Mechanical Properties of Phenolic-Resin Composites Reinforced with CF/BF Interlayer Hybrid Fibers

Phenolic-resin composites reinforced with carbon fiber（CF） and basalt fiber（BF） interlayer hybrid fibers plain fabric were fabricated.The tensile strength,compressive strength and interlaminar shear strength of the prepared composites were studied.The results indicated that hybrid fibers reinforced composites possessed the advantages of both CF and BF.When resin content was 35% by volume fraction,the comprehensive mechanical performance of BF/CF reinforced phenolic resin composites reached the optimal values with the warp and weft direction tensile strength,compressive strength and interlayer shear strength being 252 MPa and 487 MPa,105 MPa and 129 MPa,21 MPa and 20 MPa,respectively.The scanning electron microscope（SEM） observations showed that the BF/CF hybrid fibers reinforced composites had better interfacial adhesion.

Effect of Hybridization on the Mechanical Properties of Pineapple Leaf Fiber/Kenaf Phenolic Hybrid Composites

In this study,pineapple leaf fiber(PALF),kenaf fiber(KF)and PALF/KF/phenolic(PF)composites were fabricated and their mechanical properties were investigated.The mechanical properties(tensile,flexural and impact)of the PALF/KF/PF hybrid composites were investigated and compared with PALF/KF composites.The 3P7K exhibited enhanced tensile strength(46.96 MPa)and modulus(6.84 GPa),flexural strength(84.21 MPa)and modulus(5.81 GPa),and impact strength(5.39 kJ/m2)when compared with the PALF/PF and KF/PF composites.Scanning electron microscopy(SEM)was used to observe the fracture surfaces of the tensile testing samples.The microstructure of the 7P3K hybrid composite showed good interfacial bonding and the addition of KF improved the interfacial strength.It has been concluded that the 3P7K ratio allowed obtaining materials with better mechanical properties(tensile,flexural and impact strengths)than PALF/PF and KF/PF composites.The results obtained in this study will be used for further comparative study of untreated hybrid composites with treated hybrid composites.

Durability Testing of Composite Aerospace Materials Based on a New Polymer Carbon Fiber-Reinforced Epoxy Resin

In this study,the durability of a new polymer carbonfiber-reinforced epoxy resin used to produce composite material in the aerospacefield is investigated through analysis of the corrosion phenomena occurring at the microscopic scale,and the related infrared spectra and thermal properties.It is found that light and heat can con-tribute to the aging process.In particular,the longitudinal tensile strength displays a non-monotonic trend,i.e.,itfirst increases and then decreases over time.By contrast,the longitudinal compressive and inter-laminar shear strengths do not show significant changes.It is also shown that the inter-laminar shear strength of carbonfiber/epoxy resin composites with inter-laminar hybrid structure is better than that of pure carbonfiber materials.The related resistance to corrosion can be improved by more than 41%.

Effect of volume fraction of ramie cloth on physical and mechanical properties of ramie cloth/UP resin composite

Ramie cloth/UP resin composite was formed at 0.2 MPa and cured at room temperature for 24 h and treated at 80℃for 2 h. The physical and mechanical properties of the composites with different volume fractions of ramie cloth were studied. The results show that, with the increase of the volume fraction of the ramie cloth, densities of the composites become greater and greater, though all lower than the theoretical values, the linear shrinkage during the formation decreases from 1.20% of the original UP resin to 0.18% of the composite with 30% of ramie cloth in volume, all the composites also absorb more water than UP resin casting, greater volume fraction of the fiber, more water will be absorbed, but the increase in water absorption becomes smaller and smaller with time. As regards some mechanical properties, the tensile strength, flexural strength, flexural modulus and impact strength are all improved when more ramie fiber is added. Compared with those of pure UP resin casting, the mechanical properties are increased by 93.93%, 76.20%, 190.18% and 227.26% respectively when the volume fraction of the ramie cloth in the composite is 30%. The differential scanning calorimetry results show that only one peak will appear for the sample without or with less ramie fiber while two peaks will appear when more ramie cloth is added.

A Review of Recent Advances in Hybrid Natural Fiber Reinforced Polymer Composites

Natural fiber reinforced polymer composites(NFRCs)have demonstrated great potential for many different applications in various industries due to their advantages compared to synthetic fiber-reinforced composites,such as low environmental impact and low cost.However,one of the drawbacks is that the NFRCs present relatively low mechanical properties and the absorption of humidity due to the hydrophilic characteristic of the natural fibre.One method to increase their performance is hybridization.Therefore,understanding the properties and potential of using multiple reinforcement’s materials to develop hybrid composites is of great interest.This paper provides an overview of the recent advances in hybrid natural fiber reinforced polymer composites.First,the main factors that affect the performance of hybrid fiber-reinforced composites were briefly discussed.The effect of hybridization on the mechanical and thermal properties of hybrid composites reinforced with several types of natural fibers(i.e.,sisal,jute,curauá,ramie,banana,etc.)or natural fibers combined with synthetic fibers is pre-sented.Finally,the water absorption behaviour of hybrid fiber-reinforced composites is also discussed.It was con-cluded that the main challenges that need to be addressed in order to increase the use of natural-natural or natural-synthetic hybrid composites in industry are the poor adhesion between natural fibers and matrix,thermal stability and moisture absorption of natural fibers.Some of these challenges were addressed by recent develop-ment in fibers treatment and modification,and product innovation(hybridization).

Evaluation of Sawdust and Rice Husks as Fillers for Phenolic Resin Based Wood-Polymer Composites

We produced Wood-Polymer Composites (WPCs) with phenolic resin (PR) filled with saw dust (SD) and rice husks (RH) in a PR:fillerratio of 60:40 wt.%. RH and SD were grinded and sieved into particles μm. The aim of this research work was to evaluate sawdust and rice husks as fillers for sustainable phenolic resin based WPCs. Therefore, we investigated the thermal stability of PR/RH and PR/SD WPCs then we studied and compared the tensile, flexural properties of PR/SD and PR/RH WPCs samples, as well as their dimensional stability after water absorption test. Furthermore, through ultraviolet light exposure, we evaluated the effects of photo-oxidation on the water stability and mechanical properties of PR/RH and PR/SD WPCs samples compared to unexposed ones. PR filled with SD presented better mechanical properties compared to PR/RH WPCs samples. However, PR/RH WPCs showed good mechanical properties, and better thermal resistance and better water repulsion capabilities compared to PR/SD WPCs samples. Although, long time UV exposure ended up lowering considerably the mechanical properties and water resistance of PR/SD and PR/RH WPCs, both RH and SD offer great added value as fillers for PR based WPCs;SD having better interactions with PR matrix compared to RH.

Hybrid Bio-based Composites from Waste Chicken Feather and Betel Nut Fiber: A Study on the Mechanical and Thermal Properties

The present work is an attempt to develop bio-based hybrid composites by incorporating Betel nut Fiber(BF)and Chicken feather Fiber(CF)at different ratios in modified soybean oil matrix by compression molding technique.The ratio of the fiber and resin was taken as 30:70.Epoxidised soybean oil(ESO)was modified by using methacrylic acid and methacrylic anhydride.The ratio of CF and BF was varied from 2:1 to 1:2 respectively.The influence of hybrid fibers and fiber ratio on various properties of the composites was investigated.The obtained results showed that composites prepared with 1:1 ratio of CF and BF exhibited highest tensile strength compared to the other composites prepared by using different ratios of CF and BF.The surface morphology of the composites was studied by Scanning Electron Microscopy(SEM),where surface roughness was found to be decreased after incorporation of hybrid fibers.Thermogravimetric analysis was carried out to study the behaviour of the composites at high temperature,where thermal stability was found to enhance for hybrid composites compared to the composites prepared with single fibers.Also properties like water vapour uptake capacity and volumetric swelling were measured and found to be decreased for the hybrid composites.An overall improvement in properties was observed for composites having 1:1 ratio of CF:BF.Hence,it is concluded that 1:1 weight ratio of CF and BF is the optimum mixing ratio to enhance the various properties of the hybrid composites.

Performance Evaluation of Calcium Alkali-treated Oil Palm/Pineapple Fibre/Bio-phenolic Composites

The utilisation of oil palm fibre(OPF)and pineapple leaf fibres(PALF)as reinforcement materials for bio-phenolic composites is growing especially in automotive lightweight applications.The major aim of this current study is to investigate the influence of alkali(Ca(OH)_(2)) treatment on pure and hybrid composites.The effects of enhancements in chemical interactions were evaluated by the Fourier-Transform Infrared Spectrometer(FTIR).Dynamic Mechanical Analysis(DMA)and Thermogravimetric Analysis(TGA)performance of untreated reinforcements(OPF and PALF)and treated(OPF/OPF)composites at varying temperature and noted sufficient interfacial bonding contributing towards the improvements in thermal stability.From DMA results,the storage modulus improved with treated composites while the damping factor was reduced.Furthermore,the treated hybrid composites exhibited significant improvements in thermal stability compared to untreated fibre composites.The results indicated that alkali calcium hydroxide(Ca(OH2(:T)incorporation in hybrid composites(OPF/PALF)results in increased tensile strength and modulus among all composites.Similarly,the alkali-treated(Ca(OH)_(2))-treated pure composite(T/50%PALF),and hybrid composites(T/1OPF.1PALF)exhibited better flexural strength as compared with other composites.In contrast,the T/50%PALF showed higher flexural stress of 78.2 MPa,while the flexural modulus was recorded at 6503 MPa.It can be proposed from the findings of this study that the alkali treatment(5%Ca(OH)_(2))can be utilised to improve the strength and efficiency of agriculture biomass to be used as reinforcements in composites.Additionally,the hybridisation of bio-fibre composites has the potential as a novel variety of biodegradable and sustainable composites appropriate for several industrial and engineering applications.

PBO纤维增强复合泡沫绝缘材料的制备及性能研究

为了提高支柱复合绝缘子芯体用复合泡沫材料的强度,使用聚对苯撑苯并二噁唑(PBO)纤维增强复合泡沫材料,通过研究不同含量PBO纤维对复合泡沫材料热学、力学和绝缘性能的影响,确定适合于内绝缘应用的纤维含量。结果表明:PBO纤维的加入赋予了复合泡沫材料抵抗冲击破坏的能力,当PBO纤维质量分数为0.4%时,复合泡沫材料落锤冲击试验吸收的能量达到最高;PBO纤维的加入能够降低材料的热膨胀率,提升热稳定性,降低潜在的热应力风险,且对复合泡沫材料的内绝缘性能影响不大。

多功能性聚苯并噁嗪树脂及其纳米复合材料研究进展

简要介绍了聚苯并噁嗪树脂(PBZ)作为新型酚醛型热固性树脂的性能及其应用,并指出了目前存在的不足。对PBZ树脂的合成方法及优缺点进行了概述,并对其开环机理及功能化改性进行了补充。在此基础上,回顾了PBZ复合材料目前国内外共聚、共混两大体系的研究现状,分析了在不同结构和方法下PBZ的性能。针对PBZ基纳米复合材料,分为碳基纳米材料和非碳基纳米材料两类,并对其作了较为详尽的综述。最后对PBZ树脂及其复合材料的发展前景与应用前景作了展望。

建筑节能用玻纤复合材料的制备及其性能研究

选择以环氧树脂E51为基体,玻璃纤维为增强相,间苯二胺为固化剂,玻璃纤维掺杂量为环氧树脂和固化剂总质量的0,5%,10%,15%和20%,制备出了玻纤复合材料。研究了不同玻璃纤维掺杂量对玻纤复合材料微观形貌、孔径分布、力学性能及导热性能的影响。结果表明,掺入适量的玻璃纤维后提高了环氧树脂各部分与纤维之间的结合强度,从而改善了玻纤复合材料的致密性,减小了平均孔径、孔体积和孔隙。当玻璃纤维的掺杂量为15%(质量分数)时,玻纤复合材料的孔洞和缺陷数量最少,结合强度和致密性最佳,孔体积最小为0.95 cm^(3)/g,平均孔径最小为26.3 nm,孔隙率最低为0.93%。随着玻璃纤维掺杂量的增加,玻纤复合材料的抗拉强度、断裂延伸率和抗折强度均先增高后降低,导热系数先降低后增大。当玻璃纤维的掺杂量为15%(质量分数)时,抗拉强度、断裂延伸率和抗折强度均达到最大值,分别为45.10 MPa,1.61%和39.60 MPa;导热系数最低为0.021 W/(m·K),保温性能最佳,在建筑节能材料的开发与应用方面具有广阔的前景。

2.5D石英纤维增强纳米孔酚醛树脂基复合材料的力学和传热性能

本文以2.5D石英纤维预制体为增强体,以纳米孔酚醛树脂为基体,通过溶胶-凝胶、常压干燥工艺制备了具有优异力学性能和低热导率的2.5D石英纤维/纳米孔酚醛树脂基复合材料,并基于力学和热导率的测试表征和有限元分析,系统研究了复合材料的微观结构、传热性能和力学性能。结果表明:酚醛树脂在微观上呈现纳米孔三维网状结构,有效地实现了较低密度(1.35 g/cm^(3))和低热导率(0.18 W·m^(-1)·K^(-1)),提升了材料的隔热性能;同时由于2.5D编织结构中经纱弯曲程度较高而纬纱分布较直,复合材料的力学性能和断裂行为展现出各向异性的特征。进一步建立了以实际材料结构、力学和热学参数为基础的有限元分析模型,预测了纤维体积分数、基体参数和纤维参数对复合材料不同方向热导率和弹性模量的影响规律。

建筑用聚酯玻纤复合材料的制备与性能分析

选择不饱和聚酯树脂为基体材料,以玻璃纤维为增强相,采用模压成型工艺制备了不同玻璃纤维掺杂量(0,5%,10%,15%和20%(质量分数))的聚酯玻纤复合材料,分析了玻璃纤维含量对复合材料的微观形貌、热稳定性、拉伸性能和弯曲性能的影响。结果表明,聚酯玻纤复合材料中玻璃纤维和不饱和聚酯主要以物理作用为主,适量的玻璃纤维掺杂后能与聚酯基材紧密结合,分布具有方向性。随着玻璃纤维掺杂量的增大,聚酯玻纤复合材料的分解温度先增大后减小,且耐热性能提高,当玻璃纤维的掺杂量为15%(质量分数)时,复合材料的T 50%达到最大值368.47℃。力学性能测试表明,随玻璃纤维掺杂量的增大,复合材料的拉伸强度和冲击强度先增大后减小,断裂延伸率和弯曲强度持续降低,当玻璃纤维的掺杂量为15%(质量分数)时,复合材料的力学性能最优,拉伸强度最大为26.1 MPa,断裂延伸率为2.6%,冲击强度达到最大值8.1 MPa,弯曲强度为30.5 MPa。

RTM成型聚酰亚胺复合材料研究

以苯乙炔封端聚酰亚胺树脂为基体,采用高温RTM工艺复合成型了T300碳布增强聚酰亚胺层合板,复合材料的Tg达351℃(DMA),材料在300℃弯曲强度保持率达90%以上,模量保持率达85%以上,层间剪切强度保持率达60%以上。

纳米SiO_2改性BOZ/BMI/BADCy共聚物的制备及性能研究

研究了纳米SiO2含量对苯并恶嗪树脂(BOZ)/双马来酰亚胺(BMI)/双酚A型氰酸酯(BADCy)/纳米SiO2复合材料力学性能、热性能和吸水性能的影响。结果表明,当纳米SiO2质量分数为3%时,BOZ/BMI/BADCy/纳米SiO2复合材料具有较高的强度和良好的韧性,其缺口冲击强度和弯曲强度比BOZ/BMI/BADCy共聚物分别提高了11.6%和8.5%;同时,纳米SiO2质量分数为3%时BOZ/BMI/BADCy/纳米SiO2复合材料具有优异的耐热性,其初始热分解温度和最大热分解温度分别为343.2℃和430.3℃。

新型酚醛树脂MPN作为复合材料基体的评价

研究了羟甲基炔丙基改性酚醛树脂（Methylol propargyl novolac resin：MPN）作为复合材料基体的工艺性和耐热性，评价了其作为树脂基体的石英布层合板复合材料的力学性能和耐热性。结果表明：加成缩合二元固化型MPN树脂具有适用于RTM（Resin transfer moulding）、模压等多种成型方法的良好工艺性；树脂浇铸体表现出优异的耐热性，其玻璃化温度达到350℃以上；MPN树脂石英布层合板的力学性能相对普通酚醛树脂层合板有所提高，其中MPN树脂中羟甲基含量增大会导致材料力学性能降低；MPN石英布层合板的耐热性则远优于酚醛树脂层合板，前者的玻璃化温度（以DMA表征，360～380℃）远高于后者（〈280℃）。

球形二氧化硅/环氧树脂复合材料制备与性能表征

以普通角形二氧化硅为原料,采用氧-乙炔火焰法制备出球形二氧化硅。将环氧树脂(E-51)、固化剂(906)、固化促进剂(DMP-30)和球形化前后二氧化硅按照不同的比例经机械搅拌混合、超声分散和升温固化(100℃、2h和150℃、2h)后制备出二氧化硅/环氧树脂复合材料。研究对比球形化前后二氧化硅对环氧树脂浇注体系热学和力学性能的影响。结果表明:球形二氧化硅的加入,提高了环氧树脂的热稳定性,添加量30%时热分解温度达到最大值340℃,球形化后二氧化硅/环氧树脂复合材料热膨胀系数和初始黏度较球形化前明显降低,力学性能得到提高。

玻璃纤维增强硼改性酚醛树脂复合材料的性能

研究了玻璃纤维(GF)含量对玻璃纤维增强硼改性酚醛树脂(GF/BPR)复合材料力学性能、耐热性能的影响.结果表明:随着玻璃纤维含量的增加,GF/BPR复合材料的弯曲强度和压缩强度均提高,当玻璃纤维含量达到50%(质量分数,下同)时,其弯曲强度和压缩强度达到最大值;GF/BPR复合材料的冲击强度随着玻璃纤维的增加而增大,当玻璃纤维含量达到70%时,GF/BPR复合材料的冲击强度达到最大值;GF/BPR复合材料的软化变形随着玻璃纤维含量的增大而逐渐降低;当玻璃纤维含量为50%时,GF/BPR复合材料的热变形温度达到196.6℃,比纯BPR提高了51.3℃,而热膨胀系数则降低近1个数量级,为1.6×10-5℃-1.

不饱和聚酯树脂/苎麻布/碱式硫酸镁晶须复合材料的力学性能及热性能研究

研究了不饱和聚酯树脂(UP 树脂)/苎麻布/碱式硫酸镁晶须复合材料的力学性能,探讨了苎麻布、晶须加入量对复合材料力学性能及热稳定性的影响,分析了复合材料的冲击断裂形貌。研究表明:当复合材料中苎麻布的质量恒定为 UP 树脂质量的7%时,增加晶须的含量,复合材料的弯曲模量及热稳定性随之增加,弯曲强度逐渐下降,拉伸强度及冲击强度先增加而后降低,当晶须加入量为10%时,拉伸强度及冲击强度均达到最大值,分别为30.16 MPa 和6.07 kJ/m^2;当复合材料中晶须的质量恒定为 UP 树脂质量的10%时,增加复合材料中苎麻布的含量,复合材料的力学性能均随之增加,但热稳定性却下降。UP 树脂/苎麻布/晶须复合材料的断面既有晶须裸露,又有卷曲的苎麻纤维分布,但苎麻布对冲击强度的贡献更突出。

PHET/PF原位复合材料力学、动态力学和热性能研究

自行合成了端羟基的热致性聚酯液晶(PHET),采用原位复合的方法制备了热致性聚酯液晶(PHET)/酚醛树脂(PF)原位复合材料,研究了PHET的用量对PHET/PF原位复合材料的冲击强度、弯曲强度、动态力学性能、热性能等的影响。结果表明,PHET的加入可以提高PHET/PF原位复合材料的力学性能、动态力学性能和热性能,当PHET质量分数为7.5%时,原位复合材料的冲击强度、弯曲强度和玻璃化转变温度(Tg)分别提高了44.69%、44.68%和22.9℃。在200℃时,PHET/PF共混物中液晶丝状织态结构明显且分布连续。