碱、双氧水处理对棉秆皮纤维性能的影响

研究了棉秆皮纤维在碱处理以及双氧水处理过程中,氢氧化钠用量和双氧水用量对其长度、细度、可挠度、残胶率、断裂强度和断裂伸长率的影响.由于纤维的长度、细度、可挠度、残胶率、断裂强度、断裂伸长率均会影响纤维的可纺性能,又因棉秆皮纤维属于工艺长纤维,故纤维的长度可作为次要考虑因素,综合考虑其他影响可纺性能的因素得出,棉秆皮纤维单独碱处理时,氢氧化钠的用量取60～80 g/L为宜;双氧水对棉秆皮纤维的脱胶性能没有明显的影响,其用量为15～20 mL/L时,处理后的棉秆皮纤维性能最好.     

高温脱胶对棉秆皮纤维成分与结构的影响

研究棉秆皮纤维高温脱胶技术,讨论高温时NaOH用量对棉秆皮纤维成分与结构的影响。通过SEM、FT-IR、XRD对棉秆皮纤维高温脱胶前后的表面形态、聚集态结构进行了表征。通过测定脱胶后的黑液残碱量表明反应是否充分。对脱胶后的棉秆皮纤维进行断裂强力测试和热性能分析,从中得出脱胶效果较好的工艺参数。实验结果表明：高温脱胶后的棉秆皮纤维半纤维素和木质素下降明显,纤维素含量提高到接近93%;棉秆皮纤维的断裂强力和热稳定性与碱用量有关。     

棉秆皮的生物脱胶工艺因素分析

针对传统化学蒸煮为主的棉秆皮脱胶方法提取棉秆皮纤维时易产生碱废水污染环境的缺点,采用生物脱胶工艺提取棉秆皮纤维。运用正交试验对棉秆皮的果胶酶脱胶工艺进行了优化,分析了果胶酶制剂的浓度、处理时间、温度、处理的pH值四个因素对生物脱胶的影响。对正交实验的结果进行分析后得出棉秆皮纤维脱胶优化工艺条件是酶制剂浓度12%(owf),温度40℃,时间30h,pH值4.4,浴比1∶30。在优化工艺条件下对棉秆皮纤维的性能进行了测试,结果表明其性能优良。     

微波辅助脱胶棉秆皮纤维的性能和潜在应用

介绍了采用微波辅助升温法对棉秆皮纤维进行定向脱胶的工艺,通过优化脱胶工艺参数制备了线密度小、强度高且能用于复合材料增强基的棉秆皮纤维.结果 表明:在900 W的微波功率、质量分数为8％的NaOH溶液、纤维与脱胶溶液质量比1∶2、微波处理20 s的条件下,可制备出线密度为24.5 dtex的脱胶棉秆皮纤维.脱胶棉秆皮纤维的强度较高(4.1 cN/dtex),其内部结构未发生明显改变,表面能减小.经对比可知,脱胶棉秆皮纤维为增强基的复合材料的拉伸强度、弯曲强度和耐冲击强度分别较未处理纤维/PP复合材料提高了43.3％、74.1％和101.1％.因此,微波辅助脱胶后的棉秆皮纤维可用于复合材料的制备.     

关于棉秆皮纤维增强复合材料的研究

研究表明棉秆皮纤维与麻纤维类似,所以可将其用于复合材料的增强纤维。现提出了棉秆皮纤维的提取工艺以及棉秆皮/环氧树脂增强复合材料的制备方法,并对复合材料性能进行了测试和分析,探讨了棉秆皮纤维的用量对复合材料性能的影响。     

棉秸秆提取天然纤维素纤维的工艺及其纤维形态结构

通过对棉秸秆皮外观观察以及定量测定各段棉秆皮成分含量,确定棉秸秆脱胶提取纤维素纤维分为三段脱胶。对棉秸秆一煮法工艺提取纤维素纤维,采用正交实验,以提取纤维的细度、拉伸断裂强度、残胶率、纤维可挠度为评价指标,通过利用模糊正交法综合评价方法,对不同段棉秸秆提取天然纤维素工艺进行研究。实验得到,第一段棉秆脱胶一煮法优化工艺为：NaOH浓度为35g/L,温度为100℃,时间为2.5h,双氧水浓度为10ml/L,第二段棉秆脱胶一煮法优化工艺为：NaOH浓度为30g/L,温度为100℃,时间为2.0h,双氧水浓度为10ml/L,第三段棉秆脱胶一煮法优化工艺为：NaOH浓度为30g/L,温度为90℃,时间为2.5h,双氧水浓度为8ml/L。通过JSM-6460LV扫描电镜观察了各段棉秸秆提取纤维素纤维的外观形态,提取的天然纤维素纤维属工艺纤维,纤维表面不光滑,且纤维表观粗细不均匀     

棉秆皮高温高压脱胶工艺研究

研究棉秆皮高温高压快速清洁脱胶工艺。介绍了具体的工艺流程,采用二次(几乎正交)旋转组合设计方法,将影响棉秆皮脱胶效果的3个主要工艺因素:NaOH浓度、温度和保温时间进行优化,分析各工艺参数对棉秆皮纤维残胶率、断裂强度和断裂伸长率的影响。试验结果表明:在试验范围内随着NaOH浓度、温度和保温时间的增加,棉秆皮残胶率和纤维断裂强度呈降低趋势;纤维断裂伸长率有所上升。认为:较理想的脱胶工艺为NaOH浓度1.57g/L,温度155℃,保温时间30min。     

棉秆皮机械-生物酶联合脱胶工艺

 本文利用机械-生物酶联合脱胶工艺对棉秆皮进行脱胶。应用模糊数学方法处理机械-生物酶联合脱胶的正交实验评价指标值,解决了两个评价指标优化条件不一致的问题,得出机械-生物酶联合脱胶优化工艺参数为酶浓度6%,pH值4.4,温度60℃,时间8h,棉秆皮纤维的残胶率为8.09%,木质素残余率为9.64%。采用FTIR、SEM和XRD进行测试,讨论了棉秆皮纤维的化学结构、微观表面形态及纤维素结构的变化,为棉秆皮纤维的染色与产品开发提供理论指导。     

脱胶方法对棉秆皮纤维成分及结构的影响

对原棉秆皮不同部位进行化学成分分析,利用常温水沤、常压脱胶及高压脱胶对棉秆皮进行处理,对脱胶后棉秆皮进行化学成分分析．实验结果表明：高压脱胶后棉秆皮纤维中的半纤维素和木质素含量下降最为明显,纤维素含量提高．对不同方法处理后的棉秆皮纤维的长度、线密度进行测量,用SEM、FT-IR、XRD对处理后的棉秆皮纤维表面形态结构、聚集态结构进行了表征,同时对脱胶后的棉秆皮纤维进行强伸性能等测试并得出断裂曲线．     

脱胶方法对棉秆皮纤维成分及结构的影响

对原棉秆皮不同部位进行化学成分分析,利用常温水沤、常压脱胶及高压脱胶对棉秆皮进行处理,对脱胶后棉秆皮进行化学成分分析.实验结果表明:高压脱胶后棉秆皮纤维中的半纤维素和木质素含量下降最为明显,纤维素含量提高.对不同方法处理后的棉秆皮纤维的长度、线密度进行测量,用SEM、FT-IR、XRD对处理后的棉秆皮纤维表面形态结构、聚集态结构进行了表征,同时对脱胶后的棉秆皮纤维进行强伸性能等测试并得出断裂曲线.     

Study on the Application of Kenaf Core as a Composite Reinforcement: Injection Molding of Kenaf Core/Poly(l-lactide) Compounds

Injection molding was performed using poly(l-lactide) (PLLA) as a matrix and by varying the reinforcements, i.e., dry-distilled kenaf core (D-core) or untreated kenaf bast fibers, and the physical properties for these composites were subsequently compared. The dry-distillation was able to reduce the moisture content of D-core by a maximum of 4.2% as compared with untreated control core. As a result, the hydrophobicity was increased, which contributed to favorable Charpy impact strength and tensile properties of the D-core/PLLA composite relative to the kenaf bast fiber/PLLA composite. Moreover, the puffing phenomenon, which arises when heating with a microwave oven due to the vaporization of water dispersed within the interfacial regions and associated softening of the PLLA matrix by the heated vapor, was completely suppressed for the D-core/PLLA composite, whereas a large puffing ratio was observed for the kenaf bast fiber/PLLA composite. Reducing the moisture content also effectively suppressed the occurrence of transesterification reactions, leading to a decrease in the molecular weight of PLLA. However, the apparent nucleation effect of the D-core remains slightly inferior to that for the hydrophilic bast fibers due to its stronger affinity for PLLA molecules.     

Extraction and Characterization of Calotropis gigantea Bast Fibers as Novel Reinforcement for Composites Materials

The aim of this study is to scrutinize the use of Calotropis gigantea bast fibers as potential reinforcement in polymer composites. The bast fibers were extracted from the Calotropis gigantea plant bark and some of them were treated with alkali (5 wt.%) solution. The chemical composition, physico-chemical structural properties of the untreated and the alkali treated Calotropis bast fibers were studied. The results of chemical composition analysis indicated that alkali treatment removed most of the non-cellulose materials as confirmed by the FTIR analysis. The X-ray diffraction results exhibited that the crystallinity index of the alkali treated fibers increased in comparison with the untreated fibers, which agrees with the results obtained in the mechanical tests. The tensile strength and modulus of the alkali treated fibers were found to be higher whereas the elongation at break was lower than the untreated fibers. Thermal stability of alkali treated fibers was lower than that of the untreated fiber. Scanning electron micrographs showed roughening of the surface of the fiber due to the removal of the surface impurities and non-cellulosic components on alkali treatment.It can be concluded that alkali treatment is an effective method to improve the surface and mechanical properties of Calotropis bast fibers to be used in composite materials.     

US consumers’ subjective hand,sensibility, and preference for textile products made of bast fiber

This study was aimed at examining how US consumers perceive the sensibility of bast fiber and to investigate how sensibility is affected by subjective hand and impacts preference. Furthermore, this study discovered how sensibility toward bast fibers leads to preference for different end use. Focus group interviews and questionnaire surveys were conducted and 246 usable data were analyzed. Results revealed that US consumers tend to perceive bast fiber in three sensibility dimensions: ‘Wearable,’ ‘Modern,’ and ‘Rich’. The influence of subjective hand on sensibility was found to differ by sensibility dimensions. The hands of ‘Smooth/Rough’ and ‘Warm/Cool’ were found to be the most significant determinants of sensibility. This study further found that the extent of preference which was predicted by sensibility differed by end use; while consumer preferences toward apparel, bed and bath items and table linen were found to be predicted by sensibility, furnishing, and industrial items were not.     

Extraction and Characterization of Lignocellulosic Fibers from Girardinia Bullosa (Steudel) Wedd. (Ethiopian Kusha Plant)

ABSTRACT

Currently, eco-friendly products have been given great attention as the world is being polluted severely by non-biodegradable products and by-products. Different textile products have their own share in affecting the environment. This research is focused on exploring alternative bast fiber products to support the supply chain and to assess the possibility of using this fiber as a substitute to already available bast fibers. Kusha fiber was extracted and optimized from Ethiopian kusha plant stem – Girardinia bullosa (Steudel) wedd. – using caustic soda solution by varying the concentration, temperature, and time using design expert 6.0.10, quadratic model software. Tensile property, chemical composition, X-ray diffractometer (XRD), Fourier-transform-infrared spectroscopy (FTIR), fiber morphology, and thermogravimetric analysis (TGA) of the fiber were determined. Fiber characterization showed its tensile strength, and the cellulose content was equivalent to or even better than other bast fibers. Morphology of the fiber was similar to that of typical cotton with visible lumen and a slightly flat surface. Therefore, this new extracted fiber has a great potential to be used for different applications such as fiber-reinforced composites, textile furnishing, apparel, and nanocellulose extraction.     

麻纤维的改性及其增强复合材料的研究现状

对常见的几种麻纤维与高性能化学纤维的性能进行简单对比,详述了麻纤维表面改性的研究现状。介绍了国内外麻纤维复合材料的应用情况,指出麻纤维增强复合材料具有广泛的应用前景。     

麻类纺织品的开发前景

介绍了我国麻类纺织品的生产现状以及麻类纤维功能研究的进展情况，阐述了各类麻纺织产品开发的重点和前景。     

胡麻双螺杆法皮杆分离后的制浆性能研究

本文主要研究双螺杆法分离胡麻韧皮部和木质部纤维所得纤维的制浆性能,以及加入NaOH等药品对其制浆性能的促进作用。结果发现,双螺杆法可使胡麻韧皮部和木质部纤维得以很好的分离(总得率可达40.4%),加入药品后韧皮部纤维100g/m2定量纸张的抗张和撕裂指数以及耐折度可达56.36 N.m/g、42.84 mN.m2/g和168次,比不加药品是高出了25%、30%和60%左右。与此同时,木质部纤维在经过磨浆处理后也可成浆,其50g/m2定量纸张的抗张和撕裂指数以及耐折度可达42.47N.m/g、5.30 mN.m2/g和10次,与不加药品相比提高了约100%、70%和200%。因此,综合可知,双螺杆法可将胡麻韧皮部和木质部纤维得以较好的分离,加入一定量NaOH等化学药品可提高其制浆性能,最终可针对两种纤维的性质,将二者进行合理利用,提高胡麻作为制浆造纸原料的利用效率。     

Degumming of ramie bast fibers by Ca2+-activated composite enzyme

In recent years, special attention has been paid to the application of biotechnology in the textile industry. In this study, composite enzyme (contained pectatelyase/hemicellulase/laccase) was employed to degum the ramie bast successfully. Interestingly, the activities of enzymes were enhanced by promotion of Ca²⁺ activated remarkably. The test of degummed ramie fiber performance demonstrated that fiber fineness, breaking strength, whiteness, and residual gum of fibers have greatly improved. Further, the structure and morphous of the fibers before and after degumming was examined and analyzed. The results showed that the gum, hemicellulose, and lignin were removed effectively and treated fibers had the typical cellulose I structure suitable for direct textile and other applications. These outcomes suggested that Ca²⁺-activated composite enzyme could degum the gum of ramie bast effectively, which provided a method to improve the quality of ramie fibers and a theoretical basis for flax degumming technique on an environmentally-friendly basis.