红外加热缠绕成型工艺参数对CF/PEEK复合材料层间剪切性能的影响

为获得层间粘结性能优异的连续碳纤维增强聚醚醚酮复合材料(CF/PEEK)缠绕成型制品,以粉末浸渍法制备的CF/PEEK单向带为原料,采用自制的高功率红外加热热塑性复合材料缠绕成型设备,进行缠绕成型工艺的研究。以层间剪切强度(ILSS)作为评价缠绕制品性能的主要依据,分别研究了缠绕成型过程中的送料张力、下压辊压力、缠绕速率、加热温度、预热时间和冷却速率等关键工艺参数对CF/PEEK环制品性能的影响。实验结果表明,成型温度为410℃,预热为40 min,送料张力为8 kg,下压辊气缸压力为0.30 MPa,芯模转速为6 r/min,缓慢冷却条件下制得的缠绕制品性能最优,层间剪切强度达到(82.29±1.27) MPa,并据此制备出了CF/PEEK缠绕管道。     

纳米Al2O3改性树脂基复合材料及体育应用性能

针对传统树脂基复合材料力学性能差,抗冲击性低等问题,以纳米Al₂O₃、CFF和PA6为原料,采用传统叠层模压的方式,制备一种体育器材用的层压板,并对制备层压板的力学性能和最佳工艺进行了探讨。结果表明,在模压温度230℃,热压压力3MPa,保压时间15min的条件下,制备的层压板力学性能最佳,其弯曲强度、层间剪切强度和缺口冲击强度分别达到250.3MPa、87.1MPa和56.1MPa;在加入6%（wt）的纳米Al₂O₃后,层压板弯曲强度和垂直于纤维铺层方向的冲击强度分别在最佳力学性能基础上达到387.6MPa和80.3MPa。     

聚丙烯自增强复合材料层压板的制备和性能研究

以聚丙烯树脂为基体,聚丙烯纤维织物为增强体,采用层压成型工艺制备了聚丙烯自增强复合材料层压板。研究了成型温度、成型压力、成型时间和纤维含量等工艺参数对聚丙烯自增强复合材料层压板拉伸和弯曲性能的影响规律,并采用差示扫描量热(DSC)仪和扫描电子显微镜(SEM)对其进行了热分析和形态结构的表征。结果表明,当成型温度为175℃,成型压力为10 MPa,成型时间为15 min,纤维含量为60%时,聚丙烯自增强复合材料层压板的力学性能达到最大值,其拉伸强度为(125.76±0.77)MPa,弯曲强度和弯曲弹性模量分别为(30.77±0.70)MPa和(1 795.46±75.95)MPa;从DSC图和SEM图观察到成型温度为175℃时聚丙烯纤维表面发生了熔融,有利于纤维和树脂之间的界面粘结力的增强。     

连续碳纤维增强聚醚醚酮板材的研究

采用自行设计、组装的连续纤维增强热塑性树脂基复合材料粉末浸渍试验装置制备了连续碳纤维(CF)增强聚醚醚酮(PEEK)预浸带,再将浸渍带通过热压模塑成型制备出层合板材。通过万能材料试验机、悬臂梁冲击试验机研究了纤维含量和浸渍带铺放方式对板材力学性能的影响。结果表明,在一定范围内CF/PEEK板材弯曲、冲击强度随着纤维含量的增大而提高,拉伸强度达1 124. 89 MPa,约是PEEK纯料的11倍,浸渍带以0°铺放压制的纤维含量为60%的板材力学性能相对最优。扫描电子显微镜(SEM)结果表明,纤维被树脂基体紧密包覆,纤维分散均匀、排列紧密、界面黏结性较好。     

混杂纤维复合材料力学性能及其低速冲击性能研究

采用热压成型工艺制备单一碳纤维、碳纤维/玻璃纤维(CF/GF)和碳纤维/Kevlar纤维(CF/KF)均质和非均质混杂增强环氧树脂基复合材料,通过三点弯曲、层间剪切、低速冲击及冲后压缩性能测试,研究纤维组分、混杂结构和混杂比对复合材料力学性能及低速冲击性能的影响。结果表明,单一碳纤维复合材料力学性能最佳,其弯曲模量、弯曲强度和层间剪切强度分别达到66.16 GPa、830.35 MPa和42.73 MPa,而CF/GF混杂结构性能总体优于CF/KF混杂结构,内层混杂结构性能优于外层混杂结构;单一碳纤维复合材料低速冲击性能较差,其冲击损伤凹坑深度最高可达混杂结构的3.5倍,对应的分层阈值为2 723.53 N;CF/KF均质混杂结构的剩余压缩强度最大,而单一碳纤维复合材料则最小,对应数值分别为0.92和0.79。     

PPS/GF混纤纱复合材料的制备及力学性能研究

制备了混纤纱结构的聚苯硫醚（PPS）/玻璃纤维（GF）织物,通过模压成型制备复合材料层压板。研究了质量含量为20 % PPS和80 % GF的复合材料的成型温度、成型时间等因素对复合材料层压板力学性能的影响。通过扫描电子显微镜对不同工艺条件下复合材料的微观形貌进行了观察, 研究了工艺条件对空隙的影响规律。结果表明,在成型温度为320 ℃、成型压力为2.0 MPa,成型时间为10 min时,连续PPS/GF复合材料层压板的力学性能达到最优值,其拉伸和弯曲强度分别为（502.9±2.9）、(530.1±5.6) MPa。     

连续玻纤增强聚丙烯混纤纱织物层压成型工艺研究

采用两种不同形式的混纤纱机织物为原料,利用层压成型的方法制备了连续玻璃纤维(GF)增强的聚丙烯(PP)板材。研究了层压温度、压力、保压时间和混纤纱机织物形式对层压板材的弯曲性能和层间剪切强度(ILSS)的影响。结果表明,当层压温度为230℃,层压压力为8.5 MPa,保压时间为30 min,降温过程冷却速度为0.5℃/min时,层压板材的力学性能最佳。弯曲强度和模量分别达到352.58 MPa、23.09 GPa,ILSS达到27.37 MPa。此时,纤维含量和空隙率分别为72.25%、2.03%。在最优工艺条件下制备的两种不同织物形式层压板材弯曲强度和弯曲模量以及ILSS:2/2斜纹织物平纹织物。两种织物层压板材的空隙率:2/2斜纹织物平纹织物。     

模压成型工艺参数对CF/PEEK复合材料Ⅰ型层间断裂韧性的影响

连续碳纤维增强聚醚醚酮(CF/PEEK)复合材料是重要的医疗器械及航空航天热塑性复合材料,可采用模压成型工艺制备层合板及结构,其工艺参数影响复合材料力学性能。本文主要考察了模压成型温度、压力以及降温速率等参数对CF/PEEK复合材料Ⅰ型层间断裂韧性(GIC)的影响规律,并通过扫描电镜表征复合材料撕裂面的微观形貌,分析材料失效模式。较高的模压成型温度可提高基体分子链流动性,适中的成型压力有利于控制树脂不被过多挤出模具,适中的降温速率可降低结晶度并抑制界面粘结强度的损失,均有利于提高CF/PEEK复合材料的GIC。     

碳纤维增强聚苯硫醚复合材料结晶结构与性能调控

使用碳纤维斜纹布与聚苯硫醚(PPS)薄膜通过热压成型制备了碳纤维增强PPS (PPS/CF)复合材料层压板,通过在保温保压过程中设置不同的等温结晶温度,对复合材料中PPS结晶结构进行调控,系统讨论了不同等温结晶温度下,PPS结晶度及晶粒尺寸对PPS/CF复合材料力学性能的影响。使用X射线衍射仪观察了复合材料中PPS的晶体结构,通过场发射扫描电子显微镜观察了复合材料的微观形貌,并利用动态机械分析测试探究了复合材料的黏弹性与PPS晶体结构之间的关系。结果表明,当等温结晶温度为230℃时,复合材料中PPS在保持较小晶粒尺寸的同时结晶度高达46.58%,此时复合材料具有良好的强度、刚性和界面粘结强度,其弯曲强度、弯曲弹性模量和层间剪切强度分别达到709 MPa,81.9 GPa和23.8 MPa。     

无机颗粒/碳纤维共增强聚酰胺6复合材料的制备与力学性能研究

采用熔融挤出法制备出无机颗粒(IP)增强聚酰胺6(PA6)复合材料,使用叠层模压法制备了IP/碳纤维(CF)共增强PA6复合材料(PA6/IP/CF)。利用场发射扫描电子显微镜、万能试验机等研究了IP的形貌和含量对复合材料性能的影响。结果表明,当滑石粉(TALC)的添加量达到10%(质量分数,下同)时,PA6/CF/TALC复合材料的各项力学性能达到最大值,弯曲强度为374.6 MPa、剪切强度为58.7 MPa、冲击强度为76.9 kJ/m~2;当玻璃微珠(GB)的添加量达到15%时,PA6/CF/GB复合材料的各项力学性能达到最大值,弯曲强度为404.4 MPa、剪切强度为66.7 MPa、冲击强度为86.5 kJ/m~2;GB相较于TALC对复合材料的增强效果更好,使复合材料的综合力学性能得到进一步提高。     

Improvement of interfacial interactions in CF/PEEK composites by an s-PSF/graphene oxide compound sizing agent

The interfacial interactions of carbon fiber (CF)-reinforced polymer composites is a key factor affecting the overall performance of the material. In this work, we prepared a sulfonated poly(ether sulfone)–graphene oxide mixed sizing agent to modify the interface of CF/PEEK composites and improve the interfacial properties between the PEEK matrix and CF. Results showed that the mechanical and interfacial properties of CF/PEEK composites are improved by the sizing agent. Specifically, the flexural strength, flexural modulus and interlaminar shear strength of the materials reached 847.29 MPa, 63.77 GPa, and 73.17 MPa, respectively. Scanning electron microscopy confirmed markedly improved adhesion between the resin matrix and fibers. This work provides a simple and effective method for the preparation of high-performance CF/PEEK composites, which can improve the performance of composites without degrading the mechanical property of pristine CF.     

Mechanical properties of glass fabric/polyester composites: Effect of silicone coatings on the fabrics

An experimental investigation was carried out to study the effect of a silicone coating on the mechanical properties of polyester/woven glass fabric composites, fabricated by resin transfer molding. E‐glass woven fabrics were coated with a silicone elastomer by solution dip coating. The effect of variation of silicone amounts on the impact resistance, toughness, and mechanical properties of the composite was determined. Short beam shear tests were performed to assess the effect of coating on the adhesion of the fiber to the matrix. The coated specimens exhibited worse interlaminar shear strength over that of uncoated fabrics. Three‐point bending tests were also performed to investigate the effect of the coating on flexural properties. Whereas flexural strength and Young's modulus decreased with increasing amount of coating, the toughness, represented by the area under the stress–strain curve, presented a maximum. Finally, notched Izod impact tests were carried out and the curve for the energy absorbed during impact versus the amount of coating also appeared to have a maximum, indicating an interesting slot for optimum impact performance. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1300–1308, 2004     

界面结合对GF/PDCPD复合材料性能的影响

界面结合性能对制备性能优异的复合材料具有重要意义。通过对双环戊二烯（DCPD）与玻璃纤维（GF）的浸润性进行研究，将其与等效环氧树脂比较，开发了一种与玻璃纤维具有较好结合性的DCPD树脂，用其制备出一种综合性能优异的玻璃纤维增强PDCPD基复合材料。通过动态接触角、90?拉伸强度和层间剪切强度实验，测定了不同树脂与玻璃纤维之间的粘附力，提供了玻璃纤维与不同树脂界面性能差异。结果表明，SCB-600 DCPD树脂与玻璃纤维的结合性较优，动态接触角为60.35??0.3?，90?拉伸强度为(42.3?1.6) MPa，层间剪切强度为(61.3?3.2) MPa，与1564环氧树脂相当。进一步优化了DCPD树脂质量分数，当树脂质量分数为30%?2%时，SCB-600 DCPD复合材料具有相对最优的力学性能，材料拉伸强度为(1180.1?4.1) MPa，弯曲强度为(1060.4?4.6) MPa，缺口冲击强度为(145.3?4.8) KJ/m2。其弯曲和拉伸强度与玻璃纤维增强环氧树脂基复合材料的性能基本相当，但缺口冲击强度优于1564环氧树脂。     

The improved interface performance between carbon fiber and poly(ether-ether-ketone) by sulfonated polyether sulfone (s-PSF) sizing agent with different sulfonation degree

The effects of sulfonated polyether sulfone (s-PSF) with different sulfonation degrees on the interfacial properties of carbon fiber (CF)/poly(ether-ether-ketone) (PEEK) composites were investigated systematically. The performance of the modified CF and the corresponding CF/PEEK composites and was tested and characterized. Test results show that the CF surface polarity increases, the surface contact angle decreases, and the surface free energy increases with the increase in the s-PSF sulfonation degree. Scanning electron microscopy analysis shows that the increase in the sulfonation degree of s-PSF is beneficial to improve the interface between CF and PEEK. This condition can be ascribed to the hydrogen bonding force between the s-PSF sulfonic acid group and the polar functional group on the surface of the modified CF and the compatibility between s-PSF and PEEK. In terms of physical properties, the thermal and mechanical properties of CF/PEEK composite are improved with the increase in s-PSF sulfonation degree. The interlaminar shear strength, flexural strength, and modulus of CF/PEEK composites increase by 60.16%, 30.27%, and 19.30%, respectively.     

Study on mechanical properties of powder impregnated glass fiber reinforced poly(phenylene sulphide) by injection molding at various temperatures

The prepreg of continuous glass fiber reinforced poly(phenylene sulphide) (PPS) was prepared using the powder impregnation technique and cut into the pellets, in which the length of glass fibers was the same as the pellets. After injection molding, the mechanical properties were tested and the effects of the pellet length, fiber content, and thermal treatment on the mechanical properties at different temperatures were studied. It is found that the tensile strength and flexural strength of 6‐mm pellet sample are slightly higher than that of 3‐ and 12‐mm pellet samples. The tensile strength, flexural strength, and modulus decrease significantly with increasing the temperature. The notched Izod impact strength at 85ºC is higher than both at 25ºC and 205ºC. At 205ºC, the glass fiber reinforced PPS composites can still keep better mechanical properties. When the fiber content ranges from 0 to 50%, the mechanical properties increase with increasing the fiber contents at different temperatures, except the notched Izod impact strength do not further increase at 145 and 205ºC with raising the fiber content from 40 to 50%. Thermal treatment could improve the mechanical properties of the composites at higher serving temperature. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Enhanced mechanical and electrical properties of carbon fiber/poly(ether ether ketone) laminates via inserting carbon nanotubes interleaves

The carbon fiber/(carbon nanotubes/polyetherimide)/poly ether ether ketone (CF/(CNTs/PEI)/PEEK) laminates are prepared by inserting carbon nanotubes/polyetherimide (CNTs/PEI) interleaves into interlaminar region. The mechanical properties and electrical conductivities of the developed laminates are evaluated. The results indicate that the interlaminar shear strength and flexural strength of CF/(CNTs/PEI)/PEEK laminates are increased by 42.9% and 24.7%, after inserting CNTs2.91/PEI interleaves, respectively. The cross-sectional images of laminates after mechanical tests verify strong fiber-resin adhesion by scanning electron microscope observation. The pertinent mechanism responsible for the improvement of mechanical properties is mechanical interlocking effect of CNTs. After incorporating CNTs/PEI interleaves, the electrical conductivity of laminates is markedly improved due to the formation of conductive pathway. This work suggests that this method is compatible with the preparation process of thermoplastic composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48658.     

Long fiber reinforcement of polypropylene/polystyrene blends

The recycling of inseparable polymer mixtures usually results in blends with poor mechanical properties. A mixture of PP and PS was taken as a model compound for a recyclate. The effect of adding glass fibers to a mixture of PP/PS (70/30) was studied, with special attention to long glass fiber reinforcement. Test specimens were made in three different ways: by dry blending (direct injection molding), mild compounding with a single screw extruder, and compounding with a twin screw extruder. The fiber concentration was varied from 0 to 30 wt%. The fiber lengths were determined to investigate fiber attrition. The fiber lengths in the samples were 1.09 mm for dry blending, 0.72 mm for single screw compounding, and 0.33 mm for twin screw compounding. The mechanical behavior was studied by unnotched and notched Izod impact and tensile tests. The PP/PS blend had a low fracture strain and low unnotched Izod impact strength compared with a PP homopolymer. With an increasing fiber concentration and fiber length, the modulus, tensile strength, and particularly the impact strength increased. With a 30 wt% glass fiber of the long fiber compound (dry blended), the modulus was raised by a factor of 3.5, the fracture stress by a factor of 2.5 and the unnotched Izod impact strength by a factor of 10. The product quality as judged by the scatter of the data was best for the twin screw compound and poorest for the dry blend. Compounding with a single screw extruder gave fairly constant injection molding product properties, combined with excellent mechanical properties.     

PEEK层间增韧碳纤维环氧树脂基复合材料的性能研究

为了改善碳纤维/环氧树脂(CF/EP)层合板层间断裂韧性较差的问题,采用预浸料层间涂层和模压工艺制备聚醚醚酮(PEEK)层间增韧CF/EP层合板。探究PEEK含量对CF/EP层合板Ⅱ型层间断裂韧性和冲击强度的影响。结果表明:PEEK的加入有效提高CF/EP层合板的Ⅱ型层间断裂韧性和冲击强度。当PEEK含量为2%,层合板的断裂韧性和冲击强度分别达到1 253 J/m²和259 kJ/m²,与纯层合板相比分别提高61.5%和32.8%。实验分析PEEK增韧机理,为研究高附加值复合材料产品提供参考。     

PAN基高模碳纤维阳极氧化的表面处理

采用阳极氧化法对PAN基高模碳纤维进行连续表面处理,重点研究了氧化电流密度对碳纤维宏观力学性能、表面形貌、表面酸性官能团以及碳纤维增强树脂基复合材料(CFRP)层间剪切强度(ILSS)的影响。结果表明,电流密度对纤维力学性能、表面形貌影响不大;氧化后纤维表面总的酸性官能团显著提高,最大增幅达13倍左右;适当的处理条件可使CFRP的ILSS从28.4 MPa提高到80 MPa以上。