The Role of Bamboo Nanoparticles in Kenaf Fiber Reinforced Unsaturated Polyester Composites

In this study,bamboo nanoparticles in concentration ranges from 0-5%were incorporated along with woven/nonwoven kenaf fiber mat into unsaturated polyester and the developed composites were further characterized.Bamboo chips were subjected to ball milling process for the synthesis of nanoparticles with a particle size of 52.92 nm.The effect that the incorporation of nanoparticles had on various properties of reinforced composites was further observed.Due to the high surface area of nanoparticles,incorporation of 3%of nanofillers contributed towards strong bonding and better wettability with matrix,thus resulting in excellent mechanical properties and thermal characteristics in reinforced unsaturated polyester composites.Furthermore,mechanical characteristics of reinforced composites were deteriorated by the addition of a higher percentage of nanoparticles(>3%)due to agglomeration,as confirmed by scanning electron microscopy.Moreover,ordered structural arrangement of woven kenaf textile fiber showed enhancement in interfacial adhesion and promoted superior mechanical strength in reinforced composites as compared with nonwoven composites.

Isolation and Characterization of Cellulose Nanofiber(CNF)from Kenaf(Hibiscus cannabinus)Bast through the Chemo-Mechanical Process

The present work emphasizes the isolation of cellulose nanofiber(CNF)from the kenaf(Hibiscus cannabinus)bast through a chemo-mechanical process.In order to develop high CNF yield with superior properties of CNF for improving compatibility in varied applications this method is proposed.The fiber purification involved pulping and bleaching treatments,whereas mechanical treatment was performed by grinding and high-pressure treatments.The kraft pulping as a delignification method followed by bleaching has successfully removed almost 99%lignin in the fiber with high pulp yield and delignification selectivity.The morphology of the fibers was characterized by scanning electron microscopy,which showed a smooth surface,fiber bundles,gel-shaped nanofiber,and an average size of 94.05 nm with 69%of CNF in 34–100 nm size.The chemo-mechanical process exhibited a more crystalline nature in CNF than pulp kenaf.The low zeta potential values exhibit the distribution of fibrils and colloidal suspension stability without any further agglomeration.A lower concentration of CNF is less stable exhibiting the product agglomeration.Therefore,the chemo-mechanical process for the isolation of CNF(Hibiscus cannabinus)from kenaf involves sustainable,low-cost,non-toxic,and cheap alternatives than other traditional methods.

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.

Isolation and Characterization of Cellulose Whiskers from Kenaf (<i>Hibiscus cannabinus</i>L.) Bast Fibers

Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydrochloric acid whiskers (HClW) morphology, functional groups, crystallinity, and thermal stability were characterized. The TEM images showed that the sulfuric acid and HCl whiskers have average diameters and length range of 3 nm and 100 - 500 nm, respectively. The FTIR study indicated that during the conversion process, most of the hemicellulose and almost all the lignin were removed by the NaOH and subsequent bleaching treatments. The crystallinity of HCl whiskers was found to be higher (84%) than that of sulfuric acid whiskers (72%). Thermogravimetric analysis indicated that HCl whiskers had better thermal stability than the sulfuric acid ones. In addition, a two-stage decomposition behavior was revealed by TGA in the sulfuric acid whiskers because of incorporation of the sulfate group with the cellulose crystals.

A Comprehensive Analysis of the Thermo-Chemical Properties of Sudanese Biomass for Sustainable Applications

The chemical composition and thermal properties of natural fibers are the most critical variables that determine the overall properties of the fibers and influence their processing and use in different sustainable applications,such as their conversion into bioenergy and biocomposites.Their thermal and mechanical properties can be estimated by evaluating the content of cellulose,lignin,and other extractives in the fibers.In this research work,the chemical composition and thermal properties of three fibers,namely bagasse,kenaf bast fibers,and cotton stalks,were evaluated to assess their potential utilization in producing biocomposites and bioenergy materials.The chemical composition analysis followed the Technical Association of the Pulp and Paper Industry Standards(TAPPI)methods.The total phenol content was quantified using the Folin-Ciocalteu method,while Fourier Transform Infrared Spectroscopy(FTIR)was employed to assess the light absorption by the bonds.To evaluate thermal stability and higher heating values,Thermogravimetric Analysis(TGA),Differential Scanning Calorimetry(DSC),and bomb calorimetry were performed.The chemical analysis revealed that bagasse contained 50.6%cellulose and 21.6%lignin,kenaf bast fibers had 58.5%cellulose and 10%lignin,and cotton stalks exhibited 40.3%cellulose and 21.3%lignin.The FTIR curves demonstrated a notable similarity among the fibers.The TGA analysis showed degradation temperatures of 321°C for bagasse,354°C for kenaf bast fibers,and 289°C for cotton stalks.The DSC analysis revealed glass transition temperatures of 81°C for bagasse,66.3°C for cotton stalks,and 64.5°C for kenaf bast fibers.The higher heating values were measured as 17.3,16.6 and 17.1 MJ/kg for bagasse,kenaf bast fibers,and cotton stalks,respectively.The three fibers have a high potential for biocomposites and bioenergy material manufacturing.

Effect of Natural Fiber Reinforced Polypropylene Composite Using Resin Impregnation

In this paper, we deals with mechanical performance of resin impregnation with natural fiber and fiber reinforced composites. The effect of the addition of a rein impregnation process on static strength of the injection molded composites was investigated by carrying out tensile and banding tests, followed by Scanning electron microscopy (SEM) observation of fiber surface and fracture surface of composites. The tensile strength of natural fiber and natural fiber reinforced composites with resin impregnation method increases with Polyvinyl alcohol (PVA) impregnation. In addition, Phenol resin impregnation recovers fiber tensile strength after alkali treatment. Resin impregnation causes decrease in contact surface area;however, it does not cause decrease in mechanical properties. Our results suggest that the using rein impregnation method has better effect on the mechanical properties of natural fiber reinforced Polypropylene (PP) composites.

Mechanism of Kenaf Retting Using Aerobes

The experimental results showed that the duration of microbial retting processing of kenaf fibers by using aerobic microbe was four times shorter than that by using anaerobic microbe. The residual gum percentage,breaking strength, breaking elongation and linear density of aerobic retted kenaf bundle fibers did not show significantly difference with that of anaerobic retted kenaf bundle fibers by ANOVA-Tukey's studentized test at a = 5% except for the softness. The bioenergetic principle and the calculation of the amount of ATP produced during the decomposition processing of kenaf gums were used to explain why the retting duration in the case of using aerobic microbes was much shorter than that of using anaerobic microbes.

Study On Modification Of Kenaf and Its Spinning Blended With Cotton

This paper deals with the chemical treatment of kenaf fi-ber and the spinning of the kenaf yarn blended with cot-ton. The experimental results show that after being treated by alkli, the properties of kenaf fiber have im-proved obviously, which made it possible to produce the yarn of kenaf blended with cotton. The results are very helpful for the utilization of kenaf fiber.

洋麻纤维增强全降解复合材料的制备及其弯曲模量

利用压制成型工艺制备了洋麻纤维增强全降解复合材料,分析了纤维体积分数、长度以及取向分布对材料弯曲模量的影响,并根据COX剪滞法和洋麻纤维在成型后被压缩的结构特点,探讨了一种修正COX剪滞模型对弯曲模量的预测。实验表明,随着纤维体积分数、长度和取向因子的增加,材料的弯曲模量增加。扫描电镜的观察显示洋麻纤维的横断面呈现多孔状结构,成型后受到压缩而变得致密,增加了材料的弯曲模量。预测结果表明,结合了纤维压缩率的修正模型的预测计算值与实验值取得较好的一致。

洋麻纤维的表面改性及其在聚丙烯基复合材料中的应用

采用碱处理、偶联剂处理以及碱–偶联剂复合处理对洋麻纤维进行表面改性,然后将其与聚丙烯(PP)纤维复合,采用非织造–模压工艺制备了PP/洋麻纤维复合材料。研究了上述3种表面改性方法对洋麻纤维强度及其复合材料弯曲与剪切性能的影响,并采用扫描电子显微镜(SEM)研究了洋麻纤维表面改性前后的形貌变化及其与PP基体之间的界面结合状况。结果表明,表面改性后洋麻纤维的拉伸强度均降低,但复合材料的弯曲强度及层间剪切强度均提高,表明这3种改性方法均提高了洋麻纤维与PP之间的界面结合强度;碱处理可去除纤维表面的果胶成分,使纤维束变得松散,使复合材料的弯曲强度及层间剪切强度分别较未表面改性时提高了21%和169%,但弯曲弹性模量降低了21%;偶联剂处理则使复合材料的弯曲强度,弯曲弹性模量和层间剪切强度较未表面改性时提高了23%,7%和160%;碱–偶联剂复合处理兼顾了碱处理和偶联剂处理的优点,使复合材料弯曲强度、弯曲弹性模量和层间剪切强度分别较未表面改性时提高了26%,18%和572%,综合性能最佳。SEM结果表明,碱–偶联剂复合处理后,复合材料中纤维与树脂之间的界面结合较好。

天然纤维增强聚丙烯基复合材料的制备及静、动态力学性能研究

为研究天然纤维在汽车内饰材料方面的应用,选用棕榈(Palm)、洋麻(Kenaf)纤维与聚丙烯(PP)为原料,采用非织+模压工艺制备了不同纤维体积比的汽车内饰材料,一方面从动态热机械分析(DMA)的角度,以储能模量、损耗因子等为指标,来分析材料的刚性与吸声降噪性能。结果表明,随着纤维体积比的增加,Palm/PP、Kenaf/PP材料的储能模量、损耗模量都呈现一定的线性增加,在体积比为60∶40时达到峰值,并且Kenaf/PP材料的储能模量、损耗模量远高于同体积比下的Palm/PP的储能模量、损耗模量;Kenaf/PP材料的损耗因子曲线比Palm/PP材料的峰值高、温域宽,体积比为60∶40的Kenaf/PP材料温域最大,达到25℃,呈现了更好的减振降噪效果。另一方面从静态力学的角度,借助基于COX剪滞理论的修正混合律公式模量预测模型,对Palm/PP、Kenaf/PP材料的弹性模量进行预测分析。结果表明,模量模型对Kenaf/PP材料的预测精度为90.552%,优于Palm/PP材料的78.697%。

采用SBR法处理麻生物脱胶废水的研究

采用序批式活性污泥法（SBR）处理麻生物脱胶废水,与传统方法相比,废水中的COD、SS显著减少,且占地面积小、耐冲击负荷、污泥产生量少、能有效抑制丝状菌繁殖。当进水COD浓度为582.2～1665.7mg/L、进水SS浓度为106～915mg/L时,COD去除率为 62.8％～86.9％,SS去除率为61.3％～88.6％。研究表明,进水[COD]在1000mg/L以下,宜采用限制性曝气;[COD]在1000mg/L以上,宜采用非限制性曝气。研究了一级生物降解反应动力学,得到了动力学常数K1和不可降解有机物浓度,模拟数据与试验数据吻合良好。

SBR工艺处理麻生物脱胶废水

利用SBR工艺处理麻生物脱胶废水 ,对CODCr、NH3 N的降解轨迹进行跟踪 ,了解废水降解的一般规律 ;研究SBR厌氧段。实验表明在此段中减少的CODCr和NH3 N主要是由于活性污泥的吸附、利用和前一周期置留混合液稀释的共同作用。实验结果也证明当进水CODCr15 0 0mg/L左右 ,负荷≤ 0 74kg/kg·d时 ,废水各项指标均可以达到排放标准 ,而且可以回用到生物脱胶反应器中 ,节约了稀释水。

洋麻纤维精细化处理及性能测试

使用碱氧一浴法和柔软剂对洋麻纤维进行精细化处理,研究精细化处理前后纤维粗糙度、成分、拉伸性能、柔软度以及可纺性的变化.实验结果表明:精细化处理能够有效去除洋麻纤维中的非纤维素物质及表面杂质,使纤维细度降低51.1%,强度提高14.9%,柔软度增加25.1%;可纺性对比实验发现,精细化处理后,洋麻开松落麻率下降10.0%,棉麻混合梳理落率下降37.2%,纱线毛羽指数下降41.8%,强度提高8.6%.

黄麻和红麻纤维磨木木质素的红外光谱特征

从黄麻和红麻纤维中分离出磨木木质素,利用红外光谱分析了两种麻纤维磨木木质素的特征峰及归属,得知磨木木质素中有复杂的官能团,含有羟基、羰基、甲基等基团,木质素结构中含有相当数量的紫丁香基单元。根据黄麻和红麻纤维磨木木质素的红外光谱吸收峰强度,推断其结构属于阔叶木类木质素化学结构GS型木质素。

SBR法处理麻生物脱胶废水

利用 SBR工艺处理麻生物脱胶废水 ,对 CODcr、NH3-N的降解、SBR厌氧段和处理后水是否可回用进行了研究。实验结果证明 ,当进水 CODcr 15 0 0 mg/ L左右 ,MLSS的 CODcr负荷≤ 0 .74kg/ kg· d时 ,废水各项指标均可以达到 GB8978-1996苎麻脱胶废水综合排放二级标准 。

无卤阻燃红麻纤维的制备

以乙二胺和苯基二氯磷酸酯为原料,按其摩尔比1.2∶1.0合成了无卤阻燃单体聚乙二胺苯基磷酸酯(PEP);将PEP与红麻纤维(KF)发生酯化反应,制备了含有P,N元素的酯化阻燃KF;采用物理浸渍法制得浸渍阻燃KF;通过红外光谱、极限氧指数、热失重等手段,对比分析了2种KF的结构和性能。结果表明:酯化阻燃KF的阻燃等级为V-0级,极限氧指数可达56.5%,比浸渍阻燃KF的阻燃性能好,采用化学处理方法是改善KF热稳定性能最有效的方法。

红麻纤维蒸气爆破预处理与酶解糖化条件的优化

为探寻适合红麻纤维蒸气爆破预处理与酶解糖化的技术参数,开展红麻纤维气爆压力、保压时间、填料量等蒸气爆破预处理技术参数研究,并对蒸气爆破预处理后的红麻纤维进行浴比、酶解时间、酶种类、酶配比、酶用量等酶解糖化单因子试验与正交试验。结果表明：红麻纤维气爆预处理以填料量100%、气爆压力2.5 MPa、保压时间240~300 s的效果较好;红麻纤维酶解糖化的较优工艺参数为浴比（1∶5.00）^（1∶7.50）,纤维素酶和木聚糖酶的配比2∶3,采用混合酶（1.50%纤维素酶＋2.250%木聚糖酶）,p H 5.0,糖化率可达70%以上。

洋麻纤维碱氧-浴一步柔软法精细化工艺优化

为了提高洋麻纤维的可纺性,采用碱氧-浴一步柔软方法对洋麻进行精细化处理.利用多指标正交实验方法对总碱浓度、先加入碱浓度、双氧水浓度及碱煮时间这4个参数进行工艺优化设计,通过对纤维细度、断裂强度、柔软度3个指标的综合分析评定最佳处理工艺,并对处理后的洋麻纤维进行基本性能及扫描电子显微镜、傅里叶红外光谱测试.结果表明:最佳处理工艺是总碱质量分数为10%、先加入的碱质量分数为1.2%、双氧水质量分数为1.2%、处理时间为2.5 h;精细化处理的洋麻纤维细度、柔软度、断裂强度分别为13.83 dtex、33.75 r/10 cm、4.13 c N/dtex,与未处理纤维相比,分别降低66.1%、提高25.1%、提高25.9%;扫描电子显微镜及傅里叶红外光谱表明纤维杂质减少,表面粗糙度增加,可纺性提高.

红麻脱胶菌的筛选及其产酶条件

从红麻产地的土壤中分离出一株产果胶酶活性较高的菌株。采用初筛、复筛后获得在果胶平板上透明圈大、酶活最高的菌株c721作为生物脱胶的目的菌，探讨该菌株最适生长条件和最佳产酶条件，最佳生长条件为：氮源为1．5％的酵母浸出液，碳源为0．5％的果胶，pH7．0，温度30℃，培养时间24h。最佳产酶的氮源、碳源分别为酵母浸出液、果胶，培养温度30℃，pH7．0以及产酶高峰期为18～32h。c721菌株对红麻脱胶时间为5d，与天然水沤麻相比时间缩短了55％。