以离子液体为溶剂的纤维素纤维的结构与性能

以离子液体氯化1-丁基-3-甲基咪唑([BMIM]Cl)为溶剂,制备了纤维素/[BMIM]Cl溶液,探讨了该体系的流变性能,并对所纺得的纤维素纤维的结构与性能进行了分析。结果表明:纤维素/[BMIM]Cl溶液为切力变稀流体,当剪切速率较大时,温度对体系黏度几乎没有影响,因此可以在较高剪切速率下降低纺丝温度;由该体系纺制的纤维具有纤维素II晶型的结构;随着拉伸比的提高,纤维的取向程度及结晶度增大,从而使纤维力学性能提高,所得纤维的表面光滑、结构致密,其染色性能及抗原纤化性能与Lyocell纤维基本相近。从而证明了用离子液体[BMIM]Cl所纺制的纤维素纤维性能良好,可望成为继Lyocell纤维之后的又一新型绿色纤维素纤维。     

剑麻增强醋酸纤维素复合材料的制备与性能研究

对剑麻(SF)进行乙醚化处理以改性纤维结钩和性能,得到改善纤维(ASF)。并通过挤出、模压工艺制备了剑麻增强醋酸纤维索(CA)复合材料。从纤维长度、结钩、热性能等力一面研究改性和加工工艺对SF的影响,同时研究了复合材料的力学性能。研究结果表明,SF和ASF使复合材料的拉伸性能和弯曲性能都得到了一定的增强。尽管ASF/CA复合材料在强度和模量上比SF/CA复合材料硝有逊色,但是由于ASF与基体相容性提高、柔韧性改善,从而其ASF/CA复合材料在断裂伸长率和冲山性能上优于SF/CA复合材料。     

Cellular,Mineralized, and Programmable Cellulose Composites Fabricated by 3D Printing of Aqueous Pastes Derived from Paper Wastes and Microfibrillated Cellulose

Combining recycling of paper wastes (WPs) with extrusion‐based additive manufacturing represents a sustainable route to cellular cellulose composites tailored for lightweight construction. Particularly, shear mixing of shredded WPs with an aqueous solution of a polymer binder like polyvinyl alcohol (PVA) yields aqueous pastes suitable for 3D printing. As a shear thinning additive, both WP and microfibrillated cellulose account for enhanced shear thinning and dimensional stability. Opposite to the formation of dense WP/PVA composites by melt extrusion, 3D printing of aqueous pastes produces cellular cellulose/PVA composites exhibiting hierarchical pore architectures. In spite of low densities around 0.8 g cm^?3, high Young's modulus (2.0 GPa) and tensile strength (53 MPa) are achieved. Mechanical stability, water resistance, and even flame retardancy simultaneously improve by crosslinking with glyoxal and especially by mineralization. Multimaterial 3D printing combines the 3D dispensing of cellulose/PVA pastes with the simultaneous, staged, or subsequent spraying of aqueous water glass to enable mineralization of composite surface, bulk, and interlayers. Furthermore, the glyoxal‐mediated crosslinking affords thermo‐ and moisture‐responsive cellulose/PVA composites with programmable shape change induced either by heating at 100 °C or by exposure to moisture at 37 °C.     

PP/碳纤维纸夹芯“三明治”复合材料性能

以碳纤维纸(CFP)作为芯材,聚丙烯(PP)作为皮材,用平板硫化机热压制成PP–CFP–PP"三明治"式复合材料,并测试了复合材料的各项力学性能。结果表明,加入CFP后复合材料的力学性能总体上有所改善,针对不同PP基体、CFP对复合材料力学性能的改善方式有所不同,对基材本身强度/刚度小的复合材料增强/增刚效果明显,而对于基材本身强度/刚度大的复合材料,加入CFP后其断裂伸长率、无缺口冲击强度提高明显,同时复合材料的缺口冲击强度有所降低。     

高压均质化处理对微纤化纤维素性质的影响

以竹浆为原料,结合前期的磨浆机(PFI磨)磨浆和化学氧化预处理,研究了高压均质化处理对制备微纤化纤维素(MFC)产品的纤维表面形态及保水值的影响,并确定了最优均质化处理工艺。结果表明,高压均质化处理对纤维具有明显的破壁作用,随着均质化处理次数的增加,纤维的比表面积逐渐增大;同时,通过均质化处理次数与MFC保水值之间的关系,建立起了两者之间的数学模型,从而可以通过控制均质化处理次数来得到具有不同保水值的MFC产品,为MFC的制备提供指导;另外,高压均质机的主腔孔径对MFC保水值也有较大影响,在其它处理条件相同的情况下,主腔孔径越小,所得MFC的保水值越大。     

羧甲基纤维素钠/海藻酸钠共混纤维的制备与性能测试

以H2O为溶剂、CaCl2为凝固剂,采用湿法纺丝技术制得羧甲基纤维素钠(NaCMC)/海藻酸钠(NaAIg)共混纤维。通过对纺丝液的流动性以及纤维的纤度、断裂强度、断裂伸长率和吸湿性能的测试,研究了不同NaCMC添加量对共混纤维的性能的影响。结果表明:当NaCMC的相对百分含量为15%时,可得到各种性能优良的共混纤维;用生物显微镜观察到纤维表面有沟槽,横截面为圆形,边缘为锯齿状。     

回收聚丙烯/废书刊纸纤维复合材料结构与力学性能的研究

以废书刊纸纤维(OMGF)和回收聚丙烯(PP)为原料,马来酸酐接枝聚丙烯(MAPP)为相容剂,采用热压成型法制备了PP/OMGF木塑复合材料。研究了OMGF含量对复合材料拉伸性能及弯曲性能的影响,并采用红外光谱和扫描电子显微镜分析了OMGF的结构及复合材料的拉伸断面形貌。结果表明,OMGF对PP基体具有一定的增强作用,当OMGF含量为30%时,复合材料的拉伸强度和弯曲强度分别达到最大值29.53MPa和33.67MPa,比回收PP分别提高了51.6%和31.7%;随着OMGF含量的增加,复合材料的断裂伸长率逐渐下降,弯曲模量逐渐上升。扫描电子显微镜分析显示,当OMGF含量较低时,其与PP基体之间具有良好的界面相容性;当OMGF含量增加到50%时,界面相容性明显下降。     

棉浆和木浆掺混纺醋酸纤维素纤维结构与性能的分析

对棉浆和木浆三种掺混纺比例(棉浆与木浆的掺混纺比例为0∶100,50∶50,100∶0)的醋酸纤维素纤维的结构与性能进行了测试分析。采用光学显微镜观察、纤维图形分析软件计算、X射线衍射和强伸性能测试,对比分析了三种掺混纺比例纤维的截面形态、结晶度、取向度、断裂伸长率、断裂强度以及初始模量,为棉浆与木浆掺混纺醋酸纤维素纤维的广泛应用提供了理论依据。实验结果表明:三种掺混纺比例纤维的截面形态指标无显著差异,内部晶体基本结构相同,随着棉浆与木浆掺混纺比例的增加,结晶度、取向度以及强伸性能呈现出略微增大的趋势。     

ZnCl_2制备再生纤维素纤维对纸张增强的研究

用65%（wt）ZnCl2水溶液,在温度80℃、搅拌速度300 r/min、不同反应时间下溶解针叶木浆,用水作为凝固剂,制备再生纤维素纤维（简称RGC）。研究不同反应时间制备的RGC及RGC添加量对纸张物理强度的影响。利用透射电镜（TEM）、傅里叶变换红外光谱（FT-IR）、X-射线衍射（XRD）、热重分析（TGA）技术对RGC的结构和性能进行表征。研究结果表明,在120 min下制备的RGC及RGC添加量为40%时纸张的物理强度最佳,与空白纸样相比,紧度提高22.77%,抗张指数提高291.5%,耐破指数提高50.64%,耐折次数从1提高至549。     

芳香型再生纤维素纤维的研究进展

简述了近年来国内外芳香纤维及产品的研究进展,综述了芳香纤维生产中存在的问题,概述并展望了芳香纺织品的应用领域和发展趋势。     

玻纤含量对长纤维增强聚丙烯性能的影响

通过熔融浸渍工艺制备了长玻纤增强聚丙烯复合材料(LFT–PP),利用力学性能测试、差示扫描量热分析、热重分析、扫描电子显微镜(SEM)观察等方法研究了玻纤含量对LFT–PP性能的影响。结果表明,当玻纤质量分数为50%时,复合材料力学性能最佳,其拉伸强度达到158.7 MPa,为纯PP的5.7倍;缺口冲击强度为52.6 kJ/m2,是纯PP的10.7倍。从SEM照片可以看出,玻纤与PP树脂有很好的相容性,使得复合材料具有极佳的力学性能。     

改性酪蛋白/羧甲基纤维素钠共混纤维制备与性能

采用湿法纺丝,以乙醇、氯化钙和盐酸的混合溶液为凝固浴制备了改性酪蛋白(CLC)/羧甲基纤维素钠(CMC-Na)共混纤维。通过测试纺丝液流动性以及纤维的红外光谱、表面形态和力学性能,研究了CLC和CMC-Na不同配比与纺丝溶液pH改性后酪蛋白纤维的力学性能增加,纺丝溶液的流动性与CMC-Na维的红外光谱分析表明CLC与CMC-Na之间有良好的相互作用。CMC-Na质量分数为30%(相对于改性酪蛋白)的共混纤维性能较好,纤维表面较致密,有沿着纤维轴向取向的明显条纹,其断裂强度为341.19MPa。     

微晶纤维素含量对PE-HD复合材料性能的影响

采用熔融共混法制备了微晶纤维素（MCC）含量分别为50 ％、60 ％和70 ％的高密度聚乙烯（PE-HD）/MCC复合材料,研究了MCC含量对其力学性能、流变行为、热变形温度和断口形貌的影响。结果表明,加入MCC能有效提高PE-HD的弯曲强度、弯曲模量和拉伸强度,其中MCC含量为60 ％时材料力学性能最好;MCC的加入显著提高了PE-HD的热变形温度,且MCC含量为60 ％时复合材料热变形温度最高;PE-HD/MCC复合材料断口形貌分析表明MCC在基体中分布较均匀,MCC含量为60 ％时与PE-HD基体的相容性最好。     

纤维素新溶剂的研究进展

归纳总结了国内外3种传统的生产纤维素纤维的方法及纤维素溶剂的研究进展,进一步分析比较了各种溶剂体系的优缺点,在此基础上对我国粘胶行业的发展和纤维素新溶剂的研究进行了展望。     

MWCNTs含量对纤维素/[BMIM]Cl溶液及其纤维性能和形态结构的影响

分析了经表面功能化的MWCNTs(多壁碳纳米管)在纤维素/[BMIM]Cl(1-丁基-3-甲基咪唑氯盐)体系中的分散稳定性,探讨了MWCNTs/纤维素/[BMIM]Cl溶液的流变行为,并通过干湿法制备了不同MWCNTs含量的离子液体法纤维素纤维,对其力学性能和表面形态结构进行了研究。结果表明:MWCNTs/纤维素/[BMIM]Cl溶液为切力变稀流体。随着溶液中MWCNTs添加量的增加,溶液表观黏度先增大后减小;适量的MWCNTs可以均匀分散在纤维素/[BMIM]Cl溶液体系中并具有良好的可纺性,所制得的MWCNTs/纤维素纤维表面较光滑且力学性能明显改善。其中,含1%MWCNTs的纤维素纤维的初始模量和断裂强度较高,分别比未添加MWCNTs的纤维提高66.7%和22.7%。     

Emerging Biodrying Technology for the Drying of Pulp and Paper Mixed Sludges

Effective sludge management is increasingly critical for pulp and paper mills due to high landfill costs and complex regulatory frameworks for options such as sludge landspreading and composting. Sludge dewatering challenges are exacerbated at many mills due to improved in-plant fiber recovery coupled with increased production of secondary sludge, leading to a mixed sludge with a high proportion of biological matter that is difficult to dewater. Various drying technologies have emerged to address this challenge of sludge management, whose objective is to increase the dryness of mixed sludge to above critical levels (≈42% dryness) for efficient and economic combustion in the boiler for steam generation. The advantages and disadvantages of these technologies are reviewed in this article, and it is found that many have significant technical uncertainties and/or questionable economics. A biodrying process, enhanced by biological heat generation under forced aeration, is introduced that has significant promise. A techno-economic analysis of the batch biodrying process at a case study mill showed an annual operating cost savings of about $2 million, including the elimination of landfilling practices and supplemental fuel requirements in the boiler. It was shown that if a biodrying residence time of less than 4 days can be achieved, payback periods of 2 years or less can result in many mills. The potential for the development of a continuous biodrying reactor and the fundamentals of its mathematical modeling are thus presented. Compared to the batch reactor configuration, it is expected that the continuous process would result in improved process flexibility and controllability, lower investment and operating costs due to shorter residence times, and an improved potential to fit into the crowed pulp and paper mill site.     

Emerging Biodrying Technology for the Drying of Pulp and Paper Mixed Sludges

Effective sludge management is increasingly critical for pulp and paper mills due to high landfill costs and complex regulatory frameworks for options such as sludge landspreading and composting. Sludge dewatering challenges are exacerbated at many mills due to improved in-plant fiber recovery coupled with increased production of secondary sludge, leading to a mixed sludge with a high proportion of biological matter that is difficult to dewater. Various drying technologies have emerged to address this challenge of sludge management, whose objective is to increase the dryness of mixed sludge to above critical levels (≈42% dryness) for efficient and economic combustion in the boiler for steam generation. The advantages and disadvantages of these technologies are reviewed in this article, and it is found that many have significant technical uncertainties and/or questionable economics. A biodrying process, enhanced by biological heat generation under forced aeration, is introduced that has significant promise. A techno-economic analysis of the batch biodrying process at a case study mill showed an annual operating cost savings of about $2 million, including the elimination of landfilling practices and supplemental fuel requirements in the boiler. It was shown that if a biodrying residence time of less than 4 days can be achieved, payback periods of 2 years or less can result in many mills. The potential for the development of a continuous biodrying reactor and the fundamentals of its mathematical modeling are thus presented. Compared to the batch reactor configuration, it is expected that the continuous process would result in improved process flexibility and controllability, lower investment and operating costs due to shorter residence times, and an improved potential to fit into the crowed pulp and paper mill site.     

Interfacial Properties of Ethyl Cellulose/Cellulose Acetate Blends by HPLC

The high performance liquid chromatography method (HPLC) with ethyl cellulose/cellulose acetate (EC/CA) blends and EC as column packing material, and small molecular weight compound as probe molecules was employed to measure the retention volume (VR) and equilibrium distribution coefficient (K) of both inorganic and organic solutes. The interfacial separation properties of EC/CA blends were characterized by the HPLC data. The effects of the blends on the interfacial adsorption properties, hydrophilicity, affinity, polar and non-polar parameters of EC membrane materials were studied subsequently. The research results indicate that the interfacial adsorption properties and hydrophilicity of EC have been improved by solution blending with CA. The alloys are superior to EC in the separation efficiency for non-dissociable polar organic solute. The EC/CA alloy (80:20, w) is suitable for desalting and desaccharifying.     

乳胶粉掺量对纤维素醚改性水泥浆体流变性能的影响

采用Anton Paar MCR 302型流变仪研究了乳胶粉掺量对纤维素醚改性水泥浆体流变性能和触变性的影响.结果表明,掺入乳胶粉的纤维素醚改性水泥浆体表现为剪切稀化的流变特性,当剪切速率较小时,浆体黏度下降显著.乳胶粉掺量越大,浆体基于Herschel-Bulkey模型拟合得到的屈服应力和黏度系数均越大.并且乳胶粉能...     

抗菌蔗渣浆纤维的制备及其性能研究

以漂白蔗渣浆为原料、3-氯-2-羟基丙基三甲基氯化铵为抗菌剂,在碱性条件下发生醚化反应,制备具有广谱抗菌性能的抗菌蔗渣浆纤维。研究了接枝率、接触时间、菌液浓度、洗涤次数对抗菌蔗渣浆纤维抑菌率的影响,试验表明:当接枝率为3%时,抗菌蔗渣浆纤维对大肠埃希菌、金黄葡萄球菌、白念珠菌的抑菌率均为100%;且经过20次洗涤后,抗菌蔗渣浆纤维的抑菌率仍在90%以上,耐洗涤性能好。抗菌蔗渣浆纤维可用于制备具有抗菌性能的食品包装纸,进而实现蔗渣浆纤维的高值化利用。