苎麻落麻的表面处理及其复合材料的性能研究

采用甲基丙烯酸甲酯、丙烯腈接枝,硅烷偶联剂(A-151)偶联,聚氯乙烯(PVC)包覆等方法对苎麻落麻纤维进行表面处理;测试了处理前后落麻纤维的吸水率、单丝强度及其与环氧树脂(EP)、酚醛树脂(PF)和不饱和聚酯(UP)等的接触角;观察了偶联和包覆后落麻纤维的表面状况;选取偶联和包覆后的落麻纤维制备了UP/落麻毡和PP/落麻纤维复合材料,测试了其拉伸和弯曲性能并观察了处理前后复合材料的拉伸断面形貌。结果表明,接枝、偶联和包覆不仅降低了落麻纤维的吸水速率。而且也降低了平衡吸水量;接枝对落麻纤维单丝强度影响最大,偶联次之,包覆最小;接枝、偶联和包覆均能大幅度改善落麻纤维与EP、PF和UP的浸润性;偶联和包覆后的落麻纤维表面都比处理前粗糙;偶联使UP/落麻毡复合材料的拉伸强度、拉伸弹性模量提高了21％,弯曲强度提高了34％,弯曲弹性模量提高了40％,包覆使PP/落麻纤维复合材料的拉伸、弯曲强度提高了20％左右。     

协同改性处理对剑麻增强HDPE复合材料力学性能的影响

植物纤维和树脂的界面相容性差一直制约着天然纤维复合材料的发展和应用。分别对剑麻纤维(SF)进行了碱-偶联协同处理和碱-接枝协同处理,并利用双螺杆挤出机制备了SF/高密度聚乙烯(HDPE)复合材料。观察了剑麻纤维表面以及复合材料断面的微观形貌,表征了改性前后纤维基团的变化,研究了协同改性处理对剑麻纤维及其复合材料力学性能的影响。结果表明,碱-偶联协同处理的改性效果更好,剑麻纤维与HDPE的相容性得到明显改善,复合材料最大拉伸强度和弯曲强度相对于未改性纤维复合材料分别提高18.64%和20.25%。     

改性木纤维/PVC复合材料界面及性能的研究

比较了硅烷偶联剂处理、氢氧化钠溶液浸泡与硅烷偶联剂双重处理,接枝改性等3种木纤维表面处理方法对木纤维/PVC复合材料界面及性能的影响,通过扫描电镜照片发现接枝改性木纤维在PVC基体中分散更均匀,与PVC界面相容性好.接枝改性木纤维/PVC复合材料的拉伸强度、冲击强度、断裂伸长率等力学性能有明显提高.最后分析了木纤维接枝改性处理时引发剂用量对复合材料力学性能的影响.     

汽车内饰用PP/黄麻纤维复合材料力学性能

采用转矩流变仪混合造粒,通过注射成型方法制备了聚丙烯(PP)/黄麻纤维复合材料,研究了对纤维表面进行处理的NaOH浓度、纤维含量和相容剂的含量对PP/黄麻纤维复合材料力学性能的影响,采用扫描电镜对纤维表面及复合材料的断面形貌进行分析。结果表明:黄麻纤维经过碱处理后PP/黄麻纤维复合材料的力学性能优于纤维未处理的复合材料的力学性能,随着NaOH浓度的提高,PP/黄麻纤维复合材料的拉伸强度和冲击强度增加,在NaOH浓度为16%时,其拉伸强度和冲击强度最佳;其弯曲强度随着NaOH浓度的提高先增加而后下降,在8%浓度时,弯曲强度最大。随着纤维含量的提高,PP/黄麻纤维复合材料的拉伸强度和弯曲强度先增加后下降,在纤维含量达到20%时,PP/黄麻纤维合材料的拉伸强度和弯曲强度达到最大。随着纤维含量的提高,PP/黄麻纤维复合材料的冲击强度降低。相容剂的加入使得PP/黄麻纤维复合材料的拉伸强度和弯曲强度明显增加。     

杨木纤维表面改性及其HDPE复合材料性能研究

利用过氧化物作为引发剂,加入马来酸酐偶联把聚乙烯蜡接枝到杨木纤维表面上。接枝前后木纤维的红外光谱和色散自由能的显著变化证实了接枝反应的发生,并通过一系列实验计算了反应的接枝率;随着反应温度的提高,接枝率呈上升趋势,在170％以上变化趋势变缓。与未改性的木纤维相比,改性后木纤维填充HDPE复合材料的力学性能有较大提高,其拉伸、弯曲、冲击强度可分别提高34．9％,29．2％和8．8％,但随着聚乙烯蜡接枝量的增大,材料力学性能又有所下降。扫描电镜照片显示改性木纤维在基体中分散更均匀,界面结合良好。     

尼龙6改性研究

采用经化学改性的芳纶纤维增强尼龙6,并通过红外光谱和电镜分析其界面层,结果表明芳纶纤维经异氰酸酯化及封端稳定处理后,其表面所接技的不稳定基团-NCO转化成稳定的-NHCO-,封端结果较为明显;改性后纤维表面附有接枝物,从而使表面粗糙程度大大增加。用挤出和注塑的方法加工了PA6／Kevlar纤维（KF）复合材料,研究了它的拉伸、弯曲和冲击性能破坏形态。力学性能测试表明了改性尼龙6复合材料的拉伸和弯曲强度得到了改善,但冲击性能略为下降。     

离子聚合物改性木塑复合材料的研究

研究了钠离子聚合物(Surlyn 8940)对杨木粉/高密度聚乙烯(HDPE)木塑复合材料的增容和增韧改性效果,并与马来酸酐接枝聚乙烯(MAPE)改性杨木粉/HDPE木塑复合材料相比较。通过万能力学试验机和悬臂梁冲击试验机测试了不同用量的钠离子聚合物或MAPE改性HDPE复合材料的力学性能,以及使用场发射扫描电镜观察钠离子聚合物改性HDPE复合材料的表面和断面形貌。结果表明,当木粉质量分数为40%时,添加4%钠离子聚合物的复合材料的拉伸强度(25.8 MPa)比添加4%MAPE时提高了78.6%;随着钠离子聚合物含量的增加,复合材料的弯曲弹性模量呈现出明显的降低趋势,而添加钠离子聚合物的复合材料的弯曲强度要高于添加MAPE复合材料的弯曲强度,并且发现钠离子聚合物对复合材料有突出的增韧效果,表明钠离子聚合物对于木塑复合材料是较好的增容增韧剂;SEM分析表明添加离子聚合物后,塑料基体对木粉有很好的包覆效果,没有明显的界面缝隙。     

芦苇纤维增强低密度聚乙烯复合材料力学性能研究

以芦苇纤维作增强剂,制备了低密度聚乙烯(PE-LD)/芦苇纤维复合材料,研究了芦苇纤维、马来酸酐接枝低密度聚乙烯(PE-LD-g-MAH)及硅灰石的含量对PE-LD/芦苇纤维复合材料力学性能的影响.结果表明,未加入增容剂PE-LD-g-MAH时,随芦苇纤维含量的增加,复合材料的拉伸强度和弯曲强度先略有增加而后降低,冲击强度则呈下降趋势;PE-LD-g-MAH提高了复合材料的拉伸强度和弯曲强度,当PE-LD-g-MAH质量分数为10％时,复合材料的力学性能最好;硅灰石及芦苇纤维的质量分数分别为10％和20％时,复合材料具有较好的力学性能.     

体能训练器械引入改性碳纤维复合材料的性能测试研究

采用分子沉淀法在碳纤维表面接枝碳纳米管进行改性，制备了体能训练器械用碳纤维复合材料。对比分析了未改性和接枝改性碳纤维及其复合材料的显微形貌、拉伸性能和冲击性能。结果表明，碳纤维在接枝表面改性后，表面形成了含O和含N的官能团，且随着接枝层数增多，碳纤维表面接枝CNTs逐渐增多，未发生明显团聚。改性碳纤维的单丝拉伸强度、界面剪切强度会得到不同程度提高；经过接枝改性处理后，改性碳纤维复合材料的碳纤维复合材料的冲击形成功、裂纹扩展功和总冲击功都有不同程度提高，且随着接枝改性层数的增加，改性碳纤维复合材料的碳纤维复合材料的冲击形成功、裂纹扩展功和总冲击功都逐渐增大。接枝改性处理有助于提升碳纤维单丝和复合材料的力学性能。     

接枝物含量对高层建筑用GF/PP复合材料性能的影响

为了提高高层建筑用材料的力学性能,采用熔融共混的方法,在玻璃纤维(GF)增强聚丙烯(PP)复合材料中加入马来酸酐接枝PP(PP-g-MAH)与马来酸酐接枝聚烯烃(POE-g-MAH),分析接枝物含量对复合材料拉伸性能、弯曲性能以及冲击性能的影响。研究表明：当POE-g-MAH或PP-g-MAH的加入量为4 g时,复合材料的流动性明显改善,达到了最大熔体流动速率。当基体中接枝物含量上升后,复合材料的拉伸强度表现为先增大后减小的变化趋势,弯曲强度以及弯曲弹性模量都出现了先增大后减小的变化趋势,并在含有4 g接枝物时达到最大。当复合材料中接枝物含量增大后,含有POE-g-MAH接枝物的复合材料的冲击强度迅速增大。扫描电镜显示,加入接枝物后GF表面上存在明显附着物,GF和PP基体之间形成了良好相容性。     

Effect of coupling agents on the mechanical properties of mica/epoxy and glass fiber/mica/epoxy composites

The effect of coupling agents, two silane and one zirconate, on the mechanical properties of mica/epoxy and glass fiber/mica/epoxy composites has been investigated. The results showed that tensile modulus and flexural strength and modulus values were improved by the surface treatment of the coupling agents. The property retention was also found to be better in the case of coupling agent-treated mica/epoxy samples after boiling in water for 2h. In the case of glass fiber/mica/epoxy composites, the flexural modulus and interlaminar shear strength values improved with increase in mica content, but the effect of coupling agents was not pronounced.     

周期性孪晶结构碳化硅纳米线改性环氧树脂的性能

通过超声分散和模具浇注成型法制备了周期性孪晶结构碳化硅(SiC)纳米线改性环氧树脂,探讨了SiC纳米线的周期性孪晶结构及含量对环氧树脂复合材料力学性能的影响。结果表明,周期性孪晶结构SiC纳米线的加入明显改善了环氧树脂基体的力学性能,孪晶结构有助于提高SiC纳米线与基体树脂之间的相互结合程度。随着孪晶SiC纳米线含量的增加,复合材料的拉伸性能和弯曲性能都呈现出先增加后减小的趋势。当SiC纳米线的含量为2%时,复合材料的拉伸强度、拉伸弹性模量、断裂伸长率、弯曲强度和弯曲弹性模量均达到最大值,相比于纯环氧树脂分别提高了90.6%,37.8%,38.3%,53.4%和24.5%。当SiC纳米线含量为3%时,弯曲应变达到最大值(6.72%),相比于环氧树脂提高了32.0%。     

环氧树脂/短切碳纤维复合材料性能研究

制备出了短切碳纤维增强TDE-85环氧树脂复合材料,研究了碳纤维的含量对复合材料力学性能和耐热性能的影响。结果表明,碳纤维的加入有利于复合材料力学性能和耐热性能的提高,并在碳纤维含量为0.25%时,复合材料的拉伸强度、冲击韧性、弯曲强度和弯曲模量达到最大,分别提高了29.33%、25.31%、30.28%和68.93%。此外,对复合材料的弯曲断裂面进行了微观形貌分析,结果表明一定量的碳纤维可以较好地分散在树脂基体中,同时,碳纤维原丝和树脂基体的界面结合比较弱,主要依赖于两相之间的物理嵌合。     

碳纤维-环氧树脂复合材料的制备及力学性能表征

用低温等离子体技术对碳纤维针织物进行处理,将E-44环氧树脂基体与碳纤维织物进行复合,在温度为40℃、模压压力1.5 MPa条件下,采用模压成型法,加热1 h,保温2 h后,制备出碳纤维复合材料。测试了复合材料的拉伸性能、弯曲性能及压缩性能,得出经过等离子体处理后,碳纤维复合材料的纵向拉伸强度比改性处理前提高了31.12%,横向拉伸强度提高了40.61%;纵向弯曲强度提高了26.42%,横向弯曲强度提高了23.41%;纵向抗压强度提高了40.41%,横向抗压强度提高了29.74%。等离子体处理有利于碳纤维与树脂的结合,使得制备出的碳纤维复合材料的力学性能得到提高。     

Effect of Coupling Agent Concentration,Fiber Content,and Size on Mechanical Properties of Wood/HDPE Composites

In this study, the influence of coupling agent concentration (0 and 3 wt%), wood fiber content (50, 60, 70, and 80 wt%), and size (40–60, 80–100, and 160–180 mesh) on the mechanical properties of wood/high-density-polyethylene (HDPE) composites (WPCs) was investigated. WPC samples were prepared with poplar wood-flour, HDPE, and polyethylene maleic anhydride copolymer (MAPE) as coupling agent. It was found that the tensile properties and the flexural properties of the composites were improved by the addition of 3 wt% MAPE, and the improved interfacial adhesion was well confirmed by SEM micrographs. It was also observed that the best mechanical properties of wood/HDPE composites can be reached with larger particle size in the range studied, while too-small particle size was adverse for the mechanical properties of wood/HDPE composites. Moreover, the tensile modulus, tensile strength, and flexural strength of WPCs decreased with the increase in fiber content from 50 to 80 wt%; the flexural modulus of WPCs increased with the increase in fiber content from 50 to 70 wt% and then decreased as the fiber content reached 80 wt%. The variances in property performance are helpful for the end-user to choose an appropriate coupling agent (MAPE) concentration, wood fiber content, and particle size based on performance needs and cost considerations.     

Banana fiber reinforced low-density polyethylene composites: effect of chemical treatment and compatibilizer addition

In this study, an attempt has been made to utilize banana fiber (a natural fiber from agricultural waste) as reinforcement for low-density polyethylene (LDPE) to develop environmental friendly composite materials. LDPE/banana fiber composites were fabricated at different fiber loadings (10, 15, 20, 25, and 30 wt %) using compression molding technique. The composite with the composition of 25 wt % banana fiber was observed to be optimum on the basis of biodegradability and mechanical properties. Further, the effect of banana fiber surface treatment (alkali and acrylic acid) on the mechanical properties, morphology and water absorption behavior of the LDPE/banana fiber composites in the absence and presence of compatibilizer (maleic anhydride grafted LDPE, MA-g-LDPE) was comparatively studied. The alkali and acrylic acid treatment of the banana fibers led to enhanced mechanical properties and water resistance property of the composites, and these properties got further improved by the addition of the compatibilizer. The addition of compatibilizer to the acrylic acid treated banana fiber composites showed the most effective improvement in the flexural and impact strength and also, exhibited a reduction in the water absorption capacity. However, the tensile strength of the compatibilized composites with treated fibers resulted in slightly lower values than those with untreated fibers, because of the degradation of fibers by chemical attack as was evidenced by scanning electron microscopy (SEM) micrographs. SEM studies carried out on the tensile fractured surface of the specimens showed improved fiber-matrix interaction on the addition of compatibilizer.     

Investigation into the morphological and mechanical properties of date palm fiber-reinforced epoxy structural composites

This study aims to examine the morphology and mechanical properties (tensile, flexural, and compressive) of epoxy composites reinforced with epoxy date palm leaves (EDPL), epoxy date palm branch (EDPB), and epoxy/hardener date palm core shell (EDPC) fibers (particle size <1 μm depend on the date palm fibers). A three-step technique was used to obtain the composites. The EDPL composites showed a maximum tensile strength of 3.45 MPa, while the EDPB composites showed maximum compressive and flexural rigidity of 9.46 and 5.55 MPa, respectively, owing to the good compatibility of fiber-matrix bonding. In this work, epoxy composites reinforced with date palm fibers (DPF) leaves, branches, and core shell were recycled using a cost-effective and easily reproducible three-step technique. EDPC fibers fabricated with 64.65% weight carbon fibers content demonstrated improved tensile strengths and stiffness properties. The three samples of palm date composites revealed mechanical properties that could be used to trial these fibers for manufacturing purposes, and to exploit their extraordinary mechanical properties shown in current results.     

Improvement of Tensile and Flexural Properties in Epoxy/Clay Nanocomposites Reinforced with Weave Glass Fiber Reel

The tensile strength, tensile modulus, flexural strength and flexural modulus properties were investigated on epoxy/clay nanocomposites to assess the influence of nanoclay. Mechanical properties were significantly increased due to an increase in clay content up to 5 wt%, and decreased with a further increase in clay content. Optimal improvement of properties was observed with increased clay content up to 5 wt%. Duo properties of the glass fiber were improved by clay addition due to the improved interface between the glass fiber and epoxy. SEM analysis was conducted on different fractured surfaces to study the mechanical behavior.     

PA66/PP/晶须硅复合材料的制备与性能

通过双螺杆挤出机采用熔融共混的方法制备了尼龙(PA)66/聚丙烯(PP)/晶须硅复合材料.研究了偶联剂的种类以及晶须硅的用量对复合材料体系力学性能、微观形态和热性能的影响.结果表明,采用硅烷偶联剂KH560处理的晶须硅具有较好的分散性.晶须硅能够显著提高PA66/PP合金的拉伸和弯曲强度,对复合材料的韧性也有一定的改善...