天然纤维织物的转移印花研究

本文介绍了转移印花的原理,重点论述了天然纤维织物转移印花采用FP法预处理,然后用分散染料进行转移印花的原理和方法,筛选了天然纤维织物转移印花用分散染料,并提出了天然纤维织物转移印花的工艺。     

Microstructural and Mechanical Characterizations of Natural Long Alfa Fibers Obtained with Different Extractions Processes

This study investigates the morphological changes and tensile properties of Alfa fibers extracted mechanically after two treatments namely water retting and alkali treatment. The Scanning Electron Microscopy technique is used in this experimental work. The main observation reveals the decrease of noncellulosic component in the fibers which is inversely proportional to the concentration of sodium hydroxide solution in the case of the alkali treatment. Tensile tests were carried out using tensile machine for determining the tensile properties mainly the tensile strength and the elastic modulus. The tensile strength and young’s modulus of retted fibers are assumed constant. The results relative to the alkalized fibers show an improvement of tensile strength and young’s modulus and are proportional to the sodium hydroxide concentration up to 14%.     

再生竹纤维素纤维热学和拉伸性质的研究

利用DTG和DSC技术对再生竹纤维素纤维的热学性质进行了测试和分析,测试结果显示,再生竹纤维素纤维的DTG和DSC曲线与其他纤维素纤维相似,随着温度升高,纤维因水分蒸发而损失质量,约120℃时达到稳定;230-240℃时,纤维中的油剂开始分解;空气中,再生竹纤维素纤维305.7-330.2℃发生热裂解;氮气中,竹纤维素纤维的热裂解从310.5℃开始,到351.1℃结束。竹纤维素纤维在升温过程中没有出现熔融现象,其湿润状态下的断裂强力和断裂伸长率均较干态为低。     

Solid State 13C NMR and Diffuse Reflectance Mid-Infrared Spectroscopic Analysis of the Effects of Retting on the Chemical Composition of KenafFibre

Bast ribbons from Tainung 1 (T₁) and Guatemala 45 (G₄₅) cultivars of kenaf ( Hibiscus cannabinus ) were subjected to a chemical retting process. The resulting changes at the base and tip regions of each cultivar were analysed using solid-state ¹³C NMR and diffuse reflectance mid-infrared spectroscopies. Chemical retting was performed by boiling the substrates in NaOH (70 g litre⁻¹) +NaHSO₃ (5 g litre⁻¹) for 1 h, after which they were neutralised, washed and air dried. This process produced large decreases in the non-cellulosic components, though 25% of the phenolic component was left undegraded, and cellulose crystallinity was increased by ∽5% over that in unretted samples.     

Evaluation of physico-mechanical characteristics of cashew nut shell liquid-epoxy composites with Borassus and Tamarind fruit fibres as reinforcements

In this study, Cashew Nut Shell Liquid (CNSL)-epoxy matrix-based composites reinforced with borassus and tamarind fibres were fabricated using compression moulding technique. Three different types of composites were fabricated, namely Borassus fruit fine fibre/CNSL-epoxy composites (BF composites), Tamarind fibre/CNSL-epoxy composites (TF composites) and Tamarind/Borassus fruit fine fibre CNSL-epoxy hybrid composites (HB composites). In addition, CNSL-epoxy neat polymer was also fabricated for comparison. Physical properties such as micro-hardness, void percentage, and mechanical properties like tensile, flexural, Interlaminar Shear Strength (ILSS), and impact strength were investigated. Scanning Electron Microscope (SEM) was used to study the failure mechanism of the composites. Experimental results indicate that tensile and flexural properties of BF composites were higher when compared to TF and HB composites. Micro-hardness and impact strength of HB composites were better than the others. SEM images indicated better fibre-matrix bonding in BF composites indicating improved resistance to delamination. Thus, borassus and tamarind fibre reinforced CNSL-epoxy composites can be used as an alternative material for light to moderately loaded structural engineering applications.     

纤维素及其衍生物作为3D打印材料的研究综述

3D打印作为革命性的新型制造技术,具有光明的未来与广阔的前景。打印材料作为3D打印研究的重点,为满足多样化的需求仍需要继续探索。纤维素作为自然界中最常见的天然聚合物和植物的主要成分,存在多种优势,在生物基产品的制备中具有巨大潜力。目前,纤维素作为3D打印材料的研究已成为领域热点,得到了高度关注。本文将纤维素及其衍生物作为3D打印材料的研究进行综合整理,总结了纤维素及其衍生物在打印材料中作用和功能,以及纤维素类打印材料在3D打印中的应用,分析了纤维素类打印材料在3D打印中面临的挑战和未来发展前景。     

羟（甲、乙、丙）基纤维素/明胶共混复合膜的制备和性能研究

以明胶为基体,甘油为增塑剂,羟甲基纤维素(HMC)、羟乙基纤维素(HEC)、羟丙基纤维素(HPC)分别为增强相,通过添加不同量的羟(甲、乙、丙)基纤维素,分别制备不同含量的羟(甲、乙、丙)基纤维素/明胶共混复合膜;采用扫描电子显微镜、智能电子拉力试验机、差示扫描量热仪和热缩试验仪对共混复合膜的表面形貌、力学性能和热稳定性进行表征。结果表明,随着共混复合膜中纤维素含量的增加,各复合膜的断裂伸长率和抗拉强度呈先提高后降低的趋势;达到最大抗拉强度时,各共混复合膜中羟基纤维素的含量分别为HMC 1%(38.4 MPa)、HEC 1%(35.3 MPa)、HPC 0.5%(32.1 MPa);各共混复合膜热稳定性均提高,而热缩率降低。添加羟基纤维素可增强共混复合膜的力学性能和热稳定性,但不同羟基纤维素作为增强相时,增强效果存在一定差距。     

竹原纤维结构和力学性能研究

文章主要研究了竹原纤维的基本形态特征;同时对竹原纤维的力学性能特点作了详细分析.     

Preparation and characterization of PSA/nano-TiO2 composites and fibers

Polysulfonamide/nano titanium dioxide (PSA/nano-TiO₂) composite spinning solutions with various nano-TiO₂ mass fractions were prepared using the solution blending method. The corresponding composite fibers were developed by wet-spinning technology and the composite membranes were prepared using the digital spin-coating technique. The properties of PSA/nano-TiO₂ composite fibers and membranes were investigated by scanning electron microscope, Fourier transform infrared spectroscopy and X-ray diffraction, etc. The effects of nano-TiO₂ and its mass fractions on the mechanical properties, thermal stability and ultraviolet resistance of PSA composites were also analyzed. The experimental results showed that nano-TiO₂ with low mass fractions can be dispersed evenly in the PSA matrix; the blending of nano-TiO₂ had no obvious influence on the molecular structure and the chemical composition of PSA fiber; the crystallization in PSA fiber was promoted at low nanoparticles mass fractions because it can act as a nucleation agent; the mechanical properties and the thermal stability of PSA/nano-TiO₂ composites can be enhanced obviously by blending nano-TiO₂ into PSA matrix. The ultraviolet resistance of PSA composites can be improved significantly with the increasing nano-TiO₂ mass fractions and the 7 wt.% specimen showed the lowest UV transmittance.     

超高压处理对LDPE、PA6食品包装材料包装性能可逆性的研究

本文在不同条件下对LDPE、PA6进行超高压(HPP)处理,测定不同压力、保压时间及存储时间对材料拉伸强度、热封性能、阻隔性能、热性能以及包装性能可逆性的影响。实验表明:处理压力、保压时间及存储时间对2种材料的热封性均未产生显著影响,但LDPE、PA6试样的拉伸强度随压力升高明显增大;当压力300 MPa时LDPE的透湿性逐渐上升,当压力300 MPa时LDPE的透湿性又逐渐降低,对PA6来说,当压力100 MPa时,材料的透湿性明显下降由10.13 g/(m2·d)(0.1 MPa/10 min)降低到6.79 g/(m2·d)(200 MPa/10 min),但随压力增大透湿性下降的幅度并不明显;两种材料的熔融焓在HPP下均有升高,当存储24 h后,两种材料的ΔH又有所恢复;与0.1 MPa下相比,经过HPP后对异丙基甲苯在LDPE(500 MPa)和PA6(100 MPa)薄膜中的渗透率分别降低约50%和58%,但随着存储时间的延长又逐渐恢复至常压下的渗透率。研究发现实验中采用的LDPE和PA6 2种薄膜的包装性能均有可逆现象出现。     

酸性电解水爆破处理灵芝废段木效果研究

随着灵芝产业的不断壮大,每年因种植灵芝而产生大量废段木。该文在对废段木组成成分分析的基础上,研究了酸性电解水爆破处理废段木酶解工艺。废段木经酸性电解水预煮后高温瞬时爆破处理来破坏组织结构及纤维素结晶状态,以半纤维素去除率和纤维素损失率为考察指标,通过单因素试验及正交试验确定了反应的最优爆破条件为酸性电解水pH 1.8、爆破温度180 ℃、爆破时间60 s、预煮液固比为20:1（mL:g）。此最佳条件下半纤维素的去除率为94.20%,纤维素的溶出率为12.57%;经酸性电解水爆破处理后酶解率达86.40%,爆破残渣酶解效果表明利用强酸性电解水爆破处理灵芝废段木能够有效破坏纤维素结晶状态,利于纤维素酶酶解。     

Effect of Filler Content of Chemically Treated Short Bagasse Fiber-Reinforced Cardanol Polymer Composites

In this work, the sugarcane bagasse fiber was used as a filler to make a new type of biodegradable composite, using the cardanol resin, as a fully biodegradable thermosetting polymer matrix. Biocomposite performance was improved by chemically modified bagasse fiber using alkaline treatment. Two sets of composites were prepared with a fiber length of 10 and 20 mm with various weight percentages viz., 0, 5, 10, 15, and 20 of cardanol resin using a compression molding machine. The mechanical properties were studied using some tests and the morphological study in flexural fractured specimens was carried out using SEM. The thermal properties of biodegradable polymer composites were evaluated using TGA. The chemical formation of the new biocomposites was also examined by the FT-IR spectroscopy technique. The result proved that the morphology of the composites has improved the bonding between the fiber and resin, thus leading to enhancement of the mechanical properties. The result had shown the tensile and flexural strength with an increase in the range of bagasse fiber up to 15 wt% in both the sets. The TGA results showed that biocomposites of 15 wt% in both sets had the highest thermal stability. This investigation recommended the possibility of introducing bio-fiber obtained from waste agricultural residues in polymer matrix composites.     

自然发酵工艺对米粉流变学性质的影响

本文通过对自然发酵米粉的理化性质和流变性的研究,探讨传统自然发酵对米粉感官性质的作用机理。研究发现发酵过程中总淀粉及直链淀粉含量变化不显著,蛋白、脂肪和灰分含量减少,而游离脂肪酸的含量上升。流变学测定发现,发酵法生产的米粉相对于对照样品最大破断应力减小而最大应变增加。快速黏度分析仪(RVA)测定表明发酵样品的RVA粘度减小、糊化温度降低。感官评定结果表明发酵法生产的米粉柔韧筋道,品质更好。     

造纸法制备碳纤维增强热塑性复合材料的研究

本研究以短切碳纤维为增强体,聚丙烯(PP)纤维为基体,采用湿法造纸工艺制备碳纤维增强热塑性复合材料(CFRTP)。通过正交实验,探讨了碳纤维含量、碳纤维长度、热压温度以及热压时间对CFRTP力学性能的影响。结果表明,碳纤维含量是影响复合材料力学性能的主要因素;正交实验条件下,当碳纤维含量20%,碳纤维长度5 mm,热压温度190℃,热压时间10 min时,CFRTP的性能最好,其拉伸强度为83.9 MPa,弯曲强度为52.5 MPa,缺口冲击韧性48.2 kJ/m~2,对比同等条件下未添加碳纤维的材料其性能分别提高了189%、52%以及1021%。同时,通过单一因素实验探究不同碳纤维含量对CFRTP力学性能的影响。结果表明,随着碳纤维含量的增加,CFRTP的拉伸强度、弯曲强度以及缺口冲击韧性均先上升后下降。     

Evaluation of Phormium Cookianum Fibers as Reinforcements for Polypropylene-based Composites

ABSTRACT

Due to the abundance of vegetable fibers from the large variety of existing plant types, many of them have not yet been explored in terms of mechanical behavior as composite reinforcements. Most of the natural fibers composites are based in a few crop fibers leaving a large number of species without a comprehensive study. This work evaluates the tensile strength of fibers from Phormium cookianum. Scanning electron microscopy images were taken on the fiber surface after the mercerization process, as well as in the composite. Through these results, it can be identified that the damage caused to the surface of the fibers may directly influence the adhesion that occurs at the interface with the polymer. In general, the composites produced here have good mechanical properties with a low cost of production. On this basis, this product has the potential to replace panels, boards, injection and molded parts.     

纳米微晶纤维素/阳离子淀粉涂布对食品包装用纸性能影响的研究

为了提高食品包装用纸的阻隔及机械性能,以玉米淀粉为原料制备阳离子淀粉(CS),并与纳米微晶纤维素(NCC)复配制备一种复合施胶剂,然后在牛皮纸原纸表面涂布,研究了NCC含量对涂布后牛皮纸的水蒸气阻隔性、吸水性、抗油性、透气性及抗张强度的影响.结果表明,NCC含量为15％时,NCC/CS涂布牛皮纸的阻隔性和抗张强度最好,...     

Effect of grafting generations of poly(amidoamine) dendrimer from the sisal fiber surface on the mechanical properties of composites

In order to improve the mechanical properties of sisal fiber-reinforced polypropylene composites, the sisal fibers were grafted with poly(amidoamine) dendrimer and the effects of grafting generations on the mechanical properties of composites were studied. The results reveal that the tensile, flexural, and impact strength of the composites are improved considerably with the poly(amidoamine) dendrimer grafting treatment. For the 2.0 generation treatment with the poly(amidoamine) dendrimer, the tensile, flexural, and impact strength of the composites at 30 wt% fiber loading increase by 29%, 13%, and 54%, respectively. However, the thermal and mechanical properties of the sisal fibers decrease after prolonged grafting treatment.     

谷物磨粉工艺对其淀粉损伤及特性影响研究进展

谷物磨粉主要采用机械粉碎方式,在粉碎过程中必然造成淀粉颗粒不同程度的损伤,使其产品中的破损淀粉含量显著增加,而破损淀粉含量又直接影响着谷物的加工品质和食用品质。本综述系统阐述了不同磨粉工艺对谷物制品中淀粉损伤的影响及其产生原因,并对谷物制品品质改良进行了展望,以期为我国谷物加工技术及其品质改善提供参考。