一种高强度低气味低VOC聚丙烯复合材料的研究

在用POE等增韧剂、滑石粉对PP进行改性的基础上,探讨聚丙烯基料、滑石粉、增韧剂、偶联剂对聚丙烯复合材料的强度、气味、VOC(Volatile Orgnic Compounds)等的影响,以得到一种高强度、低气味、低VOC的PP合金。结果表明:使用PP EA5074S/WF-D6.5/POE 8200/KH550能得到高强度、低气味、低VOC的聚丙烯复合材料。     

复合尼龙粉末改性及激光烧结成形工艺试验研究

针对目前还不能用传统尼龙粉末材料直接烧结功能件的现状,采用溶剂沉析法合成低熔点聚酰胺粉末作为复合尼龙粉末基材,对基料添加各种无机填料进行物理共混改性。采用正交设计方法和SEM分析方法,以烧结密度和成形件综合力学性能为指标对复合尼龙粉进行烧结工艺优化试验。结果表明,通过物理共混改性能够制备出适合于选择性激光烧结用的高性能复合尼龙粉末,同时,能够大大减小复合尼龙的收缩和翘曲变形。     

纳米SiO_2/GF/PA6复合材料力学性能和摩擦学性能研究

采用注塑成型法制备纳米SiO2和玻璃纤维混杂填充PA6尼龙复合材料,对PA6复合材料的力学性能和摩擦学性能进行实验研究,采用扫描电子显微镜观察分析磨损表面形貌及磨损机制。结果表明:纳米SiO2和玻璃纤维混杂填料能使PA6复合材料的拉伸强度和表面硬度增大,可以显著改善尼龙复合材料的摩擦学性能,以5%SiO2-20%GF材料的耐磨减摩性最好;纯PA6的磨损以黏着和犁削为主;当载荷较低时,复合材料的磨损机制主要表现为不同程度的磨粒磨损,但当载荷较高时,复合材料的磨损机制主要表现为不同程度的疲劳磨损。     

纳米Si_3N_4和玻璃纤维混杂增强PA6复合材料的力学性能和摩擦学性能研究

采用注塑成型法制备纳米Si3N4和玻璃纤维混杂填充PA6尼龙复合材料,对PA6复合材料的力学性能和摩擦学性能进行了实验研究.采用扫描电子显微镜观察分析磨损表面形貌及磨损机制.结果表明:纳米Si3N4和玻璃纤维混杂填料能使PA6复合材料的拉伸强度和表面硬度增大.纳米Si3N4和玻璃纤维混杂可以显著改善尼龙复合材料的摩擦学性能,以3% Si3N4的耐磨减摩性最好.     

汽车用低VOC、低气味聚丙烯复合材料的研究

通过VOC含量、气味和综合力学性能的表征,研究低VOC、低气味聚丙烯复合材料的3种制备方法。结果表明:添加无机吸附剂和水母粒均可在一定程度上改善复合材料的VOC含量和气味性,但改善效果不明显,且无机吸附剂的加入会导致复合材料的冲击性能下降;雾化工艺显著降低了复合材料的VOC含量,材料的气味性也得到明显改善,且经过长期储存后,复合材料的VOC含量和气味性并未发生明显改变,且雾化工艺并不影响复合材料的综合力学性能。     

聚酰胺摩擦学研究进展

聚酰胺(PA)在摩擦材料领域显示出广阔的应用前景,为了进一步改善其摩擦磨损性能,可用固体润滑剂、颗粒填充、纤维增强、混杂增强等对其进行改性。综述聚酰胺的各种摩擦学改性方法及聚酰胺基复合材料的摩擦磨损形式与机制,指出聚酰胺摩擦学改性的发展方向,包括通过建立适当模型进行摩擦行为的模拟及预测,分析复合材料摩擦磨损机制及工况条件的影响;研究填料或增强纤维与PA基体的界面相容性、稳定性,考察其对摩擦磨损性能的影响;结合使用工况条件,遵循摩擦磨损机制,考察不同填料、增强体之间的协同作用,选用不同类型的增强减磨材料组元和功能组元,采用混杂增强改性,制备高性能的功能PA复合材料。     

一种耐刮擦、低气味、低VOC聚乙烯复合材料的研究

探讨吸附母粒中的PP载体、耐刮擦剂种类、加工条件对聚乙烯复合材料的耐刮擦、气味、VOC的影响,以得到一种耐刮擦低气味低VOC聚乙烯复合材料。结果表明:当真空度为0.08 MPa下,采用PE 5502S、吸附母粒(以PP Daploy WB130HMS为载体)、耐刮擦剂MB50-001、抗氧剂Irganox1010、润滑剂硬脂酸钙的体系可得到耐刮擦、低气味、低VOC聚乙烯复合材料。     

低线性膨胀系数汽车塑料尾门专用料的研制

采用聚丙烯(PP)为基体树脂,热塑性弹性体POE为增韧剂,多羟基化合物(HT-17)为表面极性剂,滑石粉(Talc)作为增强填料,制备出低线性膨胀系数汽车塑料尾门专用料。研究了PP种类、POE种类、Talc粒径以及HT-17的用量对复合材料力学性能、线性膨胀系数以及粘结性能的影响。结果表明:以BX3800为基体树脂,Solumer 8613L为增韧剂,AHCP250为增强填料,HT-17用量达到3%时,制备出复合材料完全满足汽车塑料尾门专用料的要求。     

ATR-FTIR在尼龙共混物组份分析中的应用

尼龙66(PA66)与尼龙6(PA6)结构相似、性能更优,而尼龙6熔点低、价格廉,个别厂家在追求低成本时将尼龙6掺混在尼龙66中使用难以分辨。利用红外光谱衰减全反射法分析了不同PA66/6共混物的红外光谱图差别。根据PA66/6不同共混物的红外光谱图在930~935cm-1峰位的位移变化,拟合出了半定量分析公式。对未知尼龙样品进行了红外光谱分析,确定了未知样品的组份。     

添加不同固体润滑剂橡胶复合材料的力学及摩擦磨损性能

制备了添加不同固体润滑剂(鳞片石墨、超高分子量聚四氟乙烯、尼龙6、硅脂、白色减摩剂)的纤维增强丁腈橡胶/丁苯橡胶/复合材料,研究了橡胶复合材料的硫化性能、力学性能和摩擦磨损性能。结果表明：添加超高分子量聚四氟乙烯润滑剂的橡胶复合材料的综合硫化性能最佳;润滑剂为鳞片石墨时,复合材料邵氏硬度,拉伸强度最大;润滑剂为超高分子量聚四氟乙烯时,复合材料的动摩擦因数、动摩擦因数稳定度波动幅度、磨损率、干/湿环境下动摩擦因数差值最低,分别为0.27～0.29、2%、1.4×10^-7 g·J^-1、0.01,耐磨性能和干湿环境交替稳定性最佳。     

PTFE对纤维增强尼龙66材料摩擦学性能的影响

考察了玻璃纤维（GF）增强尼龙66复合材料的摩擦磨损性能,以及PTFE对复合材料摩擦学性能的影响,利用扫描电镜分析了磨损形貌。结果表明：15％GF增强尼龙复合材料的摩擦学性能改善不明显,而且磨损量高于纯尼龙;加入PTFE在摩擦过程中形成了转移膜,降低了玻璃纤维增强尼龙复合材料的摩擦磨损,改善了其摩擦学性能。     

环氧基氟化石墨耐磨涂料的研究

以环氧树脂为黏接剂,采用酰胺类固化剂,并以氟化石墨为润滑剂,SiC为耐磨填料,制备一种常温固化的耐磨涂料。用红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)分析氟化石墨的结构和性质,用光学显微镜(OM)观测润滑剂和填料在涂料中的分散情况,探索涂料中氟化石墨和SiC的含量与涂层力学性能、摩擦性能和热性能的关系。结果表明:氟化石墨层间距为0.71 nm,晶型结构不规则,表面能较低,其润滑性能优于石墨;通过一定的工艺SiC和氟化石墨均匀地分散在涂料中;含SiC和氟化石墨的涂膜具有较好的力学性能;当SiC和氟化石墨质量分数为20%和5%时,涂层耐磨性能较好;SiC和氟化石墨使涂膜的耐热性有所改善。     

玻璃微珠填充改性含油铸型尼龙的摩擦学和热性能

以玻璃微珠为填料制备了玻璃微珠填充改性含油铸型尼龙复合材料,研究了复合材料的摩擦争性能和热性能。结果表明：加入玻璃微珠的复合材料的摩擦因数降低,耐磨性提高,其磨损行为主要是粘着磨损和磨粒磨损;该复合材料的热变形温度有所降低,但线膨胀系数减小。     

Influence of Cage Clearance on Bearing Lubrication©

The effect of the cage clearance on the lubricant supply and elastohydrodynamic (EHL) film thickness has been studied in a ball-on-disc device. A single pocket from a standard nylon cage was mounted around the ball. The cage was instrumented so that the clearance between the cage and ball could be altered. Film thickness measurements were made with and without the cage present and for different clearances. Two lubricants were tested: a lithium hydroxystearate grease and its base oil. Film thickness was measured with increasing speed to determine the onset of lubricant starvation. Without a cage present the grease lubricated contact starved at a very low speed, typically 0.02 m/s and the film thickness dropped to a fraction of the fully flooded value. Starvation did not occur within the speed range for the base oil.

The presence of the cage significantly changed the starvation response. For the base oil reducing the clearance induced starvation by locally removing the lubricant from the track. The grease gave a very different result as reducing cage clearance increased the starvation speed thus ensuring fully flooded behavior over a much greater speed range. The improvement in grease performance with the cage present is attributed to two effects. First, the cage with reduced clearance helps to redistribute the grease into the track. Second, the close conformity between cage and ball promotes shear degradation of the grease structure generating low-viscosity material, which improves replenishment.     

The effect of a solid additive on rolling fatigue life

Behaviour of a series of lubricant oils and the effect of a non stoichiometric inorganic compound, as solid extreme pressure additive, on rolling fatigue life are studied using the rolling four-ball accelerated service simulation test proposed by Barwell and Scott. The results show, in all tested cases, the remarkable efficacy of this type of additive. The Total Acidity Number (tan) was found to increase with performance time for the case of the base lubricant, while for the oils with additives, it remained at its constant low value. This led to a proposal of a possible mechanism of the additive performance in the rolling process.     

Influence of Polyfluo-Wax on the Friction and Wear Behavior of Polyimide/Epoxy Resin–Molybdenum Disulfide Bonded Solid Lubricant Coating

Polyimide/Epoxy resin–molybdenum disulfide bonded solid lubricant coatings (denoted as PI/EP-MoS₂) were prepared. The influence of polyfluo-wax (denoted as PFW) on the microhardness and friction and wear behavior of as-prepared PI/EP-MoS₂ lubricant coating was measured using a microhardness tester and a reciprocating ball-on-disc tribometer, respectively. The worn surfaces of the lubricant coatings were observed with a scanning electron microscope, and their wear rate was determined with a Micro XAM surface mapping microscope. Moreover, the transfer films formed on the counterpart steel ball surfaces were analyzed by X-ray photoelectron spectroscopy. Results indicate that the incorporation of a proper content of PFW filler is effective at improving the antifriction performance of the PI/EP-MoS₂ lubricant coating while maintaining better wear resistance. Moreover, the friction coefficient of the lubricant coating decreases with increasing content of PFW from 2 to 10%, and the one with a filler content over 6% PFW has a steady friction coefficient of 0.07. The improvement in the antifriction performance of the lubricant coating with the incorporation of the PFW filler is attributed to the excellent lubricity of homogeneously distributed PFW.     

前混合磨料水射流系统流化器密封套筒的选材

为了保证流化器高压切换阀的正常工作,需要加工与其相配套的密封套筒,以起到保证系统压力恒定不变,在高压下平稳切换磨料罐的作用。为选择合适的密封套筒材料,确保流化器切换阀的密封性和耐磨性,分别在干摩擦、水润滑和油润滑条件下对含不同质量分数短玻璃纤维的复合尼龙材料进行了摩擦学试验。结果表明,在油润滑条件下,含玻璃纤维33%左右的尼龙复合材料具有最佳的抗磨性和较小的摩擦阻力。并根据制备的复合材料,成功研制出符合系统要求的密封套筒。     

Basics: Current base oil quality and technological options for its improvement— an Overview

Recent technological developments have revolutionised the lubricant industry by spurring a widespread quality improvement in both base oils and additives, giving superior finished lubricants. The upgrading of base oils is being brought about by more demanding requirements from original equipment manufacturers (OEMs), by government regulations, and through consumer awareness, environmental concerns, decreasing supply of high‐quality lubricant‐bearing crudes, and expanding markets worldwide. Present‐day lubricant demand is for maximum oxidation stability, superior low‐temperature performance, low volatility, and improved additive response, which are difficult to achieve through conventional processing. Conventional solvent lubricant refining produces base oils with a viscosity index (VI) of 100 with a fair amount of sulphur and aromatics, i.e., Group I base oils only. The current requirements of high‐performance base oils can conveniently be met through the hydroprocessing route. Depending upon the severity level, hydroprocessing is able to produce base oils of VI 95–110, in addition to low sulphur and high saturates content (Group II and Group III) by transforming the undesirable molecules into more useful structures. In countries such as India, a hybrid approach offers a technical solution to meet current demands for lubricant quality. This approach can be implemented in existing lubricant refineries without entailing major changes in refinery configuration, besides being cost‐effective. This paper describes the current requirements of modern lubricants in relation to API Groups and trends in these, and describes a sequence of technologies involving solvent refining, a cost‐effective hybrid scheme, and more recent hydroprocessing that allows a cost‐effective upgrading of Group I refining process. A case study is given that discusses the adoption of the hybrid scheme in Indian refineries.