碳纳米管的化学修饰以及作为润滑油添加剂的摩擦学性能研究

采用硫酸和硝酸混合酸对催化裂解法(CVD法)制备的多壁碳纳米管(MWNNTs)进行纯化,然后运用硬脂酸对碳纳米管进行表面修饰,并研究了硬脂酸修饰后的碳纳米管的表面状况以及作为润滑油添加剂的摩擦学行为．实验结果表明,在硫酸催化剂作用下,通过酯化反应碳纳米管能够被硬脂酸包覆,并且硬脂酸修饰的碳纳米管作为润滑油添加剂能够显著提高基础油的减摩抗磨性能,当添加量为0．15％左右时,润滑油的减摩抗磨性能最佳,与基础油相比可以使摩擦系数下降10％左右,磨损量下降30％～60％．     

45#钢等离子渗氮在不同润滑剂下的摩擦磨损性能研究

利用脉冲直流等离子对45#钢进行等离子渗氮,用X射线散射分析等离子渗氮表面成分,并测量了渗氮前后表面硬度,利用SRV摩擦磨损试验机考察45#钢等离子渗氮前后在含磷酸三甲酚酯、硫化异丁烯和离子液3种润滑剂润滑下的摩擦磨损性能,通过扫描电子显微镜和X射线光电子能谱仪对3种润滑剂的抗磨减摩机理进行分析.结果表明:等离子渗氮后可以提高45#钢表面的硬度;在磷酸三甲酚酯、硫化异丁烯和离子液润滑下,其抗磨性能大幅度提高,等离子渗氮层具有良好的抗磨性能,其中1-丙基-3-辛基咪唑六氟磷酸盐离子液具有优良的抗磨减摩性能.这是由于润滑油中活性元素与渗氮层协同作用的结果.     

铝基矿物在钙基固硫过程中的固相反应机理分析

在高温电阻炉中对高硫煤掺入钙铝基添加剂后进行燃烧试验,分析了不同条件下煤中加入添加剂后固硫效率、固硫灰渣的矿物组成及微观形貌的变化特性;综合采用TG-FTIR-XRD研究了化学纯矿物CaO-A12O3-CaSO4体系中硫酸钙的高温热分解过程及产物组成.结果表明,A12O3的加入通过固相反应来影响钙基固硫效率,A12O3对固硫效率的影响并非呈单一性;低温下生成Ca-Al酸盐矿物削弱了固硫反应,而高温下CaSO4与灰中生成的含Ca、Al类矿物反应形成高温固硫物相硫铝酸钙并抑制其分解则提高了钙基固硫效率.     

New generation of fire retardant polyester resins

Smoke evolution [in a smoke chamber (750 x 750 x 1000) ± 5 mm, Polish Standard PN-91/K-02501 equivalent to UIC 561-OR (1991)] was studied in, and the oxygen index flammability test (Polish Standard PN-76/C-89020) was carried out for, glass-reinforced polyester (GRP) laminates obtained with unsaturated polyester (UP) resins containing chlorine and bromine in the chain. In these studies, the effect on these properties of such additives as ZnSnO₃ (ZS), ZnSn(OH)₆ (ZHS), Al(OH)₃ or Mg(OH)₂ and Sb₂O₃ in an amount of up to 30 mass-% was determined. The most efficient ignition and smoke-evolution retarder from among the investigated compounds was ZS and ZHS, whereas an essential reduction in smoke evolution was observed also with Sb₂O₃. GRP laminates with these additives meet the fire-safety recommendations concerning smoke evolution from materials used in transportation means and in the building industry.