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聚氨酯材料表面微波辅助接枝聚乙二醇的研究 总被引:1,自引:0,他引:1
采用微波辐照辅助技术在聚氨酯膜的表面接枝聚乙二醇,并与传统加热反应接枝聚乙二醇的方法进行对比。结果表明,微波辅助反应能明显加快聚氨酯表面接枝PEG的速度,其接枝效果受微波功率、反应时间以及投料比的影响。在实验条件下,微波功率为100W,反应物的质量分数为5%,反应时间为10min时,微波辅助表面接枝反应效果以及效益最好。SEM和AFM表面分析表明,与传统加热反应方法相比,微波辅助反应对膜表面的破坏程度更小,膜表面更加光滑平整。水接触角的结果也表明,微波辅助反应接枝PEG所得膜表面具有良好的亲水性能。 相似文献
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橡胶分子链在玻璃纤维表面的接枝 总被引:5,自引:0,他引:5
采用分子结构中含不饱和双键的偶联剂对玻璃纤维进行表面处理,然后在玻璃纤维表面涂覆过氧化物引发剂(BPO)及橡胶溶液、使橡胶分子链在引发剂的作用下与玻璃纤维表面的偶联剂进行接枝反应,在玻璃纤维表面接枝了一层橡胶分子链,初步分子橡胶分子链在玻纤表面的反应机遇,对几种橡胶(EPDM、顺丁橡胶、丁苯橡胶、丁腈橡胶、氨丁橡胶)在玻璃纤维表面的接枝能力及反应条件对橡胶分子链在玻璃纤维表面接枝率的影响进行了研究。 相似文献
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两步法LDPE/HSS表面光接枝的研究 总被引:1,自引:0,他引:1
采用两步表面光接枝方法研究了乙烯基苯磺酸(HSS)在低密度聚乙烯(LDPE)膜表面的接枝聚合,使LDPE膜表面有效强酸化.探讨了各反应条件对表面接枝的影响规律,利用称量法、表面水接触角测定法、红外光谱分析、扫描电镜观察等手段对表面接枝膜进行了表征。 相似文献
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《高分子材料科学与工程》2010,(8)
利用超临界CO2作为溶胀剂,进行了苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与马来酸酐(MA)的接枝反应,研究了单体浓度、反应时间等因素对接枝率的影响规律。结果表明,超临界CO2可以作为MA与SBS接枝反应的良好介质,MA的接枝率最高可达12.8%。用红外光谱(FT-IR)、扫描电镜(SEM)以及表面接触角测量仪等仪器对样品进行了表征,FT-IR证明了MA已接枝到SBS分子上,SEM观察到接枝后产物表面形成了微/纳米级的粗糙结构,接触角测试发现接枝后SBS表面水的接触角明显变小,表面由疏水变为亲水。 相似文献
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纳米二氧化硅辐射接枝制备离子交换吸附材料及其吸附性能 总被引:2,自引:0,他引:2
利用偶联剂对纳米二氧化硅进行表面化学改性,制备了乙烯基活化的纳米二氧化硅。运用γ射线引发共辐射接枝的方法在改性纳米二氧化硅上接枝甲基丙烯酸缩水甘油酯(GMA)单体,得到SiO2-g-GMA接枝共聚物,然后在共聚物表面进行氨化反应得到吸附材料。研究了单体浓度、吸收剂量等因素对GMA接枝率的影响规律,明确了反应条件与接枝率的对应关系。采用傅立叶变换红外光谱(FT-IR)表征接枝物的结构,研究了pH值、GMA接枝率、最大试样体积等影响因子对吸附的影响。 相似文献
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以乙酰丙酮(Cu(acac)2)为引发剂,研究了丙烯酰胺(AM)与炭黑(CB)的表面接枝共聚反应。讨论了引发剂、单体、炭黑和温度对接枝聚合反应的影响,利用红外光谱分析确证了炭黑表面的接枝反应,利用电镜表征了接枝炭黑的形态。表面接枝后的炭黑在水介质中的分散稳定性明显改善 相似文献
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This paper presents the test results of the swift krypton (240 MeV) and xenon ion (130 MeV) irradiation influence on the titanium surface layer properties. These ions change the titanium surface topography in different ways. The irradiation contributes to the creation of a new phase in the surface layer. Radiation damage effects on the friction coefficient, wear, and microhardness of titanium after krypton and xenon ion irradiation were studied. Krypton irradiation does not influence the microhardness of the titanium. After xenon irradiation with a fluence of 1 × 1018 ion/m2 the microhardness increases by 13%; further increases of the fluence gradually reduce the microhardness of the surface layer. Swift Kr and Xe ion irradiation does not influence the friction coefficient of the titanium surface. 相似文献
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Yaling Deng Dangsheng Xiong Silong Shao 《Materials science & engineering. C, Materials for biological applications》2013,33(3):1339-1343
In order to prolong the service life of artificial joints, a zwitterion monomer of MPDSAH ((3-(methacryloylamino)propyl)dimethyl (3-sulfopropyl)ammonium hydroxide) was grafted onto ultra-high molecular weight polyethylene (UHMWPE) powders to construct a brush-like structure by UV irradiation, and then the grafted UHMWPE powders were hot pressed as the bulk materials. The wettability of bulk materials surface with different monomer concentrations was analyzed. The tribological properties of modified UHMWPE bulk materials were investigated under distilled water and saline by sliding against stainless steel ball. The measurement of Fourier-transform infrared (FT-IR) spectroscopy indicates that MPDSAH is successfully grafted onto the surface of UHMWPE powders by UV irradiation. The contact angles of modified UHMWPE are decreased and the surface wettability is effectively improved. The friction coefficient of the modified sample is lower than that of untreated UHMWPE in aqueous lubricants during a long-term friction. With the increase of monomer concentration, the wear rate of grafted UHMWPE decreases gradually in distilled water. The grafting hydrophilic macromolecule polymer is helpful to form a lubricating film of water, which leads to the improvement of the lubricity of UHMWPE. 相似文献
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为解决核电水循环系统中鼓型旋转滤网驱动装置的耐腐蚀问题,本文研究了碳纤维和聚四氟乙烯微粉改性的聚醚醚酮复合材料在干摩擦、水润滑和油润滑条件下的摩擦磨损性能.通过机械共混、高温模压的方法,制备了不同质量分数的聚四氟乙烯(PTFE)微粉/碳纤维(CF)/二硫化钼(MoS_2)/聚醚醚酮(PEEK)复合材料.采用拉伸试验机和塑料洛氏硬度计测试其力学性能,采用摩擦磨损试验机测试了复合材料在干摩擦、水润滑和油润滑条件下的摩擦磨损性能,采用扫描电子显微镜对其摩擦表面形貌进行分析.结果表明:复合材料在水润滑和油润滑时摩擦系数及磨痕宽度均较小,但水润滑时摩擦系数波动幅度较大且磨痕宽度略高;复合材料在干摩擦条件下的磨损机制以磨粒磨损为主,伴有疲劳磨损,油润滑时摩擦面可形成连续的润滑膜而保持光滑,水润滑时水流冲刷破坏了摩擦面上固体润滑膜的稳定性;CF质量分数增加时,复合材料的洛氏硬度和压缩强度递增,压缩强度达到164 MPa,PTFE微粉质量分数增加时,复合材料的洛氏硬度和压缩强度递减;CF质量分数增加时,复合材料的干摩擦系数及磨痕宽度下降,PTFE微粉质量分数增加时,复合材料的干摩擦系数下降,达到0.17. 相似文献
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Yaling Deng Dangsheng Xiong Kun Wang 《Journal of materials science. Materials in medicine》2013,24(9):2085-2091
Osteolysis caused by wear particles from polyethylene in the artificial hip joints is a serious issue. In order to endow the low friction and wear of the bearing surface of ultra-high molecular weight polyethylene (UHMWPE) artificial joint for a longer term, hydrophilic acrylic acid (AA) was grafted on UHMWPE powders with the method of ultraviolet irradiation and then the modified powders were hot pressed. The tribological properties of modified UHMWPE sliding against CoCrMo metallic plate on reciprocating tribometer under calf serum, saline and distilled water lubrication during a long-term friction were investigated. The measurement of Fourier-transform infrared spectroscopy indicates that AA is successfully grafted on the surface of UHMWPE powders by photo-induced graft polymerization. Contact angles of UHMWPE are decreased from 83° to 35° by grafting and the surface wettability is effectively improved. The tensile strength of modified sample decreases. The friction coefficient and wear rate of UHMWPE-g-PAA under calf serum, saline and distilled water lubrication are lower than that of untreated UHMWPE. With the increase of grafting ratio, the wear rate of UHMWPE-g-PAA decreases firstly and then increases. The modified UHMWPE with grafting ratio of 3.5 % has the lowest wear rate, which is just quarter of the untreated UHMWPE. The hydrated PAA polymer brushes enclosed in the UHMWPE bulk material provide continuous lubrication during long term sliding. 相似文献
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Water droplets placed on hydrophilic surface decrease the friction coefficient in the process of sliding over the hydrophobic
surface. The droplets placed between these surfaces sustain loads of up to 170 mN and the friction coefficient for these surfaces
is equal to 1.1 · 10−3. The low value of the friction coefficient is explained by the losses of energy for the adhesion hysteresis of water on the
hydrophobic surface. In micromachines, the procedure of lubrication with water droplets efficiently decreases the friction
coefficient due to the repulsion of water from the hydrophobic surface.
Published in Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 3, pp. 109–112, May–June, 2007. 相似文献
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为了探究轮胎模具无氢类金刚石(DLC)涂层的摩擦学特性,增强轮胎模具的易脱模、防粘、自清洁性能以及提高轮胎质量与服役寿命,以轮胎模具常用的35钢为基体,利用电弧离子镀在基体试样上制备无氢DLC涂层,对涂层Raman光谱、表面粗糙度、表面微观形貌、纳米硬度、结合力和摩擦系数进行了分析,着重研究涂层摩擦前后表面微观形貌的变化以及摩擦磨损机理。结果表明:通过改变表面粗糙度可以有效降低涂层的摩擦系数,涂层摩擦系数随粗糙度减小而显著降低;在140℃高温条件下,摩擦系数最小低至0.363 4,且涂层纳米硬度可达32.45 GPa,弹性模量高达348.94 GPa。无氢DLC涂层完全满足轮胎模具减摩耐磨和自清洁性的使用要求,为制造高性能轮胎模具提供了一种可行的工艺选择。 相似文献
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The influence of ion irradiation on friction properties in vacuum of alumina ceramics was studied. The effects of irradiation fluence, ion energy, thickness of the modified layers and of the possible role of solid lubrication were analyzed. The tests performed under vacuum clearly show, that radiation damage-induced softening of the surface layer leads to significant, approximately two times, decrease of a friction coefficient. Further decrease of the friction force, down to about 1/3 of the initial value, was obtained when the implanted species revealed solid lubrication effect. The results obtained are discussed in the frames of theory of adhesive friction. 相似文献
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用模拟刹车制动的摩擦试验机,研究探讨了一种针刺毡结构C/C复合材料在不同制动压力和制动速度下的摩擦磨损性能,并用扫描电子显微镜对摩擦表面进行了观察和分析。摩擦磨损机理由磨屑经挤压、剪切堆积在表面形成的磨屑层所决定。在5m/s制动速度或静态条件下,表面温度低(<150~200℃)吸附水气未脱附,其润滑作用导致了较低的摩擦系数值;当制动速度达到10m/s,摩擦使表面温度升高,达到了吸附水气脱附温度,引起摩擦系数急剧升高,达到了最大;此后,随制动速度及表面温度的继续升高,磨屑层间剪切强度降低,导致摩擦系数随之下降。在较高制动速度下,该种材料仍能保持较高的摩擦系数,显示出优良的高温高能摩擦性能。 相似文献