scholarly journals PAI Materials Synthesized by 4,4′-Diaminodiphenyl Ether/2,2′-Bis (Trifluoromethyl)-4,4′-Diaminophenyl Ether and their Properties

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6376
Author(s):  
Haiyang Yang ◽  
Duxin Li ◽  
Jun Yang ◽  
Jin Wang ◽  
Shunchang Gan

In this paper,4,4′-diaminodiphenyl ether and 2,2′-bis (trifluoromethyl)-4,4′-diaminophenyl ether are selected for molecular structure design, and PAI materials are synthesized by acyl chloride method. 2,2′-bis (trifluoromethyl)-4,4′-diaminophenyl ether has the same main chain structure as 4,4′-diaminodiphenyl ether, but the side chain contains two trifluoromethyl groups, which has high fluorine content. PAI terpolymerswere prepared by compounding two diamine monomers, and the effects of trifluoromethyl on heat resistance, friction and wear properties, hydrophobic properties and mechanical properties of PAI materials were studied. The results showed that with the increase of trifluoromethyl content, the Tg of PAI material first increased and then changed little, and the Td5% would decrease and the tensile properties would also decrease. The wear mechanism of PAI varied with the content of trifluoromethyl. With the increase of the amount of fluorinated diamine monomer, the adhesive wear degree of PAI materials gradually increased, and reached the maximum when the molar ratio of the two monomers was 5:5, and then decreased gradually. Different trifluoromethyl content had little effect on friction coefficient, and the friction coefficient increased slightly when the molar ratio of 4,4′-diaminodiphenyl ether to 2,2′-bis (trifluoromethyl)-4,4′-diaminophenyl ether is 1:9. With the increase of trifluoromethyl content, the wear of PAI material would increase. With the increase of the amount of trifluoromethyl, the water absorption of PAI material decreased and the water contact angle increased, which indicated that the hydrophobic property of PAI material was improved. To sum up, the results of this study showed that the introduction of trifluoromethyl into the side chain provided an effective way to prepare PAI materials with low water absorption. Considering the comprehensive properties such as heat resistance, friction and wear, tensile properties, etc., the appropriate addition amount is 10–30%.


2017 ◽  
Vol 733 ◽  
pp. 60-64
Author(s):  
Munir Tasdemir ◽  
Ozkan Gulsoy

In the present work, the friction and wear properties of Polypropylene (PP) based composites filled with Hydroxyapatite (HA) particles were studied. Fillers contents in the PP were 10, 20, and 30 wt%. The effects of hydroxyapatite ratio on the water absorption, friction and wear properties of the polymer composites is presented. The result showed that the addition of HA to the composite changed the water absorption, friction coefficient and wear rate.



2014 ◽  
Vol 941-944 ◽  
pp. 1612-1615
Author(s):  
Rui Min Sun ◽  
Hui Zhao ◽  
Yong Heng Zhou

PAI/SiC-and PAI/SiC/PTFE-composite coatings were prepared, which were deposited on Al substrates using spraying technology to improve their surfaces performance. Friction and wear of PAI composite coatings were evaluated on a ball-on-block wear tester, and thermal properties were investigated by TG. It is found that, the friction coefficient and wear rate of PAI coatings reaches the best value when the content of SiC and PTFE is 10 wt % and 0.8wt% respectively, and the friction coefficient of the composites coatings decrease but the wear rate increase with increasing applied load; TG curves shows that the PAI composite coatings have excellent heat resistance. Furthermore, the surface of PAI coatings is perfect without bubbling, desquamating and cracking when it is heated for 2 hour at 250◦C in turn three cycles.



2015 ◽  
Vol 713-715 ◽  
pp. 223-227 ◽  
Author(s):  
Jie Li ◽  
Xiao Yan Wang ◽  
Zhi Yong Wang

The thermal distortion of friction pair will be produced in high line speed frictioning. For solving interaction theory from this problem, thermal distortion micro-bulges model of two interaction friction surfaces is built by ways of micro-interaction dynamics, and equations of contact forces of micro-bulges are obtained. By using mathematic statistics and normalization, equations of macro-normal and tangential contact forces are obtained, and relation between friction coefficient and micro-parameters is found. Contact forces and friction coefficient characteristics expressed by parameters of dimensionless clearance and curvature are simulated. The results show that the interaction theory is important in deeper understanding friction and wear theory in high line speed running, and offers reliable proof for future finer structure design of friction pair and model design of clutch.



Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  

Abstract AISI Type 308 is an austenitic chromium nickel steel with corrosion and heat resistance superior to Type 304. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-140. Producer or source: Alloy steel mills and foundries.



2021 ◽  
pp. 089270572110286
Author(s):  
Xinyue Zhang ◽  
Dekun Zhang ◽  
Kai Chen ◽  
Handong Xu ◽  
Cunao Feng

The complex movement of artificial joints is closely related to the wear mechanism of the prosthesis material, especially for the polymer prosthesis, which is sensitive to motion paths. In this paper, the “soft-soft” all-polymer of XLPE/PEEK are selected to study the influence of motion paths on the friction and wear performance. Based on the periodic characteristics of friction coefficient and wear morphology, this paper reveals the friction and wear mechanism of XLPE/peek under multi-directional motion path, and obtains the quantitative relationship between friction coefficient and the aspect ratios of “∞”-shape motion path, which is of great significance to reveal and analyze the wear mechanism of “soft” all-polymer under multi-directional motion path. The results show that the friction coefficient is affected by the motion paths and have periodicity. Morever, under the multi-directional motion paths, the wear of PEEK are mainly abrasive wear and adhesive wear due to the cross shear effect, while the wear of XLPE is mainly abrasive wear with plastic accumulation. In addition, the friction coefficient is greatly affected the aspect ratios Rs-l of “∞”-shape and loads. Meanwhile, the wear morphologies are greatly affected by the aspect ratios Rs-l of “∞”-shape, but less affected by loads.



Lubricants ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 54
Author(s):  
Valdicleide Silva Mello ◽  
Marinalva Ferreira Trajano ◽  
Ana Emilia Diniz Silva Guedes ◽  
Salete Martins Alves

Additives are essential in lubricant development, improving their performance by the formation of a protective film, thus reducing friction and wear. Some such additives are extreme pressure additives. However, due to environmental issues, their use has been questioned because their composition includes sulfur, chlorine, and phosphorus. Nanoparticles have been demonstrated to be a suitable substitute for those additives. This paper aims to make a comparison of the tribological performance of conventional EP additives and oxides nanoparticles (copper and zinc) under boundary lubrication conditions. The additives (nanoparticles, ZDDP, and sulfur) were added to mineral and synthetic oils. The lubricant tribological properties were analyzed in the tribometer HFRR (high frequency reciprocating rig), and during the test, the friction coefficient and percentual of film formation were measured. The wear was analyzed by scanning electron microscopy. The results showed that the conventional EP additives have a good performance owing to their anti-wear and small friction coefficient in both lubricant bases. The oxides nanoparticles, when used as additives, can reduce the friction more effectively than conventional additives, and displayed similar behavior to the extreme pressure additives. Thus, the oxide nanoparticles are more environmentally suitable, and they can replace EP additives adapting the lubricant to current environmental requirements.



2006 ◽  
Vol 306-308 ◽  
pp. 417-422 ◽  
Author(s):  
Hyo Jin Kim ◽  
Do Won Seo ◽  
Jae Kyoo Lim ◽  
Toru Fujii


2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.



2011 ◽  
Vol 80-81 ◽  
pp. 60-63
Author(s):  
Xue Qing Yue ◽  
Hua Wang ◽  
Shu Ying Wang

Incorporation of metallic elements, titanium and copper, into carbonaceous mesophase (CM) was performed through mechanical alloying in a ball mill apparatus. The structures of the raw CM as well as the Ti/Cu-added CM were characterized by X-ray diffraction. The tribological behavior of the Ti/Cu-added CM used as lubricating additives was investigated by using a high temperature friction and wear tester. The results show that, compared with the raw CM, the Ti/Cu-added CM exhibits a drop in the crystallinity and a transition to the amorphous. The Ti/Cu-added CM used as lubricating additive displays an obvious high temperature anti-friction and wear resistance effect, and the lager the applied load, the lower the friction coefficient and the wear severity.



2017 ◽  
Vol 25 (9) ◽  
pp. 683-688 ◽  
Author(s):  
Xueqin Kang ◽  
Chi Yao ◽  
Lei Qiao ◽  
Gaofeng Ge ◽  
Peizhong Feng

The present study was designed to investigate the mechanical performance of ultra high molecular weight polyethylene (UHMWPE) reinforced by silver nanoparticles. The Ag/UHMWPE nanocomposites were prepared by a plate vulcanizing machine and tested with a contact angle micrometer, UMT friction tester, electronic universal testing machine and MicroXAM three-dimensional profilometer to characterise the wettability, ball indentation hardness, creep resistance, compression properties, and friction and wear performance. A scanning electron microscope (SEM) was employed to describe the morphology of the Ag/UHMWPE nanocomposites surfaces following the friction and wear tests. These results demonstrate that the compressive yield strength, ball indentation hardness and creep resistance increased with an increase in the content of silver nanoparticles. The contact angle of the Ag/UHMWPE nanocomposites with bovine calf serum decreases with an increase in the content of silver nanoparticles and this change increases the wettability of the Ag/UHMWPE nanocomposites. Therefore, the friction coefficient decreases, but the wear mechanism changes from scratch and furrow to fatigue flakes when the mass fraction of silver nanoparticles exceeds 0.3%. The composite with a silver nanoparticles mass fraction of 0.3% exhibits a low friction coefficient and good wear resistance.



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