共查询到20条相似文献，搜索用时 250 毫秒
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随着不可再生资源急剧消耗,绿色、低碳和循环经济体系构建已成为各行各业可持续发展的重中之重。竹产业是我国一大特色产业,在“碳达峰、碳中和”双碳战略以及“禁塑令”政策的大力推行下,竹纤维作为一种新型天然绿色纤维成为当前研究热点之一。竹纤维具有强度高、密度小、弹性好、耐磨、透气、可再生、可降解等特点,相比玻璃纤维和碳纤维易降解,且降解碳排量少,可作为复合材料增强相代替部分塑料,有着巨大经济潜力。但目前竹纤维制备均伴随着大量污染,失去了自身环保优势,且制备的竹纤维存在木质素残留多、纤维长度短、并丝毛羽多、粗细不均匀等问题,制约竹纤维在纺织和复合材料领域高附加值的应用。本研究基于大量文献报道,重点总结近年来竹纤维环保制备方法的研究概况,对比各种方法制备竹纤维的基本性能,分析各种方法的优缺点和关键技术难点,并对竹纤维制备进行展望。新型环保制备技术创新和高效自动化设备升级,是实现原料、设备和工艺一体化发展,提升竹纤维自身性能,降低制品成本,拓展竹纤维高附加值产品开发的重要发展方向。 相似文献
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竹纤维的制备、结构与性能研究进展 总被引：1，自引：0，他引：1
分别介绍了竹原纤维与竹浆纤维的制备方法,论述了竹纤维的结构形态与主要性能,提出了竹纤维研究中存在的问题,并对今后的研究方向进行了的探讨. 相似文献
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以竹纤维和聚乳酸(PLA)为原料,乙二醇、甘油、聚乙二醇400、尿素、甲酰胺和柠檬酸酯为增塑剂,通过熔融共混法制备了竹纤维/PLA可降解复合材料。探讨了一元增塑、二元复合增塑和三元复合增塑对竹纤维/PLA复合材料拉伸强度、抗弯强度、断裂伸长率和耐水性能的影响。试验结果表明,不同增塑剂对竹纤维/PLA复合材料的增塑效果不同,甘油增塑复合材料的拉伸强度和抗弯强度最大,甲酰胺增塑复合材料的断裂伸长率最大,柠檬酸酯增塑复合材料的耐水性能最优。二元复合增塑具有协同增塑效果,甘油/柠檬酸脂复合增塑竹纤维/PLA复合材料的拉伸强度和抗弯强度最大,乙二醇/甲酰胺复合增塑竹纤维/PLA复合材料的断裂伸长率最大,乙二醇/柠檬酸酯复合增塑竹纤维/PLA复合材料的耐水性能最优。三元复合增塑在获得较好相容性的同时,复合材料的韧性明显提高,甘油/柠檬酸酯/乙二醇、甘油/柠檬酸脂/甲酰胺复合增塑竹纤维/PLA复合材料不仅具有较高的强度,且断裂伸长率和耐水性能均较好,优于一元和二元增塑效果。 相似文献
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为研究中温固化环氧树脂固化体系改善常见高温固化环氧树脂的应用受限及不足,笔者以双氰胺(DCD)为环氧树脂固化剂,2-甲基咪唑(2-MI)为促进剂,通过溶剂交换和熔融共混相结合的方法制备了环氧树脂/2-甲基咪唑/双氰胺的改性环氧树脂复合材料。试验通过添加不同质量分数的2-MI分析环氧树脂性能的变化。采用冲击、拉伸性能测试、热重分析(TGA)和扫描电镜(SEM)方法研究了复合材料的力学性能、热稳定性及断面形貌。结果表明,2-MI的加入可有效改善体系的拉伸和冲击强度,且加入质量分数为0.4%~0.5%时最佳,断裂伸长率显著提升,起到明显增强和增韧作用。扫描电镜显微镜分析结果表明,加入固化剂的环氧树脂复合材料界面黏合性更好,但2-MI的加入量对体系热稳定性无明显影响。 相似文献
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C. A. Fuentes M. van Hellemont L. Q. N. Tran C. Dupont-Gillain A. W. Van Vuure I. Verpoest 《世界竹藤通讯》2012,10(5):47
本研究利用系统地实验性结果描述了竹纤维的动态润湿性能,并通过润湿分子动力学理论进行了分析。结果表明,竹纤维的表面能够对润湿分析表现良好可控性。通过这种方式,利用不同的热塑性塑料对竹纤维的表面自由能的进行附着力的研究,可以得到界面相互作用的有价值的信息。为了提高竹纤维的相容性,本研究利用壳聚糖进行涂膜,并且使用吊片法(Wilhelmy technique)通过接触角测量对这种处理方法的效果进行了评估,利用酸碱理论计算表面自由能的分量。这些值是用来推算粘附力的理论上产生的效果。对于各种热塑性基质(聚偏氟乙烯,聚丙烯和马来酸酐接枝聚丙烯)进行润湿行为后的特征,本研究利用原子力显微镜观察其表面微形貌,用X射线光单子能谱(XPS)确定其表面的化学成分。此外,本研究还制备了单向竹纤维复合材料,以通过3点弯曲试验实现对因粘附引起的纤维改性效果的直接测量。 相似文献
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超声辅助提取对竹纤维结构和机械性能的影响 总被引：1，自引：1，他引：0
文章以超声波辅助提取竹纤维,研究超声波处理以及超声波处理方式（前超声和后超声）对低试剂量条件下提取竹纤维结构和热性能的影响。结果表明：超声波处理应用于低试剂量竹纤维提取,可降低竹纤维胶质含量,改善竹纤维细度和细度均匀性。用后超声辅助提取竹纤维,竹纤维胶质含量可降低13.2%,纤维直径由489±247 μm降至224±52 μm,平均直径降低率达54.2%。超声辅助提取对竹纤维机械性能有一定程度的影响,对竹纤维拉伸强度略有降低,拉伸模量下降明显,断裂伸长率略有提高,机械强度均匀性增加;后超声辅助提取较前超声辅助提取对竹纤维的机械性能降低程度小。经提取工艺,竹纤维结晶度增加,但超声辅助提取竹纤维结晶度又略有下降,未超声竹纤维结晶度为56.50%,后超声竹纤维结晶度为55.89%,前超声竹纤维结晶度为56.25%;傅里叶红外光谱分析表明,竹纤维化学结构变化主要由纤维提取工艺引起,超声处理对纤维结构影响不明显;通过电镜观察,经纤维提取工艺,原竹材结构中被胶质包覆的单纤维形态暴露,单丝状明显,超声辅助提取增加了纤维表面粗糙度,后超声辅助提取单丝分散性增强;总体上,超声辅助提取可促进低试剂量条件下的长竹纤维提取,对纤维细度有明显改善效果,但对纤维结构和机械性能影响不大。 相似文献
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The aim of this study is to investigate the properties of CaCO3 in situ treated bamboo pulp fiber (BPF) composites that have been filled with epoxy resin by means of vacuum-assisted resin infusion (VARI). Un-treated and treated BPF were processed at a pressure of 0.24 MPa into BPF preforms. VARI was used to infuse epoxy resin through the BPF preforms to make BPF composites. The flexural properties, impact property, and thermal properties of the BPF composites were analyzed. CaCO3 with the loading of 30 wt% affects the performance of the composites. The flexural strength did not decrease and modulus of the treated BPF composites increased by 9.38%, while the impact strength decreased by 50.98%, compared to the control sample. Dynamic mechanical analysis revealed the maximum elastic moduli of the treated specimens increased by 1.19 times in the temperature range of ?20 to 120 °C. The thermal decomposition temperature of the composites was influenced by the effect of the crystal field and size effect of CaCO3. 相似文献
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铁路轨枕复合材料组分特性及对整体性能影响的分析 总被引：1，自引：0，他引：1
分析主要增强材料木质剩余物、辅助增强材料玻璃纤维、基体材料酚醛树脂及填充材料工业灰渣等单独组分的特性及对轨枕复合材料整体特性的影响。结果表明,作为铁路轨枕复合材料的4种主要组分,各自优点突出,特性相互适应,将对复合材料整体产生积极、良好的复合效果。 相似文献
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Liva Pupure Janis Varna Roberts Joffe Fredrik Berthold Arttu Miettinen 《Wood material science & engineering》2020,15(2):76-86
ABSTRACTComposites formed from wood fibers and man-made cellulosic fibers in PLA (polylactic acid) matrix, manufactured using sheet forming technique and hot pressing, are studied. The composites have very low density (due to high porosity) and rather good elastic modulus and tensile strength. As expected, these properties for the four types of wood fiber composites studied here improve with increasing weight fraction of fibers, even if porosity is also increasing. On the contrary, for man-made cellulosic fiber composites with circular fiber cross-section, the increasing fiber weight fraction (accompanied by increasing void content) has detrimental effect on stiffness and strength. The differences in behavior are discussed attributing them to fiber/ fiber interaction in wood fiber composites which does not happen in man-made fiber composites, and by rather weak fiber/matrix interface for man-made fibers leading to macro-crack formation in large porosity regions. 相似文献
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织物增强聚合物(TRP)因其具有优异的机械性能而被广泛应用于汽车、建筑等领域。传统TRP材料通常以玻璃纤维、碳纤维作为增强体,由于成本高及不可降解等问题限制了发展和应用。本研究采用可生物降解的天然黄麻纤维为增强体,以乙烯酯为基体树脂,采用模压工艺制备双层黄麻织物增强乙烯酯树脂复合材料。考察经纱和纬纱的取向对复合材料密度、孔隙率及力学性能的影响。通过调整黄麻织物的纱线角度(0°,30°,45°,60°和90°),研究经纬纱角度对复合材料性能的影响,采用的模压成型工艺是80℃、7 MPa条件下压制2.5 h。为了考察模压温度的影响,将纱线角度为60°的试样在40℃的低温条件下(其余条件不变)压制成型。结果表明:与纯乙烯酯相比,黄麻纤维具有一定的增强作用,复合材料的弯曲强度和冲击强度分别提高24.77%和39.83%,拉伸性能降低30.52%。扫描电子显微镜结果显示,复合材料力学强度的提高与纱线间的孔隙分布有关。在研究范围内,经纬纱定向对复合材料的冲击强度影响比较显著。低温(40℃)条件下,制备的定向角为60°时的黄麻纤维增强乙烯基酯复合材料的各项力学性能达到最佳。 相似文献
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Chemical components are the main factors affecting the mechanical properties of wood fibers. Lignin is one of the main components of wood cell walls and has a critical effect on the mechanical properties of paper pulp and wood fiber based composites. In this study, we carried out tensile tests on single mature latewood tracheids of Chinese fir (Cunninghamia lanciolata (Lamb.) Hook.), using three different delignified treatment methods to obtain different amounts of lignin. We applied single fiber tests to study the effect of the amount of lignin on mechanical tensile properties of single wood fibers at the cellular level. The results show that in their dry state, the modulus of elasticity of single fibers decreased with the reduction in the amount of lignin; even their absolute values were not high. The amount of lignin affects the tensile strength and elongation of single fibers considerably. Tensile strength and elongation of single fibers increase with a reduction in the amount of lignin. 相似文献
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采用加速老化试验方法对竹复合管材的湿热老化性能及老化机理进行研究,探究不同湿热老化历时下竹复合管材拉伸、压缩和弯曲性能的变化。结果表明,在交变湿热应力作用下,竹复合管材拉伸强度、压缩强度、压缩弹性模量、弯曲强度和弯曲弹性模量随湿热老化时间延长呈幂指数降低,拉伸劣化大于弯曲,弯曲劣化大于压缩,模量劣化大于强度;湿热老化28次后,竹复合管材拉伸强度、压缩强度、压缩弹性模量、弯曲强度和弯曲弹性模量分别降低34.11%、25.64%、26.39%、26.14%和27.83%。交变湿热应力使结构层树脂和竹纤维均发生湿胀,结构层树脂湿胀率小于竹纤维,不均匀的湿胀使结构层树脂受拉、竹纤维受压,结构层树脂竹纤维界面产生剪切力,树脂开裂、脱落,纤维树脂界面形成孔洞和微裂纹降低有效应力传递,当剪切力大于界面粘结力时,界面损伤模式主要表现为脱粘以及剪切分层。 相似文献
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Oliver Mertens Kim C. Krause Matthias Weber Andreas Krause 《Wood material science & engineering》2020,15(2):114-122
ABSTRACTThermomechanical wood fibers, as usually used for medium density fiberboard or cardboard production, feature promising characteristics, like a high aspect ratio, for the utilization in thermoplastic composites. The present study investigates the influence of fiber loading and fiber geometry on the mechanical properties of wood-polypropylene composites in order to confirm the results that were found in a previously published literature review. Composites were compounded at fiber contents from 20 to 60 wt.%, using a co-rotating twin-screw extruder and subsequently injection molded to test specimens. Field emission scanning electron microscopy was carried out to evaluate the fracture morphology of the composites. Fiber length was evaluated using an applying a dynamic image analysis system. Compounding reduced fiber lengths up to 97%. The mechanical properties decreased with increasing fiber content for composites without a coupling agent. Strength properties peaking at a fiber content of 50?wt.% for composites containing MAPP. Tensile strength and flexural strength reached 48.1 and 76.4 MPa, respectively. However, it was found that the processing of these fibers into conventional compounding equipment is still challenging. 相似文献
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Rashmi Kumari Hirokazu Ito Masahiro Takatani Miho Uchiyama Tadashi Okamoto 《Journal of Wood Science》2007,53(6):470-480
Although wood/cellulose-plastic composites (WPC) of low wood/cellulose content have been more accepted worldwide and are promoted
as low-maintenance, high-durability building products, composites containing high wood/cellulose content are not yet developed
on an industrial scale. In this study, flow properties, mechanical properties, and water absorption properties of the compounds
of cellulose microfiber/polypropylene (PP) and maleic anhydride-grafted polypropylene (MAPP) were investigated to understand
effects of the high cellulose content and the dimensions of the cellulose microfiber. The molding processes studied included
compression, injection, and extrusion. It was found that fluidity is not only dependent on resin content but also on the dimension
of the filler; fluidity of the compound declined with increased fiber length with the same resin content. Dispersion of the
composite was monitored by charge-coupled device (CCD) microscope. Increasing the plastic content in the cellulose-plastic
formulation improved the strength of mold in addition to the bond development between resin and filler, and the tangle of
fibers. The processing mode affected the physicomechanical properties of the cellulosic plastic. Compression-molded samples
exhibited the lowest modulus of rupture (MOR) and modulus of elasticity (MOE) and the highest water absorption, while samples
that were injection-molded exhibited the highest MOR (70 MPa) and MOE (7 GPa) and low water absorption (2%). 相似文献