RFI用环氧树脂膜的制备与应用研究

对用于RFI工艺的环氧树脂体系进行了研究,得到了满足RFI工艺要求的树脂体系及其成膜工艺参数,测试了所制得树脂膜的力学性能及存储性能,将制备出的树脂膜用于RFI工艺制备复合材料,并对复合材料的性能进行了考察。结果表明,制备出的树脂膜可用于RFI工艺制备复合材料构件,制得的复合材料构件力学性能优良。     

RFI工艺用双马来酰亚胺树脂膜

以热塑性聚醚砜树脂（PES）和聚酰亚胺树脂（PI）改性4508树脂，制得了适用于树脂膜熔渗（RFI）工艺的高性能树脂基体膜。该树脂膜室温性质稳定，发粘点高，任意弯曲不脆裂。其固化树脂的力学性能、耐热性和耐湿热性能优良，所制得的玻璃布复合材料综合性能优异。     

复合材料RFI成形用树脂膜的成膜工艺性研究

针对先进复合材料树脂膜渗透成形技术(RFI)中的树脂膜,分析了其成形的基本过程,在测定树脂体系的基本粘度-温度关系基础上,采用树脂膜/离型纸的拉伸剪切实验方法测定了树脂膜的拉伸剪切强度,研究了树脂膜在不同温度及速度下的剪切载荷-位移关系及内聚破坏及界面破坏的转变温度范围.结果显示,破坏形式的转化是决定剪切强度-温度依赖性的关键.确定了实验树脂体系的成膜工艺区间的下限.     

RFI工艺中有关树脂流动监测的研究

渗透率测定是树脂膜熔渗(RFI)工艺在复合材料设计和优化中最关键的技术.基于光导纤维视觉技术,通过纤维视觉传感器测量渗透率,能够在光强度下降的情况下探测出树脂的前进情况,这将易于我们在实际生产中在第一时间内准确地监测树脂的流动.     

树脂膜熔渗(RFI)工艺用环氧树脂/DDS体系的研究

树脂膜熔渗(Resin Film Infusion,RFI)工艺以其低成本,适合制造大型、复杂型面、带加强筋的结构件等优点受到越来越多的关注.本文对适合RFI工艺要求用树脂膜的制备及性能进行了研究.实验证明在室温下,体系配方为:双酚F型环氧树脂(BPFEP):DDS:PES=95:34.3:5时树脂的成膜性和韧性非常好.DSC方法和凝胶时间确定熔渗温度为120℃,固化工艺为150℃/2h 180℃/2h.采用RFI方法制备了GF/EP和CF/EP复合材料层合板,并对力学性能和Tg(DMA方法)进行了测试.前者层间剪切强度、弯曲强度分别达到52.1MPa和432MPa,树脂含量达到39.6%,Tg为166·1℃.后者的层间剪切强度、弯曲强度分别为66.1MPa和862MPa,树脂含量达到30.7%,Tg为164.0℃.     

RFI工艺用环氧树脂膜的制备及其化学流变特性

为研制低成本树脂膜熔渗(RFI)工艺用环氧树脂膜 , 以环氧树脂 E51、高温潜伏性固化剂三氟化硼单乙胺和乙二醇为原料 , 采用正交设计方法对配方进行优化 , 并通过控制预聚反应程度的方法进行合成实验。对所研制树脂膜的化学流变特性进行测试研究 , 结果表明 , 树脂膜在130℃工作温度下 , 最低黏度达360 mPa· s , 小于1000 mPa· s的低黏度时间达 32 min , 凝胶时间为 48 min , 并且室温不粘手 , 可任意弯曲 , 适用于RFI工艺。通过不同升温速率的DSC扫描 , 分析了预聚原液和树脂膜的反应活化能 , 发现树脂膜反应活化能比预聚原液高 , 而且树脂膜的反应活化能随着固化度增加而增加。以双 Arrhenius公式为理论基础建立了树脂膜黏度和凝胶时间的预测函数 , 实验结果表明二者均具有良好的适用性。根据 RFI工艺对黏度的要求创立了熔渗力因子的表达方程 , 并通过该方程确定了理论最佳熔渗温度为128. 4 ℃。      

新型树脂传递模塑技术

概述了传统树脂传递模塑(RTM)及在其基础上发展起来的新型RTM工艺,包括真空辅助树脂传递模塑(VARTM)、Seemann复合材料树脂浸渍模塑成型工艺(SCRIMP)和树脂膜渗透成型工艺(RFI)的成型原理、优点,并指出目前存在的缺点及解决方法.     

复合材料RFI成形的树脂膜揭取性研究

采用树脂膜/离型纸的T型剥离实验方法来表征RFI树脂膜操作过程中的揭取特性,实验研究了几种基本RFI树脂膜的T形剥离载荷-位移关系在不同加载速度及不同实验温度下的表现形式.结果显示内聚破坏与界面破坏情况下载荷位移曲线有明显不同的形式.提高温度有利于出现内聚破坏,而提高实验速度则易于出现界面破坏.进一步从实验数据总结出树脂膜揭取的工艺范围应当在出现界面破坏的温度范围内.     

树脂膜熔渗工艺充模过程的模拟与分析

树脂膜熔渗工艺(RFI)是一种新型的复合材料成型工艺.为了更深入了解树脂膜熔渗工艺过程中充模阶段的控制参数对制品质量的影响,避免制品出现空斑、充模不完全等问题,针对该工艺过程中树脂在复杂形状预制件中的流动行为进行了分析,在达西定律基础上建立了二维等温流动控制方程,利用有限元/控制体方法建立了数值分析模型,编制了FORTRAN程序进行模拟运算,并讨论了流动过程中施加的压力对充模时间的影响.由计算实例可见,所编制程序能够很好地预测树脂膜熔渗工艺过程中充模时间、各个时刻树脂的流动前沿位置及模腔中的压力分布.     

航空级树脂基复合材料的低成本制造技术

在综述大量相关文献、会议报告的基础上,概要介绍了航空级树脂基复合材料的几种主要低成本制造技术,如自动铺带技术、自动铺丝技术、低温固化预浸料技术、电子束固化、液体成型技术结合纤维编织及缝编技术和树脂膜渗透成型技术(RFI),列举了空客公司最新飞机A380使用RFI工艺制造后压力舱隔板隔框的工艺过程.     

Development and Characterization of the Midrib of Coconut Palm Leaf Reinforced Polyester Composite

In this paper, midrib of coconut palm leaves (MCL) was investigated for the purpose of development of natural fiber reinforced polymer matrix composites. A new natural fiber composite as MCL/polyester is developed by the hand lay-up method, and the material and mechanical properties of the fiber, matrix and composite materials were evaluated. The effect of fiber content on the tensile, flexural, impact, compressive strength and heat distortion temperature (HDT) was investigated. It was found that the MCL fiber had the maximum tensile strength, tensile modulus flexural strength, flexural modulus and Izod impact strength of 177.5MPa, 14.85GPa, 316.04MPa and 23.54GPa, 8.23KJ/m² respectively. Reinforcement of MCL enhanced the mechanical properties of pure polyester, including that of tensile strength (by 26%), tensile modulus (by 356%), flexural strength (by 41.81%), flexural modulus (by 169%) and Izod impact strength (by 23 times), but the compressive strength was adversely affected. HDT decreased due to fiber loading, but increased with weight fraction of fiber content. Moreover, the experimental results were compared with theoretical model (Rule of mixture) and other natural fiber /polyester composites.     

PEK-C膜层间增韧碳纤维/环氧树脂复合材料的力学性能

为探究热塑性酚酞基聚醚酮（Polyaryletherketone with Cardo,PEK-C）树脂薄膜及膜厚对层间增韧碳纤维/环氧树脂复合材料力学性能的影响,利用浸渍提拉法制备了三种不同厚度（分别约为1 μm、10 μm、30 μm）的PEK-C膜,通过热压成型制备了层间增韧碳纤维/环氧树脂复合材料层合板,对其进行了Ⅰ型层间断裂韧性、冲击后压缩强度、层间剪切及弯曲性能测试,并利用SEM观察微观形貌及AFM扫描微观相图。结果表明:不同PEK-C膜厚增韧碳纤维/环氧树脂复合材料的Ⅰ型层间断裂韧性、冲击后压缩强度及层间剪切强度有不同程度提高,Ⅰ型层间断裂韧性及层间剪切强度以膜厚为10 μm最佳,分别增大了157.17%和17.57%,冲击后压缩强度以膜厚为30 μm最佳,达到了186.67 MPa,这是由于PEK-C与环氧树脂在热压固化过程中形成了双相结构,改善了材料韧性;但弯曲性能持续下降,强度及模量由未增韧的1 551 MPa、106 GPa分别降至30 μm时的965 MPa、79 GPa,这是由于PEK-C树脂扩散进入环氧树脂中,降低了纤维体积分数及材料刚度。      

含炔基酚醛树脂改性PSA及碳纤维布/PSA-EPAN复合材料性能

合成了乙炔基苯基偶氮酚醛树脂（EPAN）,通过溶液共混的方法用其对含硅芳炔树脂（PSA）进行改性,研究了PSA-EPAN树脂的热性能,并制备了PSA-EPAN的碳布预浸料,经热模压制备碳纤维布（T300CF）增强PSA-EPAN复合材料,对其力学性能进行了研究。结果表明：EPAN均匀分布于PSA树脂中,EPAN共混改性PSA树脂的固化温度提高,混入质量分数为7%的EPAN,N₂中固化PSA-EPAN树脂在800℃残留率超过90%,其玻璃化转变温度高于500℃,PSA-EPAN共混树脂浇铸体的弯曲性能高于PSA树脂,达40.7 MPa,提高了95.5%;PSA树脂经T300CF/PSA-EPAN复合材料力学性能显著提高,弯曲强度达到了423.5 MPa,提高了74%,层间剪切强度（ILSS）提高至29.53 MPa,增加了65%。     

The effects of Clay on fire performance and thermal mechanical properties of woven glass fibre reinforced polyamide 6 nanocomposites

The effects of small amount of organically modified Clay (Clay) in polyamide 6 (PA6) on fire performance and thermal mechanical properties of Clay/PA6/woven glass fibres (GF) laminates are investigated by cone calorimeter test, dynamic mechanical thermal analysis (DMTA), and heat distort temperature (HDT) measurement. The mechanical properties, such as tensile and flexural properties of Clay/PA6 composites and Clay/PA6/GF laminates were also measured. Up to 3 wt.% Clay in a Clay/PA6/GF laminate with fibre volume fraction of 30 vol.% delayed the ignition time and peak heat release rate (PHRR) time by 55% and 118%, respectively, even though the value of the PHRR or the HDT was not significantly affected. 2 wt.% Clay increased flexural modulus and strength of the Clay/PA6/GF laminate by 10% and 16%, respectively, but more Clay did not increase the mechanical properties accordingly. Small amount of Clay does not affect glass fibre dominated properties, such as HDT, but do affect matrix dominated properties, and significantly affect the fire performance in terms of delaying ignition time and PHRR time. Optimization of laminate making process could benefit from additions of more Clay, therefore further improve fire performance and enhance mechanical properties.     

单向炭布叠层C/C复合材料的热压法制备及其性能

以经表面处理的石墨、单向炭布、和沥青粉为原料,通过热压烧结制备炭布叠层C/C复合材料.考察了炭布含量对材料密度、孔隙率、弯曲强度以及摩擦磨损的影响,采用MM200摩擦磨损试验机进行了环-块摩擦磨损实验,并借助SEM表征了材料的弯曲断口和磨痕形貌.结果表明:当炭布质量分数为50％时,C/C复合材料的综合性能最好,抗弯强度为112.2MPa,密度为1.72 g/cm3,摩擦系数为0.28,磨损率为3.68×10-13 m3·N-1·m-1.弯曲实验中材料呈“假塑性”方式破坏,断口出现大量纤维的拔出.石墨相含量的增加有利于形成较好的摩擦膜,降低磨损率,保持摩擦系数稳定.     

Fabrication and testing of natural fibre composites: Vakka, sisal, bamboo and banana

A study has been carried out to investigate the tensile, flexural and dielectric properties of composites made by reinforcing vakka as a new natural fibre into a polyester resin matrix. The fibres extracted by retting and manual processes have been used to fabricate the composites. These composites are tested for tensile, flexural and dielectric properties and compared with those of established composites like sisal, bamboo and banana made under the same laboratory conditions. The composites are fabricated up to a maximum volume fraction of fibre of 0.37 in the case of tensile testing, and 0.39 for flexural and dielectric testing. It has been observed that the tensile properties increase with respect to volume fraction of fibre for vakka fibre composite and are also more than those of sisal and banana composites and comparable to those of bamboo composites. The flexural strength of vakka fibre composite is more than that of banana composite and is closer to sisal fibre composite with respect to the volume fraction of fibre, where as the flexural modulus is much higher than those of banana and sisal fibre composites and also very much closer to bamboo fibre composites. The dielectric strength of vakka fibre composite increases with increase in volume fraction of fibre in the composite unlike the case of sisal, bamboo and banana composites. The dielectric strength being a unique feature of vakka fibre composite, can be suggested for electrical insulation applications.     

The potential of harakeke fibre as reinforcement in polymer matrix composites including modelling of long harakeke fibre composite strength

Mechanical properties of aligned long harakeke fibre reinforced epoxy with different fibre contents were evaluated. Addition of fibre was found to enhance tensile properties of epoxy; tensile strength and Young’s modulus increased with increasing content of harakeke fibre up to 223 MPa at a fibre content of 55 wt% and 17 GPa at a fibre content of 63 wt%, respectively. The flexural strength and flexural modulus increased to a maximum of 223 MPa and 14 GPa, respectively, as the fibre content increased up to 49 wt% with no further increase with increased fibre content. The Rule of Mixtures based model for estimating tensile strength of aligned long fibre composites was also developed assuming composite failure occurred as a consequence of the fracture of the lowest failure strain fibres taking account porosity of composites. The model was shown to have good accuracy for predicting the strength of aligned long natural fibre composites.     

Mechanical properties of natural fibre reinforced polyester composites: Jowar,sisal and bamboo

In this paper, the experiments of tensile and flexural tests were carried out on composites made by reinforcing jowar as a new natural fibre into polyester resin matrix. The samples were prepared up to a maximum volume fraction of approximately 0.40 from the fibres extracted by retting and manual process, and compared with established composites like sisal and bamboo developed under similar laboratory conditions. Jowar fibre has a tensile strength of 302 MPa, modulus of 6.99 GPa and an effective density of 922 kg/m³. It was observed that the tensile strength of jowar fibre composite is almost equal to that of bamboo composite, 1.89 times to that of sisal composite and the tensile modulus is 11% and 45% greater than those of bamboo and sisal composites, respectively at 0.40 volume fraction of fibre. The flexural strength of jowar composite is 4%, 35% and the flexural modulus is 1.12 times, 2.16 times greater than those of bamboo and sisal composites, respectively. The results of this study indicate that using jowar fibres as reinforcement in polyester matrix could successfully develop a composite material in terms of high strength and rigidity for light weight applications compared to conventional sisal and bamboo composites.     

碳纳米管/碳纤维/环氧树脂复合材料研究

制备了碳纳米管(CNTs)/碳纤维(CF)/环氧树脂(EP)三元复合材料。研究了CNTs含量对复合材料层间剪切强度、弯曲强度和弯曲模量的影响,并采用场发射扫描电镜分析了CNTs在基体树脂中的分散情况。结果表明:复合材料性能的变化源自于CNTs在基体树脂中的分散状态。当CNTs含量为0.2%(wt,下同)时,复合材料剪切强度和弯曲强度达到最大值,分别为99.2MPa和1811.4MPa,但其弯曲模量下降了8.7GPa。当CNTs添加量达到1%时,其弯曲模量达到135.9GPa,较未加入CNTs时提高了11.1%,层间剪切强度和弯曲强度分别降低了5.5MPa和359.5MPa。     

Evaluation of mechanical and thermal properties of banana–flax based natural fibre composite

Hybrid materials of any kind are the keynote for today’s demands. This paper deals with one of such hybrid composite made of natural fibres namely, banana and flax fibres. The structural build-up is such that one layer of banana fibre is sandwiched between two layers of flax fibres by hand layup method with a volume fraction of 40% using Epoxy resin and HY951 hardener. Glass fibre reinforcement polymer (GFRP) is used for lamination on both sides. This lamination also increases the overall mechanical properties along with better surface properties. The properties of this hybrid composite are determined by testing its tensile, impact, and flexural loads using a Universal testing machine. Thermal properties are analysed and hybrid composites of flax and banana with GFRP have better thermal stability and flame resistance over flax, banana with GFRP single fibre hybrid composites. Morphological analysis is done using Scanning Electron Microscope (SEM). The result of test shows that hybrid composite has far better properties than single fibre glass reinforced composite under impact and flexural loads. However it is found that the hybrid composite have better strength as compared to single fibre composites.