Friction and wear mechanisms of PA66/PPS blend reinforced with carbon fiber

The mechanical and tribological properties of carbon fiber (CF) reinforced polyamide 66 (PA66)/polyphenylene sulfide (PPS) blend composite were studied in this article. It was found that CF reinforcement greatly increases the mechanical properties of PA66/PPS blend. The friction coefficient of the sample decreases with the increase of CF content. When CF content is lower (below 30%), the wear resistance is deteriorated by the addition of CF. However, the loading of higher than 30% CF significantly improves the tribological properties of the blend. The lowest friction coefficient (0.31) and the wear volume (1.05 mm³) were obtained with the PA66/PPS blend containing 30% CF. The transfer film and the worn surface formed by sample during sliding were examined by scanning electron microscopy. The observations revealed that the friction coefficient of PA66/PPS/CF composite depends on the formation and development of a transfer film on the counterface. The abrasive wear caused by ruptured CFs (for lower CF content) and the load bearing ability of CFs (for higher CF content) are the major factors affecting the wear volume. In addition, the improvements of mechanical properties, thermal conductivity, and self‐lubrication of bulk CFs are also contributed to the wear behavior of PA66/PPS/CF composite. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

偶联剂对 PPS/PA66/T-ZnOw 复合材料力学性能的影响

采用硅烷偶联剂KH-560和钛酸酯偶联剂TM-38S对四针状氧化锌晶须(T-ZnOw)进行表面改性,制备了相应的聚苯硫醚(PPS)尼/龙(PA)66/T-ZnOw复合材料,研究了两种偶联剂及其复合体系对T-ZnOw表面改性效果和相应复合材料力学性能的影响,并利用扫描电子显微镜对复合材料的断面形态进行了观察。结果表明,钛酸酯偶联剂TM-38S对T-ZnOw的表面改性效果要优于硅烷偶联剂KH-560;两种偶联剂均提高了复合材料的拉伸强度、断裂伸长率和缺口冲击强度,但对复合材料的弯曲强度影响不大。其中TM-38S改性T-ZnOw与PPS/PA66复合后所得材料的力学性能优于KH-560改性T-ZnOw的材料。两种偶联剂的复合体系虽然可以弥补KH-560副反应对T-ZnOw表面改性的不利影响,但对改善复合材料力学性能的协同作用不明显。     

玻纤增强PA66/PBT合金的相形态及力学性能研究

通过熔融共混法制备了玻纤增强聚己二胺己二酸(PA66)/聚对苯二甲酸丁二醇酯(PBT)合金,研究了自制相容剂对玻纤增强PA66/PBT合金力学性能及相形态的影响。DSC及SEM结果表明,加入5%自制容剂能有效增容PA66和PBT,减少分散相的相尺寸,使合金的力学性能特别是合金的冲击性能达到甚至超过玻纤增强PA66的力学性能,同时合金的吸水率随合金体系中PBT用量的增加而大幅降低。     

PPS/PA66共混物的结构与性能研究

为了制备燃油汽车发动机用新型塑料进气歧管,制备了几种不同配比的PPS/PA66共混物,并对其结构与性能进行了研究。DSC分析表明,PPS/PA66共混物出现了两组分的结晶熔融峰,当共混体系中PA66的质量分数低于60%时,共混物中的PA66破坏了PPS的结晶环境,PPS的结晶度降低,其拉伸强度也随之降低;随着PA66含量的增加,共混物的结晶度提高,拉伸强度和断裂伸长率也得到了相应的提高。SEM及红外光谱分析表明,随组分含量的变化,共混体系发生了相的转变。     

Mechanical and tribological properties of PA66/PPS blend. III. Reinforced with GF

Based on previous work, 70 vol % PA66/30 vol % PPS blend was selected as a matrix, and the PA66/PPS blend reinforced with different content of glass fiber (GF) was prepared in this study. The mechanical properties of PA66/PPS/GF composites were studied, and the tribological behaviors were tested on block‐on‐ring sliding wear tester. The results showed that 20–30 vol % GF greatly increases the mechanical properties of PA66/PPS blend. When GF content is 20 vol %, the friction coefficient of composite is the lowest (0.35), which is decreased by 47% in comparison with the unfilled blend. The wear volume of the GF‐reinforced PA66/PPS blend composite decreases with the increase of GF content. However, the wear‐resistance is not apparently improved by the addition of GF in the experimental range for comparison with unfilled PA66/PPS blend. The worn surface and the transfer film on the counterface were examined by scanning electron microscopy (SEM). The observations revealed that the friction coefficient of composite depends on the formation and development of a transfer film. The wear mechanism involves polymer matrix wear and fiber wear. The former consists of melting wear and plastic deformation of the matrix, while the latter includes fiber sliding wear, cracking, rupturing, and pulverizing. The contributions of the matrix wear and the fiber wear determine the ultimate wear volume of PA66/PPS/GF composite. In addition, the abrasive action caused by the ruptured glass fiber is also a very important factor. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 523–529, 2006     

Compatibilization of ethylene/maleic anhydride/glycidyl methacrylate terpolymer for poly(phenylene sulfide)/poly(amide‐66) blends

In this article, a terpolymer of ethylene, maleic anhydride, and glycidyl methacrylate (EMG) was used to enhance the compatibilization between poly(phenylene sulfide) (PPS) and polyamide‐66 (PA66). The mechanical properties, morphology, crystalline and melting behavior, and rheology of blends were discussed. The results showed that EMG was a good compatibilizer for PPS and PA66 through chemical reaction with them. The new generated polymer could prevent the aggregation of dispersed particles and reinforce the interface bonding. In addition, it could not only act as a nucleating agent for PA66 to refine its spherulites and improve its crystallinity but also promote the apparent viscosity of blends and enhance the non‐Newtonian behavior. The results will be useful to make high performance PPS/PA66 alloy with low cost and enlarge the application scope of PPS and PA66 resin. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

PPS/PA66/HNTs复合材料的制备与性能研究

采用熔融共混方法制备了聚苯硫醚(PPS)/尼龙-66(PA66)/埃洛石纳米管(HNTs)复合材料,研究了其力学性能、热性能及其微观形态.结果表明:当PPS/PA66的比为60/40、HNTs的含量为30%时,复合材料具有较好的性能.复合材料的拉伸强度、弯曲模量及缺口抗冲击强度相对纯PPS分别提高了36.6%、163....     

碳纤维增强尼龙66的研究

利用HAAKE流变仪研究了碳纤维增强尼龙66的流变特性,以及温度对碳纤维增强尼龙66流变性能的影响,并测试了碳纤维增强尼龙66的力学性能。结果表明,碳纤维增强尼龙66在一定剪切速率下,剪切应力下降,表观粘度降低,并且随着剪切速率增加,表观粘度提高;当挤出机头温度升高时,在一定剪切速率下,其剪切应力和表观粘度都降低。而制品的硬度、冲击强度和拉伸强度等力学性能均比纯尼龙66有明显的提高。     

The Effect of Arylboronic Acid Treatment of Carbon Fiber on the Mechanical and Tribological Properties of PA66 Composites

PA66 composites filled with surface-treated carbon fiber were prepared by twin-screw extruder in order to study the influence of carbon fiber surface arylboronic acid treatment on the mechanical and tribological behavior of the PA66 composites (CF/PA66). The mechanical property, friction and wear tests of the composites with untreated and treated carbon fiber were performed and the worn surface morphology was analyzed. The results show that the worn surface area of the treated carbon fiber was far smoother than that of the untreated carbon fiber and there formed a bonding adhesion on the carbon fiber surface after treatment. The tensile strength of CF/PA66 composites with surface arylboronic acid treatment was improved. The friction coefficient and wear of arylboronic acid treated CF/PA66 composites were apparently lower than that with untreated carbon fiber. In conclusion, the surface treatment favored the improvement of the higher interface strength and so had good effect on improving the tribological properties of the composites.     

EPDM/PA高性能弹性体配合体系的研究

研究了ＥＰＤＭ／三元共聚尼龙（ＰＡ）高性能弹性体共混体系中各组分及配合剂用量对该体硫化胶物理性能的影响。结果一明,ＥＰＤＭ用量为７０份时,ＰＡ用量以３０份为宜,炭黑用量宜为ＥＰＤＭ用量的一半;ＥＰＤＭ及ＰＡ的品种对共混物的加工性能及物理性能有明显的影响,硫化体系宜采用过氧化物及助交联剂并用体系,液体古马隆树脂是该共混体系适宜的软化剂。     

Mechanical and tribological properties of PA66/PPS blend. II. Filled with PTFE

The mechanical and tribological properties of 70 vol % PA66/30 vol % PPS blend filled with different content of polytetrafluoroethylene (PTFE) were studied in this paper. It was found that the addition of PTFE impairs the mechanical properties of PA66/PPS blend, but greatly increases the wear resistance and decreases the friction coefficient. When PTFE content exceeds 20 vol %, the friction coefficient of composite is minimum (0.15) and lower than that of pure PTFE under the same conditions (0.22). The lowest wear volume (0.44 mm³) is obtained with PA66/PPS/30 vol % PTFE composite, which decreased by 91% compared with unfilled PA66/PPS blend (4.99 mm³). The topography of transfer film and the elemental distribution were investigated by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS), respectively. Because of the characteristic crystalline structure, PTFE preferentially transferred to the steel ring surface and formed a thin, uniform and firmly adhered transfer layer, which reduced the ability of PA66/PPS blend to transfer and prevent the adhesion between the sample and the couterface. In addition, the superior lubrication of PTFE inhibited the frictional heat melting during sliding. All these aspects are close related to the friction and wear behavior of PA66/PPS/PTFE composite. Upon the addition of PTFE, thermal control of friction regime is not applicable to the PA66/PPS blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 969–977, 2006     

Synthesis and properties of reactively compatibilized polyester and polyamide blends

The functionalization of poly(butylene terephthalate) (PBT) has been accomplished in a twin screw extruder by grafting maleic anhydride (MA) using a free radical polymerization technique. The resulting PBT‐g‐MA was successfully used as a compatibilizer for the binary blends of polyester (PBT) and polyamide (PA66). Enhanced mechanical properties were achieved for the blend containing a small amount (as low as 2.5 %) of PBT‐g‐MA compared to the binary blend of unmodified PBT with PA66. Loss and storage moduli for blends containing compatibilizer were higher than those of uncompatibilized blends or their respective polymers. The grafting and compatibilization reactions were confirmed using FTIR and ¹³C NMR spectroscopy. The properties of these blends were studied in detail by varying the amount of compatibilizer, and the improved mechanical behaviour was correlated with the morphology with the help of scanning electron microscopy. Morphology studies also revealed the interfacial interaction in the blend containing grafted PBT. The improvement in the properties of these blends can be attributed to the effective interaction of grafted maleic anhydride groups with the amino group in PA66. The results indicate that PBT‐g‐MA acts as an effective compatibilizer for the immiscible blends of PBT and PA66. © 2000 Society of Chemical Industry     

碳纤维增强尼龙66复合材料的制备及性能

采用双螺杆挤出机熔融共混法制备了碳纤维(CF)增强尼龙66复合材料(PA66/CF),对其结构进行了表征,并研究了其力学性能。扫描电镜照片显示,在PA66/CF复合材料中,CF与PA66基体充分粘结在一起,其微观形貌表明,体系中碳纤长度为0.5~0.7 mm。力学性能测试发现,与尼龙66相比,PA66/CF复合材料各项力学性能指标均有大幅度提高。当加入4束碳纤维时,PA66/CF复合材料力学性能最佳,该复合材料的拉伸强度为200.2 MPa,与PA66相比提高了113.2 MPa;弯曲强度为280.2 MPa,比PA66提高了190.3 MPa;弯曲模量为13560.8 MPa,比PA66提高了10628.7 MPa;冲击强度为14.8 kJ/m^2,比与PA66提高了6.3 kJ/m^2。该PA66/CF复合材料密度较小、力学性能优良,可以广泛应用于风电叶片、发动机罩盖、仪表盘、车尾门等产品当中。     

PPS/PA66/GF复合材料的制备及性能研究

在聚苯硫醚（PPS）树脂基体中引入聚酰胺66（PA66）,随着PA66含量增加,PPS/PA66共混物的拉伸强度和弯曲强度逐渐下降,结合PPS/PA66共混物的相形貌分析,提出了通过玻璃纤维（GF）的引入,制备具有互锁结构的PPS/PA66/GF三元体系复合材料,达到同时提高复合材料的强度、刚度及韧性的目的。分别考察了短玻璃纤维（SGF）和中长玻璃纤维（LGF）增强PPS/PA66的综合性能。结果表明,GF的引入显著提高了共混物的力学性能,同时,PPS/PA66/SGF和PPS/PA66/LGF复合材料的扫描电子显微镜和动态力学性能分析都表明共混物内部形成了一个高度互锁的结构。     

Manipulating the phase morphology in PPS/PA66 blends using clay

By adding a small amount of clay into poly(p‐phenylene sulfide) (PPS)/polyamide 66 blends, the morphology was found to change gradually from sea–island into cocontinuity and lamellar supramolecular structure, as increasing of clay content. Clay was selectively located in the PA66 phase, and the exfoliated clay layers formed an edge‐contacted network. The change of morphology is not caused by the change of volume ratio and viscosity ratio but can be well explained by the dynamic interplay of phase separation between PPS and PA66 through preferential adsorption of PA66 onto the clay layers and through layer–layer repulsion. This provides a means of manipulating the phase morphology for the immiscible polymer blends. The mechanical and tribological properties of PPS/PA66 blends with different phase morphologies (different clay contents) were studied. Both tensile and impact strength of the blends were found obviously increased by the addition of clay. The antiwear property was greatly improved for the blends with cocontinuous phase form. Our work indicates that the phase‐separating behavior of polymer blends contained interacting clay can be exploited to create a rich diversity of new structures and useful nanocomposites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Nonisothermal crystallization of polyamide 66/poly(phenylene sulfide) blends

The crystalline morphologies of isothermally and nonisothermally crystallized poly(phenylene sulfide) (PPS) and its blend with polyamide 66 (PA66) were investigated by polarized optical microscopy with a hot stage. The spherulite superstructure of PPS was greatly affected by crystallizable PA66; a Maltese cross was not clear, and the impingement between spherulites disappeared. This could be ascribed to the formation of small crystals of PA66, which filled in the PPS lamellae. The nonisothermal crystallization behavior was also measured by differential scanning calorimetry. The presence of PA66 changed the nonisothermal crystallization process of PPS. The maximum crystallization temperature of the PPS phase in the blend was higher that that of neat PPS, and this indicated that PA66 acted as a nucleus for PPS. Also, the compatibilizer poly(ethylene‐stat‐methacrylate) (EMA) was added to modify the interfacial interplay of the PA66/PPS blend system. The addition of EMA greatly influenced the nonisothermal crystallization process of the PPS phase in the blend system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

电子束辐照对聚对苯二甲酸丁二醇酯的影响

采用电子加速器对聚对苯二甲酸丁二醇酯(PBT)进行辐照,研究了吸收剂量、交联助剂及辐照气氛对PBT凝胶含量的影响,以及辐照交联对PBT力学性能及结晶行为的影响。结果表明,PBT树脂对电子束辐照相对稳定,交联助剂TMPTA能有效促进PBT的辐照交联;辐照后的PBT拉伸强度较未辐照时明显提高,断裂伸长率相应地略有降低;而同一吸收剂量下,交联助剂的添加量对PBT的拉伸强度及断裂伸长率无明显影响;PBT辐照交联后熔点降低,熔融焓减小,形成尺寸较小、结构不完善的晶体。     

PPS/PAI/CF复合材料摩擦磨损性能的研究

采用模压成型法制备了聚苯硫醚(PPS)/聚酰胺酰亚胺(PAI)合金及其碳纤维(CF)改性复合材料。测试分析了该复合材料的力学性能,并通过扫描电镜(SEM)对其摩擦磨损表面形貌进行了观察,探讨了复合材料的摩擦磨损性能;考察了PPS/PAI合金的最优配比及CF含量对PPS/PAI/CF复合材料性能的影响。结果表明:PAI的加入改善了PPS的力学性能,当PPS/PAI质量比为40/60时,PPS/PAI合金的力学性能最优;另外,CF的加入使PPS/PAI/CF填充复合材料的摩擦系数和磨损量大幅度下降,其中,当CF含量为30%时,PPS/PAI/CF填充复合材料的摩擦系数和磨损量较未填充PPS/PAI分别下降了66%和90%。     

Toughening and compatibilization of polyphenylene sulfide/nylon 66 blends with SEBS and maleic anhydride grafted SEBS triblock copolymers

In this study, styrene‐b‐ethylene/butylene‐b‐styrene triblock copolymer (SEBS) and maleic anhydride grafted SEBS (SEBS‐g‐MA) were used as compatibilizers for the blends of polyphenylene sulfide/nylon 66 (PPS/PA66). The mechanical properties, including impact and tensile properties and morphology of the blends, were investigated by mechanical properties measurements and scanning electron microscopy. Impact measurements indicated that the impact strength of the blends increases slowly with elastomer (SEBS and SEBS‐g‐MA) content upto 20 wt %; thereafter, it increases sharply with increasing elastomer content. The impact energy of the elastomer‐compatibilized PPS/PA66 blends exceeded that of pure nylon 66, implying that the nylon 66 can be further toughened by the incorporation of brittle PPS minor phase in the presence of SEBS or SEBS‐g‐MA. The compatibilization efficiency of SEBS‐g‐MA for nylon‐rich PPS/PA66 was found to be higher than SEBS due to the in situ forming SEBS interphase between PPS and nylon 66. The correlation between the impact property and morphology of the SEBS‐g‐MA compatibilized PPS/PA66 blends is discussed. The excellent impact strength of the nylon‐rich blends resulted from shield yielding of the matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Thermal conductivity,electrical resistivity,mechanical, and rheological properties of thermoplastic composites filled with boron nitride and carbon fiber

Hybrid composites consisting of boron nitride (BN) platelets and carbon fibers (CF) in a polybutylene terephthalate (PBT) matrix were melt‐compounded, and their thermal and electrical conductivity, tensile, and rheological properties were investigated. While it does not lead to an enhancement in thermal conductivity with respect to PBT/BN composites, the results indicate that a combination of BN and CF in PBT can significantly reduce electrical conductivity of the composites compared to that of PBT/CF composites. The relative low thermal conductivity of the hybrid composites is attributed to CF breakage that occurred during the extrusion and alignment of CF in melt flow direction, which is normal to the heat flow encountered during the thermal conductivity tests induced by injection molding. The hybrid composites were, however, found to have better tensile properties and processibility than PBT/BN composites at the same total filler content. POLYM. COMPOS., 26:66–73, 2005. © 2004 Society of Plastics Engineers