芳纶/阻燃环氧树脂复合材料的性能研究

以对位芳纶增强无卤阻燃环氧树脂预浸料为原料,采用模压成型工艺制备了芳纶/环氧复合材料层合板。对不同成型压力条件下复合材料层合板的厚度、纤维体积含量以及力学性能进行了测试,用金相显微镜对不同成型压力条件下试样横截面的微观形貌进行表征,并对层合板的阻燃性能进行了测试。结果表明,在固化温度(160℃)和固化时间(90 min)恒定的情况下,当固化压力为0.8 MPa时,层合板厚度和纤维体积含量基本不再发生变化,层间结合紧密,综合力学性能最优,成型质量最好。层合板的极限氧指数为44.57%,垂直燃烧等级可达V-0级,耐热性能、阻燃性能优异。     

混杂纤维复合材料性能研究

对碳纤维织物、玻璃纤维织物和芳纶织物的性能进行测试,采用热熔法分别制备了一种增韧中温固化环氧碳纤维织物预浸料、玻璃纤维织物预浸料和芳纶织物预浸料。预浸料以单种预浸料铺层和不同纤维织物预浸料混合铺层方式铺贴组合,通过模压法成型复合材料层合板,进行性能测试并对比。结果表明,增韧中温固化环氧树脂的不同纤维织物预浸料混合铺层成型的层压板力学性能可以根据铺层设计优化,并不损失不同纤维铺层之间的界面性能。     

浅谈碳纤维预浸料中铺放纤维非织造网布的适用性

选取了两种纤维非织造网布,分别在进口单向碳纤维预浸料和国产单向碳纤维预浸料层与层之间进行铺放,采用预浸料成型工艺制备不同性能的层合板,并通过测试层合板试样的力学性能和孔隙率,表明纤维非织造网布在碳纤维预浸料成型技术中的适用性。对比测试数据结果发现:纤维非织造网布经向纤维纤度、纬向纤维纤度、面密度选材合适时,在碳纤维预浸料层合板中表现出了优异的适用性;纤维非织造网布经向纤维纤度及纬向纤维纤度较小、面密度选择较大时,在碳纤维预浸料层合板中虽然也表现出良好的工艺适用性,但是碳纤维预浸料层合板的力学性能会降低,孔隙率会偏大。     

T700／3234层合板力学性能的研究

研究了T700／3234层合板力学性能,T700／3234层合板铺层45°／-45°／0°／90°／0°／0°／90°／0°／-45°／45°.T700／3234中温固化环氧碳纤维单向预浸料适应于热压罐成型工艺方法.测试了23℃、60℃、80℃、100％下,T700／3234层合板拉伸性能、压缩性能、弯曲性能、层间剪切强度及层合板的拉伸剪切强度,得出不同温度下层合板各项力学性能的保持率,表明：T700／3234复合材料使用温度不大于80℃.     

超薄T700/环氧树脂预浸料力学性能研究及微观结构表征

为了研究超薄碳纤维树脂基预浸料力学性能并探究其微观结构,制备了常规和超薄预浸料层合板,对其进行了基础力学性能测试并利用金相显微镜、扫描电子显微镜及原子力显微镜表征了微观结构。通过对比发现,薄层化提高了复合材料宏观拉伸性能,降低了弯曲和层间剪切性能,但是薄层化后的复合材料在抵抗基体分层裂纹方面表现出了显著的优势;同时薄层化会使纤维在树脂中分布均匀,层间孔隙减少,纤维与树脂的界面厚度减小。     

国产高强高模PAN基碳纤维预浸料的制备及性能研究

以国产CNI QM55高强高模聚丙烯腈(PAN)基碳纤维、氰酸酯树脂为原料,利用热熔法制备高强高模PAN基碳纤维预浸料,通过纤维面密度、树脂含量、挥发分含量等来评价预浸料的物理性能,结合单向板的微观形貌与层间剪切强度分析单向板的界面结合性能,并对预浸料铺制单向板的力学性能进行表征。结果表明：CNI QM55碳纤维预浸料的纤维面密度为145 g/m²,树脂质量分数为35.5%,挥发分质量分数为0.164%,预浸料的物理性能满足复合材料的性能要求;以CNI QM55碳纤维预浸料制备的单向板0°拉伸强度为2 429 MPa, 0°拉伸模量为328.4 GPa,弯曲强度为1 171 MPa,弯曲模量为280 GPa,压缩强度为783 MPa,压缩模量为257 GPa,层间剪切强度为65.2 MPa,具有较好的界面黏接性能和力学性能,可满足加工应用要求。     

中温固化环氧树脂芳纶Ⅲ纤维复合材料性能研究

对芳纶Ⅲ纤维和及其织物(F-3S175)的性能进行测试,采用热熔法制备了3233中温固化环氧树脂F-3S175芳纶布预浸料,通过热压罐法成型复合材料层合板和蜂窝夹层板,进行性能测试,与Kevlar 49纤维进行对比。结果表明,芳纶Ⅲ纤维、织物和其3233树脂复合材料性能高于Kevlar 49芳纶纤维、织物及其复合材料性能。     

DP590高强钢/碳纤维复合层板制备及拉伸性能研究

采用模压成型工艺,以DP590钢板与碳纤维预浸料成功制备高强钢/碳纤维层板,针对其微观结构和拉伸性能进行了测试,研究了钢板表面粗糙度对层板拉伸强度的影响,并结合DP590高强钢拉伸性能特点与MVF理论提出了层合板拉伸强度预测公式。研究结果表明:所制备的层合板0°碳纤维层、90°碳纤维层、树脂基体、金属基体结合致密。金属基体与碳纤维层之间由树脂填充,起到了良好的粘结作用,微观结构基本无成型不良缺陷,所制备层合板的密度相比DP590高强钢降低达24%,具备明显的减重效果。说明模压成型工艺适用于高强钢/碳纤维复合层板的制备,该类材料具备较大的轻量化潜力。采用喷丸处理提高钢板表面粗糙度可以一定程度提升层合板强度,最大增幅达68 MPa,但钢板粗糙度与层合板平均拉伸强度呈明显的非线性关系。以MVF理论为基础,分别以高强钢抗拉强度、屈服强度、复合层板断裂时高强钢应力值对复合层板强度进行预测,结果发现最高预测误差分别为38.5%、12.8%、8.1%,说明采用塑性较高的金属制备金属/纤维复合层板类结构时,应用MVF理论进行预测应充分考虑金属塑性较高对预测误差的影响。采用复合层板断裂时对应的高强钢应力值代入MVF理论公式可获得更好的拉伸强度预测精度。     

成型工艺对中温固化环氧树脂碳纤维复合材料性能影响

对3233中温固化环氧树脂黏度-温度曲线、凝胶时间-温度曲线和DSC进行了分析。采用热熔法制备了其碳布预浸料,通过热压罐法、模压法和真空袋法成型复合材料层合板,进行性能测试并对比。结果表明,3233中温固化树脂固化工艺为(125±5)℃固化90～120 min。采用热熔法制备的3233/CF3052中温固化环氧碳布预浸料具有良好工艺性能。模压成型和热压罐成型的层合板力学性能相当,略高于真空袋成型。3233树脂具有良好的韧性,夹层结构的抗滚筒剥离强度高,其预浸料可与蜂窝直接共固化。     

高模玻纤单向织物在风电叶片主梁帽中的应用对比

对四种高模玻纤分别进行了浸胶纱的拉伸性能、层合板的单层厚度及0°拉伸性能的研究,并对四种高模玻纤对工字梁刚度的影响进行了模型分析。四种高模玻纤具有相近的原纱拉伸模量,层合板在等纤维体积含量下具有相近的0°拉伸模量,但是在真空导入成型工艺中,由于单层厚度的差异导致纤维体积分数不同,从而具有不同的0°拉伸模量。在应用于同样铺层的工字梁时,单层厚度为0.78mm的高模玻纤层合板对应的工字梁刚度比单层厚度为0.83mm的高模玻纤层合板增加约6%。     

Mechanical characterization and fractography of glass fiber/polyamide (PA6) composites

The mechanical properties of the glass fiber reinforced Polyamide (PA6) composites made by prepreg tapes and commingled yarns were studied by in‐plane compression, short‐beam shear, and flexural tests. The composites were fabricated with different fiber volume contents (prepregs—47%, 55%, 60%, and commingled—48%, 48%, 49%, respectively) by using vacuum consolidation technique. To evaluate laminate quality in terms of fiber wet‐out at filament level, homogeneity of fiber/matrix distribution, and matrix/fiber bonding standard microscopic methods like optical microscopy and scanning electron microscopy (SEM) were used. Both commingled and prepreg glass fiber/PA6 composites (with V_f ∼ 48%) give mechanical properties such as compression strength (530–570 MPa), inter‐laminar shear strength (70–80 MPa), and transverse strength (80–90 MPa). By increasing small percentage in the fiber content show significant rise in compression strength, slight decrease in the ILSS and transverse strengths, whereas semipreg give very poor properties with the slight increase in fiber content. Overall comparison of mechanical properties indicates commingled glass fiber/PA6 composite shows much better performance compared with prepregs due to uniform distribution of fiber and matrix, better melt‐impregnation while processing, perfect alignment of glass fibers in the composite. This study proves again that the presence of voids and poor interface bonding between matrix/fiber leads to decrease in the mechanical properties. Fractographic characterization of post‐failure surfaces reveals information about the cause and sequence of failure. POLYM. COMPOS., 36:834–853, 2015. © 2014 Society of Plastics Engineers     

Preparation and Physico-Chemical Study of Sandwich Glass-Jute-Bisphenol-C-Formaldehyde Resin Composites

Glass-Jute-bisphenol-C-formaldehyde (Glass-Jute-BCF) sandwich composites were prepared by hand lay-up technique at 150°C under 30.4 MPa pressure for 2 h. The resin, glass and jute fiber content in the sandwich composite were 33.3, 10.4 and 56.3 wt%, respectively. 10 prepregs containing 8 inner prepregs of jute mats sandwiched between 2 outer prepregs of glass mats. Glass-Jute-BCF sandwich composite has 23 MPa tensile strength, 119 MPa flexural strength, 1.72 kV/mm electric strength and 1.25 × 10¹² ohm cm volume resistivity. Tensile strength and volume resistivity both decreased, while flexural strength and electrical strength both improved upon hybridization. Sandwich composite showed high diffusivity in water, 10% NaCl and 10% HCl solutions as compared to Glass-BCF composite. Equilibrium water absorption time is found to be 72 h in all 3 environments. Comparatively low diffusivity is observed due to silane treated glass fibers. No effect of boiling water is observed on stability of composite. Saturation time in boiling water reduced 18 times without any damage to the composite. Glass-Jute-BCF sandwich composite may be useful for low load bearing applications in construction, electrical and electronic industries as well as in harsh acidic and saline environments.     

汽车复合材料层合板准静态力学性能的试验测定

以应用于某新能源电动汽车的复合材料层合板为研究对象,利用万能试验机和静态应变测试分析系统等提出了可靠的复合材料层合板准静态拉伸和压缩力学性能试验测定方法,从而为复合材料结构在汽车轻量化中的设计和应用提供了试验依据。该层合板结构采用±45°交叉铺层方法,由2层碳纤维、1层芳纶纤维和2层玻璃纤维层叠构成。试验结果表明,该复合材料层合板在准静态拉伸时呈现沿±45°方向和层间分离挤压的断裂失效模式,这与其内部纤维铺层方向是一致的。同时,由于在复合材料板材中加入了增韧和板材失效时起连接作用的芳纶纤维和玻璃纤维铺层,该复合材料层合板的整体力学性能较常见碳纤维增强复合材料板材,其弹性模量和强度性能均有所降低。     

碳纤维布/玻纤布增强聚氨酯复合材料的研究

以聚氨酯为基体树脂,分别以碳纤维布、玻璃纤维布和这两种纤维布交替铺叠作为增强材料,采用真空辅助灌注成型工艺制备了4种复合材料.考察了纤维布的铺层结构对复合材料的弯曲、拉伸和冲击性能的影响.结果显示,复合材料的拉伸模量和弯曲模量随碳纤维含量增加而增加,冲击强度则降低.分别采用TGA、DMA和SEM对复合材料的热性能、界面...     

纤维增强CFP/PPS复合材料的制备与性能表征

以碳纤维(CF)和碳纤维粉末(CFP)为导电基体,制备出导电聚苯硫醚(PPS)复合材料.研究了复合材料的形貌、导电及力学性能.结果 表明,CFP能很好地分散在PPS复合材料内部,复合材料的表面电阻可达到103 Ω.同纯PPS复合材料相比,导电性能增加了四个数量级;一定范围内的CFP可以提高PPS复合材料的拉伸强度和冲击...     

Evaluating the mechanical performance of supercritical CO2 fabricated polymide 6,6/PMMA,fiber reinforced composites

Recent advancements in SC CO₂ mediated synthesis and material processing have led to polymer‐polymer blends and composite materials with complex morphologies, exhibiting long‐range order and orientation on multiple length‐scales from the nanometer to the centimeter scale. The material under consideration in this work is a polyamide 6,6 (nylon)/poly (methyl methacrylate) (PMMA) fiber‐reinforced composite that was fabricated in a unique SC CO₂ assisted process. The tensile and flexural properties of these unique composites are studied and the evolution of damage and energy dissipation are monitored through cyclic loading and microscopic analysis of post‐stressed composite cross sections. It is shown that this morphology leads to improved flexural modulus and increased ultimate strength with only a small decrease in tensile modulus. These composites also exhibited significant improvements in stress distribution and load transfer without the use of fiber sizing agents for fiber/matrix compatibilization.     

Characterization of Short Glass Fiber–Reinforced Castor Oil–Based Polyurethane Polystyrene Interpenetrating Networks

ABSTRACT

Chopped strand glass fiber–reinforced particle-filled castor oil–based polyurethane polystyrene composites with varying weight fractions of glass fibers were investigated for morphology, tensile strength, and absorption of various chemicals. The short glass fiber fraction was varied from 1% to 16% (by wt.) of the total composite system. The tensile strength of these composites was much higher than that of unfilled IPNs for the same concentration of polystyrene. The tensile strength of the IPN composites increases with the increase in fiber content up to a fiber percentage of 9%. After that, there is a sharp decline in tensile modulus as well as elongation at break. The chemical absorption showed an increase with increasing glass fiber content.     

Mechanical properties of pineapple leaf fiber-reinforced polyester composites

Pineapple leaf fiber (PALF) which is rich in cellulose, relatively inexpensive, and abundantly available has the potential for polymer reinforcement. The present study investigated the tensile, flexural, and impact behavior of PALF-reinforced polyester composites as a function of fiber loading, fiber length, and fiber surface modification. The tensile strength and Young's modulus of the composites were found to increase with fiber content in accordance with the rule of mixtures. The elongation at break of the composites exhibits an increase by the introduction of fiber. The mechanical properties are optimum at a fiber length of 30 mm. The flexural stiffness and flexural strength of the composites with a 30% fiber weight fraction are 2.76 GPa and 80.2 MPa, respectively. The specific flexural stiffness of the composite is about 2.3 times greater than that of neat polyester resin. The work of fracture (impact strength) of the composite with 30% fiber content was found to be 24 kJ m⁻². Significant improvement in the tensile strength was observed for composites with silane A172-treated fibers. Scanning electron microscopic studies were carried out to understand the fiber-matrix adhesion, fiber breakage, and failure topography. The PALF polyester composites possess superior mechanical properties compared to other cellulose-based natural fiber composites. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1739–1748, 1997     

Nonwoven polylactic acid and flax biocomposites

Flax fiber‐reinforced polylactic acid (PLA) biocomposites were made using a new technique incorporating an air‐laying nonwoven process. Flax and PLA fibers were blended and converted to fiber webs in the air‐laying process. Composite prepregs were then made from the fiber webs. The prepregs were finally converted to composites by compression molding. The relationship between the main process variables and the properties of the biocomposite was investigated. It was found that with increasing flax content, the mechanical properties increased. The maximum tensile strength of 80.3 MPa, flexural strength of 138.5 MPa, tensile modulus of 9.9 GPa and flexural modulus of 7.9 GPa were achieved. As the molding temperature and molding time increased, the mechanical properties decreased. The thermal and morphological properties of the biocomposites were also studied. The appropriate processing parameters for the biocomposites were established for different fiber contents. POLYM. COMPOS., 34:1611–1619, 2013. © 2013 Society of Plastics Engineers     

竹原纤维/可生物降解塑料复合材料的性能研究

通过热压成型制备了竹原纤维增强可生物降解塑料复合材料,研究了材料的力学性能、热稳定性、断裂面的微观结构等,以及复合材料的微生物降解性能。研究结果表明,复合材料的拉伸强度和弯曲强度随竹原纤维含量增加而增加,当竹原纤维质量分数为16.67%时,复合材料的拉伸强度和弯曲强度较纯可降解塑料分别增加46.9%和93.1%,但断裂伸长率和冲击强度随着竹原纤维含量增加而降低。复合材料的热稳定性比纯可降解塑料和竹原纤维更好。在土壤微生物的作用下,复合材料在20 d时间的降解率可达19.4%。