Thermo-Physical Potential of Recycled Banana Fibers for Improving the Thermal and Mechanical Properties of Biosourced Gypsum-Based Materials

The development of bio-sourced materials is essential to ensuring sustainable construction;it is considered a locomotive of the green economy.Furthermore,it is an abundant material in our country,to which very little attention is being given.This work aims to valorize the waste of the trunks of banana trees to be used in construction.Firstly,the physicochemical properties of the fiber,such as the percentage of crystallization and its morphology,have been determined by X-ray diffraction tests and scanning electron microscopy to confirm the potential and the impact of the mode of drying on the quality of the banana fibers,with the purpose to promote the use of this material in construction.Secondly,the results obtained with the gypsum matrix allowed us to note a preponderant improvement in the composite’s thermal properties thanks to the variation of the banana fiber additive.Thirdly,the impact of the nature of the banana fiber distribution(either fiber mixed in matrix or fiber series model)on the flexural and compressive strengths of the composites was studied.The results obtained indicate that the insulation gain reaches up to 40%.It depends on the volume fraction and type of distribution of the banana fibers.However,the thermal inertia of the composites developed,represented by thermal diffusivity and thermal effusivity,was studied.Results indicate a gain of 40%and 25%,respectively,in terms of thermal diffusivity and thermal effusivity of the developed composites compared to plaster alone.Concerning the mechanical properties,the flexural strength depends on the percentage of the volume fraction of banana fibers used,and it can reach 20%more than the flexural strength of plaster;nevertheless,there is a significant loss in terms of the compressive strength of the studied composites.The results obtained are confirmed by the microstructure of the fiber banana.In fact,the morphology of the banana fibers was improved by the drying process.It reduces the amorphous area and improves the cellulosic crystalline surfaces,which assures good adhesion between the fiber and the matrix plaster.Finally,the dimensionless coefficient analysis was done to judge the optimal proportion of the banana fiber additive and to recommend its use even on false ceilings or walls.

Effects of Processing Parameters on Mechanical Properties and Structure of Banana Fiber-Reinforced Composites

The mechanical properties of unidirectional natural fiber-reinforced composites are generally affected by several processing parameters during compression molding.This study investigates the effects of processing temperature,time,and pressure on the tensile and flexural properties of acrylonitrile butadiene styrene reinforced by banana fibers.X-ray CT imaging was employed to find the relationship between the mechanical properties and structure of the processed composite.Besides,the water absorption of composites was observed and the way in which the mechanical properties evolved after water absorption was analyzed.The tensile and flexural properties of the unidirectional banana fiber-reinforced composite were found to be inversely proportional to the porosity.In addition,high-pressure compression molding might result in cracks and floating fibers that would significantly reduce its mechanical properties.The composite with the highest strength,smallest porosity and lowest water absorption was optimally prepared at T=170℃,t=20 min,and P=100 kg cm^-2.

Properties and Chemical Treatment of Banana Fiber

Comparing to some other fibers,the mechanical andsome physical properties of banana fiber,constituent ofbanana fiber have been studied in this paper,mean-while,for improving some characteristics of banana fi-ber,the chemical treatments were used to modify the fi-ber.The results show that the coarse and brittle bananafiber,will be difficult to process in traditional spinningsystem.

Effect of Surface Treatment and Fiber Orientation on the Tensile and Morphological Properties of Banana Stem Fiber Reinforced Natural Rubber Composite

A mixture of NaOH and Na2SO3 was used in modification of banana stem fibers (BSF). Unidirectional BSF reinforced natural rubber (NR) lamina composites were made using compression moulding method. The results of the tensile loading in 0°, 45° and 90° to the fiber directions of the composite with fiber mass fraction of 30% were studied. Surface modification of the BSF with a mixture of 4% NaOH and 2% Na2SO3 increased the tensile strength and elastic modulus of the composite to 4.03 MPa and 147.34 MPa respectively from 3.12 MPa and 84.30 MPa of the untreated. Variation in properties due to fiber orintations was observed indicating a higher value of properties in the 0° fiber orientation than in 45° and 90° directions. The result of scanning electron microscope (SEM) micrographs of the surfaces of the fibers indicted an improvement in bonding of the fiber bundles prior to lamination with natural rubber as a result of surface treatment which resulted in its higher tensile strength.

Analysis of the Adsorption of Toxic Chromium (VI) by Untreated and Chitosan Treated Banana and Areca Fiber

This paper work involves bunch experiments to investigate the effect of contact time, pH, and adsorbent dose on the extent of adsorption by bio-composites. Adsorption capacity of Chromium (VI) onto chitosan coated with banana and areca fiber was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH and adsorbent dose. The chitosan and fibers (banana and areca) were then cross-linked with glutaraldehyde to remove chromium [Cr (VI)] from water via static adsorption. It was found that optimum chromium absorption capacity of chitosan was assessed at pH of 2.5 to 4.5 and contact time of 30 to 180 minutes for raw banana and areca fiber and for chitosan treated banana & areca fiber. Though optimum adsorption of chromium of chitosan was measured 34.17 ppm (85.42%) from a 100 ml solution containing 40 parts per million (ppm) of Cr (VI) at 120 minutes, pH of 3.0 and 120 milligram (mg) adsorbent dose size, use of composite will be more favorable in the point of environmental concern as well as low cost because chitosan preparation is comparatively costly then banana and areca fiber. On the other hand, untreated banana and areca fiber optimum adsorption of chromium measured 3.65 ppm (9.1%) at 180 min and, pH of 4.5 and 140 mg adsorbent dose size and 3.76 ppm (9.4%) at 180 min, pH of 4.5 and 160 mg adsorbent dose size respectively. In case of chitosan treated banana fiber, it was observed that adsorption was increased from 17.664 to 30.057 (75.14%). On the other hand, for areca fiber with chitosan, it was observed that adsorption was increased from 21.664 to 30.156 (75.39%) ppm. The Langmuir and Freundlich adsorption models were used for the mathematical description of the adsorption of chromium ion onto composites and it was found that the Langmuir adsorption isotherm was more fitted models which mean that a monolayer adsorption surface was created. After analyzing from IBM SPSS 25 software, we got the standard deviation value of adsorbed Cr by raw chitosan, untreated banana and areca of pH test results were 9.399, 1.072, 0.728 ppm, time test results were 2.163, 0.859, 0.896 ppm and adsorbent dose test results were 6.588, 0.966, 1.211 ppm correspondingly. The standard deviation results of pH, time and amount of treated banana fiber test results were 1.831, 2.693 and 5.469 ppm congruently. On the other hand, the standard deviation results of pH, time and amount of treated areca fiber test results were 3.293, 2.673 and 4.152 ppm individually. Fourier transform infrared (FT-IR) spectroscopy analysis indicated that both amino and hydroxyl groups of chitosan, banana and areca fiber were engaged in the adsorption.

Analysis of Water Absorption of Different Natural Fibers

The demand for natural fibers has always been high due to their unique characteristics like strength, lightweight, availability, bio-degradability, etc. In every phase of life, from clothing to technical textiles, natural fibers are used. Water absorption of fibers is considered really important in many aspects, e.g., Sportech, Medtech, Geotech, etc. This work analyses water absorption of raw and alkali-treated cotton, arecas, pineapple leaves, and banana fibers. Fibers were scoured with different concentrations of alkali (2, 4, 6 gm/L NaOH), washed and neutralized with the dilute acetic acid solution, then dried. Later on, the fiber samples were immersed into distilled water, and water absorption percentages of the fibers were determined every 10 minutes within 1 hour in total. It appeared that at untreated conditions, the areca fiber has the highest water absorption capacity compared to the other fibers. Alkali-treated cotton shows the highest water absorption, and areca fibers show approximately 60% water absorption of cotton.

香蕉茎秆纤维/抗菌纤维混纺纱的制备及其性能

为促进天然香蕉茎秆纤维在纺织服装领域的应用,采用半精纺纺纱工艺,以香蕉茎秆纤维(BF)、优可丝安泰贝抗菌纤维(ATB)和稀土抑菌再生纤维素纤维(XT)为原料,制备了混纺比为50/50、65/35、70/30、85/15的8种BF/抗菌纤维混纺纱和1种BF纯纺纱,表征了纱线的线密度和捻度,探究了混纺比例与纱线力学性能、质量指标、抗菌性能的关系。结果表明,9种纱线实测的线密度和捻度与设计值存在偏差,但其偏差在允差范围内;ATB和XT的加入提高了BF纯纺纱的力学性能与抗菌性能,改善了BF纯纺纱的条干均匀度、毛羽指数、棉结、粗节、细节等质量指标,且香蕉/抗菌纤维混纺纱强度高、毛羽少、手感柔软,适宜开发各类机织和针织面料。

香蕉茎秆纤维提取工艺优化及其表征

为了对农业废弃物香蕉茎秆进行综合利用,采用化学法脱胶工艺提取香蕉茎秆纤维。在单因素试验基础上,采用响应曲面法,以NaOH质量浓度、碱煮时间、碱煮温度为影响因素,以香蕉茎秆纤维的拉伸强度为响应值建立二次回归方程,通过响应面分析得到其优化组合。结果表明:碱煮时间对香蕉茎秆纤维拉伸强度的影响最大,其次为NaOH质量浓度,最后为碱煮温度。当NaOH质量浓度8.76 g/L,碱煮时间3.98 h,碱煮温度80.72℃,料液比1∶20(g∶mL)时,香蕉茎秆纤维的脱胶率为82.4%,含纤维素67.69%,拉伸强度为433.93 MPa。傅里叶红外结果显示较佳工艺制备的香蕉茎秆纤维去除了大量半纤维素和木质素。扫描电镜图显示香蕉茎秆纤维的断裂截面呈现脆性-塑性复合型断裂形式。

NaOH提取香蕉皮纤维对水中Pb^(2+)的吸附特性及机理研究

为探讨生物质纤维吸附材料对水中Pb^(2+)的吸附特性,以香蕉皮为原料,采用NaOH提取纤维吸附水中的Pb^(2+)。研究结果表明,在实验条件范围内,香蕉皮纤维对Pb^(2+)的理论饱和吸附量可达130.74 mg·g^(-1),远强于香蕉皮(57.44 mg·g^(-1)),其吸附平衡时间为90 min,低于香蕉皮粉末(120 min)。香蕉皮纤维对水中Pb^(2+)的吸附过程符合Langmuir等温模型和准二级动力学模型,拟合结果显示,香蕉皮粉末对Pb^(2+)的吸附亲和力较强。BET比表面积、扫描电镜、EDS能谱、傅里叶变换红外光谱表征结果表明,香蕉皮纤维较香蕉皮,其主要官能团结构未发生明显变化,但其表面形态和元素构成均发生了有利于Pb^(2+)吸附的变化。

滚扎甩碎组合式香蕉茎秆纤维提取机设计与试验

香蕉茎秆中含有丰富的植物纤维,其机械提取具有效率高、污染少等优点,是一项具有发展潜力的香蕉茎秆机械化处理技术。目前,由于香蕉茎秆粗大、含水率高等问题,机械提取香蕉茎秆纤维成熟技术较少。针对上述问题,该文研制了滚扎甩碎组合式香蕉茎秆纤维提取机,该机主要由传动系统、Ⅰ级滚扎装置、Ⅱ级滚扎装置、甩碎装置、电机等部分构成。样机性能试验表明:该机香蕉茎秆纤维提取率为89.2.%,含杂率为8.6%,生产率为206 kg/h,能耗为20.2 kW·h/100 kg,符合设计要求。与半喂入式香蕉茎秆纤维提取机相比,该机的提取率提高了8.1%,含杂率降低了6.5%,生产率提高了71.7%,能耗降低了10.6%。该研究可为香蕉茎秆纤维提机设计提供参考,对促进中国热带农业区香蕉产业发展具有重要的意义。

香蕉纤维化学脱胶工艺优化

采用化学脱胶处理香蕉纤维,对一煮和二煮工艺中的参数进行优化设计,以残胶率和残余木质素含量为指标对化学脱胶效果进行评价。结果显示:一煮工艺中,NaOH浓度、煮炼时间、Na2SO3及Na5P3O10浓度是影响脱胶效果的主要因素,优化后得出最佳工艺参数为:NaOH浓度为14 g/L、煮炼时间150 min、Na2SO3浓度3%﹑Na5P3O10浓度2.75%,残胶率为9.19%,残余木质素率为7.87%。二煮工艺中确定了NaOH浓度、H2O2浓度、处理时间为主要影响因素,最佳工艺条件为:NaOH浓度14 g/L、H2O2浓度为8%、处理时间120 min,残胶率达8.85%,残余木质素达4.68%。

阻燃香蕉纤维增强聚乳酸复合材料的制备与表征

采用乙酰柠檬酸三丁酯(ATBC)作为增塑剂增塑聚乳酸,添加改性香蕉纤维和膨胀型阻燃剂(IFR)制备阻燃香蕉纤维增强聚乳酸复合材料。研究结果表明,偶联剂处理纤维的效果最好,使复合材料的拉伸、弯曲强度分别达到57.49MPa、101.80MPa,与扫描电子显微镜(SEM)的结果一致;IFR含量为5份(以聚乳酸为100份计)时综合性能最佳,材料的极限氧指数达到了32.8%,垂直燃烧实验达到了V-0级(UL-94),材料的拉伸和弯曲强度分别为43.97 MPa和87.95MPa,效果最好。热失重研究结果表明,阻燃香蕉纤维的加入能明显提高聚乳酸的热分解温度和残炭量。

香蕉纤维的研究现状及其开发应用前景

对香蕉纤维的资源、香蕉纤维的化学组成、微细结构、物理机械性能、制取工艺以及产品开发的现状进行综述。通过与其他麻类纤维的比较,分析香蕉纤维开发中的薄弱环节,指出今后香蕉纤维开发的重点,认为香蕉纤维有极大的应用潜力和广阔的开发前景。

香蕉粘胶纤维的结构和性能研究

采用感官评定、SEM、FT-IR、铜氨溶液法、TG、DTG和DSC等分析方法对香蕉粘胶纤维的结构和性能进行表征,并与香蕉原纤维进行比较。结果表明:香蕉粘胶纤维洁白发亮,柔软细腻,有一定卷曲,表面光滑,纵向平行排列,有沟槽,截面呈不规则锯齿形;香蕉粘胶纤维具有纤维素的特征基团,1734.79、1425.75和1511.23 cm-1处吸收峰几乎消失,聚合度为325,在空气中起始热分解温度与香蕉原纤维相近,总放热量约高出975.5 J/g,在氮气中起始热分解温度比香蕉原纤维约低28℃,总吸热量约高出36.42 J/g。香蕉粘胶纤维属于棉型粘胶短纤维,湿强度为0.95 cN/dtex,干强度为2.26 cN/dtex,纯度较高,热稳定性较好,是一种良好的纺织材料。

滚筒刮拉式香蕉茎秆纤维刮取装置参数优化与试验

为解决机械法香蕉茎秆纤维提取中存在的纤维提取率较低、含杂率较高等问题,对滚筒刮拉式香蕉茎秆纤维刮取装置进行参数优化试验研究。该文制定了香蕉茎秆纤维提取率、香蕉茎秆纤维含杂率为试验指标,刮杂刀辊转速、刮刀数量、刮刀砧弧长为影响因素,通过单因素试验分析确定了各个因素对试验指标的影响规律及较优水平范围;通过三因素三水平正交试验及多元回归分析,得出刮杂刀辊转速为1 800 r/min、刮刀数量为16把、刮刀砧弧长为60 mm为试验最优参数组合,以及各因素对指标影响的主次顺序。对试验装置进行指标模型的测试试验表明:该装置生产率为207.6 kg/h,香蕉茎秆纤维提取率为93.2%,香蕉茎秆纤维含杂率为15.7%,能耗为22.1 k W·h/100 kg,符合农艺生产要求和相关行业原料标准。该试验结果有利于促进中国南方热区香蕉茎秆纤维提取装备的研制与发展。

香蕉膳食纤维的研究进展

概述香蕉膳食纤维(DF)的成分及功能,着重介绍其中的抗性淀粉,比较3种香蕉DF的含量以及贮藏过程中蕉皮DF的变化情况,简介香蕉膳食纤维的加工现状。

香蕉纤维的形态结构与性能分析

香蕉纤维是一种新型的天然纤维素纤维,通过普通光学显微镜与扫描电镜观察、红外光谱分析以及纤维强力测试,讨论与分析了香蕉纤维的形态结构与力学性能,实验结果表明,香蕉纤维的表面具有横节竖纹,截面内有裂纹存在;纤维强力测试表明,香蕉纤维具有较高的强度。

香蕉纤维的碱法脱胶工艺

研究了香蕉纤维的碱法脱胶工艺。在分析碱剂用量、亚硫酸钠用量、多聚磷酸钠用量、脱胶温度和时间等单因素影响香蕉纤维脱胶效果的基础上,通过正交实验确定香蕉纤维碱法脱胶的优化工艺:碱剂1.5 g/L,多聚磷酸钠2.5 g/L,亚硫酸钠2.0 g/L,85℃脱胶70 min。脱胶后香蕉纤维的白度为25.79%,断裂强度为21.03 cN/dtex,失重率为15.62%,满足纤维可纺性要求。

香蕉皮膳食纤维在面包中的应用研究

将香蕉皮膳食纤维加入面粉中,研究并探讨了香蕉皮膳食纤维添加量和可溶性膳食纤维(SDF)占总膳食纤维(DF)的量对面粉糊化性质、面团特性和面包烘培品质的影响,结果表明:香蕉皮膳食纤维对面粉的糊化性质有一定的影响,使面团的吸水率增加,影响了面包内部的色泽,减小了面包的比容,增大了面包的硬度;以感官评定为指标,通过正交试验得出最优化工艺参数:香蕉皮膳食纤维添加量为3%(SDF占总DF的量为15%),面包改良剂和酵母添加量分别为2%、4%,此时面包的品质最为理想。

阻燃香蕉纤维增强聚乳酸复合材料的热老化性能研究

以偶联剂处理过的香蕉纤维、聚乳酸为原料,添加膨胀型阻燃剂制备阻燃香蕉纤维增强聚乳酸复合材料。研究了复合材料老化前后的力学性能、燃烧性能、热性能、红外光谱特征和表面形貌。结果表明:老化12d后,复合材料的拉伸强度和弯曲强度分别降低了90.7%和74.4%;复合材料的燃烧性能也逐渐降低;TG、SEM、FT-IR分析结果均表明,随着热老化时间的延长,复合材料发生了部分降解。