氧烷偶联剂除部分与甲阶酚醛中的羟甲基有化学键合作用,大部分仍以物理缠结为主,戊二醛和硅氧烷协同改性通过形成缩醛结构将微球与基体连接起来,因此,在酚醛基复合材料中以戊二醛和硅氧烷偶联剂协同改性的效果最为明显。     

利用秸秆纤维制备高吸水材料的研究

以麦秸秆为原料,通过添加丙烯酸类单体和蒙脱土,采用水溶液聚合法制备了高吸水性材料.考察了麦秸秆的预处理方式(酸处理、碱处理和醚化处理)及交联剂用量时高吸水性材料性能的影响,以红外光谱和扫描电镜表征高吸水性材料的结构.研究结果表明,采用醚化方式处理的麦秸秆制备的高吸水材料性能最好,随交联剂用量的增加,材料的吸水性呈先增大后减小的趋势.丙烯酸类单体成功发生了接枝聚合反应,高吸水材料呈现典型的三维网络结构.     

纳米TiO2的改性及其制备的TiO2/环氧树脂涂层的性能

过去,采用偶联剂等对纳米TiO2粉体改性的效果不好,影响了其制备的环氧树脂复合涂层的性能.以多羟基化合物三乙醇胺(TEA)对纳米TiO2预处理,再用硅烷偶联剂KH560或硬脂酸对其改性,并用其制备含2.0％TiO2的环氧树脂复合涂层.利用傅里叶红外变换光谱仪、激光粒度仪和紫外/可见分光光度计对改性结果进行表征,并用扫描电子显微镜(SEM)观察含2.0％改性纳米粉体的复合环氧涂层的表面形貌,通过电化学工作站、准动态高温高压釜测定其阻抗、耐高温高压性能.结果表明:通过三乙醇胺预处理后,改性纳米TiO2粉体的有效粒径有所减小,透过率有所增加;含改性纳米粉体的复合涂层阻抗性能、高温高压性能有一定的提升,经TEA预处理再有机改性的纳米TiO2制备的复合涂层性能可进一步提高.     

改性油松木粉/不饱和聚酯树脂复合材料界面性能研究

为改善油松木粉与不饱和聚酯树脂(UPR)的界面相容性,采用氢氧化钠处理、偶联剂处理、接枝改性和包覆处理方法对油松木粉进行改性,对改性木粉/UPR复合材料进行冲击和拉伸性能测试;通过观察试样冲击断口形貌,判断两相界面相容性情况。结果表明:木粉经接枝改性后增韧效果最佳,复合材料的冲击强度提高了148.3%;包覆处理后增强效果最佳,复合材料的拉伸强度提高了17.4%。同时碱处理、偶联剂处理和包覆处理能不同程度地提高复合材料的拉伸和冲击性能。接枝改性能大幅提高复合材料的冲击性能,但对拉伸性能提高不明显甚至下降。通过观察试样冲击断口,改性后油松木粉与UPR的界面相容性得到明显改善。     

碳纤维体系导电涂料的制备工艺

研制了一种以丙烯酸酯类树脂为基料的改性碳纤维体系导电涂料.用单因素方法确定改性碳纤维/树脂质量比,偶联剂的种类、用量以及添加方式、涂料的固化工艺等方面对涂料电性能的影响关系,然后用正交实验进一步优化各因素对涂膜导电性能的影响,确定了制备碳纤维体系导电涂料的最佳工艺条件为:改性碳纤维/树脂质量比为0,7,钛酸酯偶联剂TMC-102采用预处理用量为1%(wt,下同)和直接加入用量为1.5%相结合,制得的导电涂料综合性能较好;固化温度为50℃下固化20min,涂膜厚度为150μm时,其表面电阻率达到1.02Ω/sq.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.