高原纤化Lyocell纤维的制备及性能——(Ⅰ)溶胀剂NaOH溶液质量分数的影响

Lyocell纤维具有易原纤化的特性,但通过对其原纤化进行调控,也能带来许多优点,扩大其应用领域。文中以不同质量分数的NaOH溶液为溶胀剂,采用超声波振荡法制备了不同原纤化程度的Lyocell纤维,并探讨了NaOH质量分数对其结构与性能的影响。结果表明,随着NaOH质量分数的提高,Lyocell纤维的原纤化程度先增大后变小,当NaOH质量分数为3%时,纤维的原纤化程度最显著。采用保水值和比表面积均可表征Lyocell纤维原纤化程度,两者变化规律一致,当NaOH质量分数为3%时,纤维的保水值和比表面积分别提高了118.9%和47.9%。纤维的结晶度随NaOH质量分数的增大而略有提高;当NaOH质量分数较低时,对纤维力学性能影响较小。     

聚对苯撑苯并二(口恶)唑原纤化纳米纤维制备技术及结构性能

聚对苯撑苯并二(口恶)唑(PBO)纤维是一种具有多重原纤结构的高分子聚合物.通过机械力作用可以使PBO纤维发生原纤化,制备具有直径小于100 nm的PBO原纤化纳米纤维.文中对PBO纤维发生原纤化的历程及机理进行研究,扫描电镜观察发现PBO纤维的原纤化过程包括:脱除皮层、主干破坏、进一步原纤化等阶段,剥离和劈裂是原纤化的主要方式.经过原纤化处理的PBO纤维,呈现不同尺寸纤维组成的多分散体.打浆度70°SR的PBO原纤化纳米纤维的直径可达到50 nm,其保水值118％,纤维长度分布主要集中在0.3～0.5 mm,比表面积21.89 m2/g.以PBO原纤化纳米纤维为原料,通过湿法成形方式在抄纸系统上制备的纸基材料力学性能随着原纤化程度增加而增加.     

半纤维素对Lyocell纤维结构与性能的影响

本文对比研究了具有不同半纤维素含量的Lyocell纤维的结构与性能。探讨了半纤维素对Lyocell纤维聚集态和超分子结构的影响,并且测定了半纤维素对Lyocell纤维力学、抗原纤化和染色性能的影响。     

半纤维素包装薄膜材料的研究进展

目的 综述了近几年来有关半纤维素改性、材料制备及其应用方面的研究,以期为半纤维素基薄膜材料的进一步开发与应用提供参考。方法 通过收集与整理相关文献,阐述半纤维素的结构特点和分离提取方法,综述近些年来关于半纤维素包装薄膜材料的研究进展,并对比分析物理改性与化学改性2种改性方法对半纤维素薄膜材料包括阻隔性能、力学性能等的调控。结论 对半纤维素进行物理或者化学改性,在保留原有优势性能的同时赋予半纤维素薄膜材料更好的机械强度、柔韧性、热稳定性以及疏水性等性能,符合半纤维素高值化利用新趋势。     

单硬脂酸甘油酯改性蓖麻油基水性聚氨酯的制备与性能研究

目的 使用单硬脂酸甘油酯(GMS)对蓖麻油基水性聚氨酯进行改性,增强其防水、耐热和力学性能。方法 使用丙酮法合成不同GMS含量的蓖麻油基水性聚氨酯乳液,进行乳液粒径测定和稳定性试验;使用浇铸法制作薄膜,并进行铅笔硬度测试、力学性能测试、吸水测试、接触角测试、热重测试、DSC、FTIR测试。分析薄膜表面硬度、力学性能、耐水性能、热稳定性、耐热性能和内部结构。结果 当GMS的−OH的摩尔分数为25%时薄膜综合性能最佳,此时膜的抗拉强度为(9.37±1.28)MPa,弹性模量为(250.55±34.05)MPa,薄膜的吸水率降低到12%,薄膜的水接触角为92°。GMS的加入,增加了薄膜的玻璃态转化温度和铅笔硬度,但热稳定性有所下降。结论 GMS的加入增强了蓖麻油基水性聚氨酯的耐水、耐热和力学性能。     

APTES改性微晶纤维素对淀粉复合薄膜性能影响

目的 探究3-氨丙基三乙氧基硅烷（3-AminopropylTriethoxysilane,APTES）改性微晶纤维素（MicrocrystallineCellulose,MCC）对淀粉基复合薄膜的影响,以期改性得到的硅烷化微晶纤维素（Silanized Microcrystalline Cellulose, MMCC）能够提高淀粉基薄膜的性能。方法 在90℃下糊化淀粉后加入MCC或MMCC,以溶液浇铸法制备淀粉基复合薄膜,采用扫描电子显微镜（SEM）、热重分析（TGA）等测试手段对复合薄膜进行表观形貌和热性能分析,借助万能材料试验机、接触角测量仪等仪器对薄膜进行力学性能、耐水性能、吸湿性能等分析。结果 以APTES改性MCC后的MMCC(MCC与APTES质量比5∶1)掺入淀粉所制备的薄膜MMCC-2/ST,复合薄膜拉伸强度较原淀粉膜（Native Starch Film, ST）提高了230%,水接触角为106.4°,相较于原淀粉膜（Starch Film, ST）提高了60.8°。结论 通过实验表明,MMCC对淀粉基薄膜的力学性能、耐水性能等有较好提升,从而拓宽了淀粉基薄膜在包装...     

天然纤维素纤维的溶解及成膜性能研究

采用电晕处理方法来活化棉纤维表面,然后用不同浓度(质量分数,后同)配比的NaOH/尿素和NaOH/硫脲,2种溶剂体系来溶解该纤维,通过对纤维素溶解度和纤维素溶液成膜性能的研究,发现电晕处理是一种很好的表面活性处理方法,其处理功率的大小,对纤维素的溶解度和成膜性能有较大影响.另外,NaOH/硫脲溶剂体系的溶解性能更优,其纤维素溶液成膜性能更好.     

聚对苯撑苯并二噁唑原纤化纳米纤维制备技术及结构性能

聚对苯撑苯并二噁唑(PBO)纤维是一种具有多重原纤结构的高分子聚合物。通过机械力作用可以使PBO纤维发生原纤化,制备具有直径小于100 nm的PBO原纤化纳米纤维。文中对PBO纤维发生原纤化的历程及机理进行研究,扫描电镜观察发现PBO纤维的原纤化过程包括:脱除皮层、主干破坏、进一步原纤化等阶段,剥离和劈裂是原纤化的主要方式。经过原纤化处理的PBO纤维,呈现不同尺寸纤维组成的多分散体。打浆度70°SR的PBO原纤化纳米纤维的直径可达到50 nm,其保水值118%,纤维长度分布主要集中在0.3~0.5 mm,比表面积21.89 m~2/g。以PBO原纤化纳米纤维为原料,通过湿法成形方式在抄纸系统上制备的纸基材料力学性能随着原纤化程度增加而增加。     

纳米纤维素修饰的碳纳米纤维制备及其疏水性研究

为拓展碳纳米纤维在环境清洁领域的应用，提高碳纳米纤维的水接触角，改善膜表面的疏水性能，获得疏水性较好的碳纳米纤维薄膜，利用静电纺丝法将纳米纤维素(CNFs)与碳纳米纤维前驱体复合，获得具有低表面能和良好疏水性能的纳米碳纤维/纳米纤维素复合纤维膜。通过对纳米纤维素含量进行调控，经预氧化和碳化处理后得到一系列具有规则三维空间网络结构的复合纤维膜，并探究不同纳米纤维素含量对复合纤维膜疏水性能的影响。结果表明：纳米纤维素修饰复合纤维膜随着碳化程度的提高其表面能呈现逐渐降低的趋势，其对水的接触角也逐渐增大，疏水效果得到较大幅度提升。随着纳米纤维素含量继续增加，复合纤维膜的水接触角呈上升趋势，未添加前接触角为36.13°,当纳米纤维素添加质量为20%时，水接触角最大为132.14°,提高了366%。     

蒙脱土与MFC涂层对聚丙烯膜阻隔性能的影响

目的为了提高聚丙烯薄膜的阻隔性,利用涂布的方法研究蒙脱土与微纤化纤维素(MFC)含量对涂布膜阻隔性能的影响。方法以蒙脱土和MFC为主要原料,加入胶黏剂、增稠剂、分散剂制备成涂料,并涂布在双向拉伸聚丙烯薄膜上,以薄膜的氧气透过率、水蒸气透过率、红外光谱分析、XRD分析和热稳定性分析作为评判标准,对薄膜性能进行表征与分析。结果在添加的蒙脱土质量分数为2%,MFC质量分数为0.5%时,双组分涂布膜的氧气透过系数达到最低,较聚丙烯薄膜氧气透过系数下降了97%,水蒸气透过系数在添加蒙脱土质量分数为2%,MFC质量分数为0.3%时达到最低,较聚丙烯薄膜水蒸气透过系数下降了22%,XRD显示当MFC质量分数为0.5%时,插层结构最优,通过热稳定性分析得出,双组分涂布膜在蒙脱土质量分数为2%,MFC质量分数为0.5%时热稳定性最好。结论通过综合分析得出,涂布蒙脱土与MFC双组分涂层可有效提高聚丙烯薄膜的阻隔性能。     

Structural and thermal characterization of Moroccan sugar cane bagasse cellulose fibers and their applications as a reinforcing agent in low density polyethylene

Cellulose fibers were isolated from Moroccan sugar cane bagasse by using three distinct stages. Firstly bagasse was subjected to (1) a hot water (70 °C) treatment to eliminate hemicellulose, then to (2) an alkaline aqueous solution (15% of sodium hydroxide (NaOH), 98 °C) treatment to eliminate lignin, and finally to (3) a bleaching stage. Sugar cane bagasse cellulose fibers were analyzed by different complementary analysis (FT-IR; ¹³C NMR and TG). The reinforcing capability of cellulose fibers extracted from sugar cane bagasse was investigated using low density polyethylene as matrix. The cellulosic preparations were free of bound lignin. The intrinsic viscosity, the viscosity average and the molecular weight were respectively 511 ml/g, 1769 and 286578 g/mol. An enhance on mechanical properties of composites was found, a gain of 72% in Young’s modulus at 25 wt.% fiber loading and a gain of 85% in flexural modulus at 25 wt.% fiber loading, as a results of a good interface adhesion between cellulose fibers and matrix.     

Investigation of physical,chemical and mechanical properties of raw and alkali treated Borassus fruit fiber

The natural fibers nowadays play a major role as reinforcement in composites due to their important properties like lightweight, biodegradability and non-toxicity. Borassus fruit fiber is one such type possessing high cellulose which is inexpensive and available in plenty. The Borassus fruit fibers were extracted and its physical, chemical and mechanical properties such as density, diameter, cellulose, hemicellulose, lignin, wax, denier, tenacity and tensile force were experimentally determined. In this study, the Borassus fruit fibers were treated with 5%, 10% and 15% NaOH and the effect of alkali treatments on the fiber properties were explored. It is interesting to note that 5% NaOH treatment yielded significant improvement in tensile properties of the fibers than the others. The Fourier Transform Infrared Spectrometry (FT-IR) analysis was made to identify the chemical compounds of the raw and alkali treated fibers. The morphological study on raw and alkali treated fibers by Scanning Electron Microscope (SEM) revealed the existence of the impurities on the raw fiber surface and the removal of the same on the treated fibers.     

Investigation of physical,chemical and mechanical properties of raw and alkali treated Borassus fruit fiber

The natural fibers nowadays play a major role as reinforcement in composites due to their important properties like lightweight, biodegradability and non-toxicity. Borassus fruit fiber is one such type possessing high cellulose which is inexpensive and available in plenty. The Borassus fruit fibers were extracted and its physical, chemical and mechanical properties such as density, diameter, cellulose, hemicellulose, lignin, wax, denier, tenacity and tensile force were experimentally determined. In this study, the Borassus fruit fibers were treated with 5%, 10% and 15% NaOH and the effect of alkali treatments on the fiber properties were explored. It is interesting to note that 5% NaOH treatment yielded significant improvement in tensile properties of the fibers than the others. The Fourier Transform Infrared Spectrometry (FT-IR) analysis was made to identify the chemical compounds of the raw and alkali treated fibers. The morphological study on raw and alkali treated fibers by Scanning Electron Microscope (SEM) revealed the existence of the impurities on the raw fiber surface and the removal of the same on the treated fibers.     

高透明羧甲基纤维素/纤维素纤维复合薄膜的制备及其力学性能

针对传统电子器件衬底柔韧性差、不可生物降解的问题,研究了以羧甲基纤维素（CMC）和纤维素纤维为原料,结合抄纸和浸渍工艺,制备在柔性电子器件领域具有潜在应用的高透明CMC/纤维素纤维复合薄膜衬底。分别探究了CMC与北木纤维的配比和CMC分子量对薄膜透明度和力学性能的影响。研究了纤维素纤维的种类（北木、桉木、马尼拉麻和蔗渣纤维）对高透明CMC/纤维素纤维复合薄膜力学性能的影响。结果表明：CMC与北木纤维质量比为7∶3、CMC分子量为700 000时,所制备CMC/北木纤维复合薄膜的透明度为90%,拉伸强度约为111 MPa,耐折度达到2 526次。这种可生物降解、高柔韧性、高强度和高透明的CMC/纤维素纤维复合薄膜有望作为衬底用于构建下一代绿色、柔性电子器件,促进人类社会的可持续发展。     

甘蔗渣显微结构对聚乳酸/甘蔗渣复合材料结构与性能的影响

采用碱处理、硅烷偶联剂处理以及碱处理配合硅烷偶联剂处理等方式改性甘蔗渣(BF),采用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、热重分析(TGA)以及力学性能测试等研究改性后BF结构的变化。结果表明,不同改性方法均明显改变了BF的结构及改性剂的键合方式。碱处理能够去除BF中的半纤维素等小分子聚合物以及部分非晶区的纤维素,导致BF热稳定性降低,结晶度上升。碱液浓度偏高以及碱处理时间过长会导致BF的纤维表面原纤化,虽然能增加与偶联剂反应的面积,但BF的强度大大下降,不利于BF的增强作用。因此,硅烷偶联剂处理的BF/PLA复合材料的相容性及力学性能最佳,其次为碱处理配合硅烷偶联剂处理的BF/PLA复合材料,最后为碱处理的BF/PLA复合材料。     

聚乳酸/茶多酚复合包装膜的制备及性能

目的 对比不同制备方法对复合包装膜性能的影响,以获取具有优良保鲜性能的食品包装膜及其制备方法.方法 以可降解生物材料聚乳酸(PLA)为基材,掺杂茶多酚(TP)活性物质,分别采用静电纺丝法和流延法制备不同质量比的PLA/TP复合包装膜,通过扫描电镜、接触角测试、溶胀性测试、水蒸气透过性测试及抗氧化性测试分析薄膜的形貌和理化性能,并对2种方法制备的复合膜的TP释放行为和草莓保鲜性能进行对比分析.结果 流延膜呈致密多孔结构,纺丝膜呈多层纳米纤维叠加结构;2种复合膜的接触角均随TP质量分数的增加而减小,当TP质量分数从0％增加至20％时,流延膜的接触角从62.70°±3.09°减小至44.08°±2.24°,呈亲水性,纺丝膜的接触角从124.39°±1.69°减小至112.90°±2.42°,呈疏水性,且流延膜的水蒸气透过量随TP质量分数增加而增大,当TP质量分数为20％时,水蒸气透过量增大至(396.93±16.36)g/(m2·d);纺丝膜的溶胀性远高于流延膜,当TP质量分数为20％时,纺丝膜的溶胀率高达347.63°±5.36°,流延膜的溶胀率仅为13.36°±0.56°;随着TP质量分数增加,流延膜和纺丝膜的1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率均逐渐提高,最高分别达(89.76±1.4)％和(97.26±1.25)％;2种膜中TP的释放行为均符合先快后慢的规律,且随着TP质量分数增加而增大,不同流延膜在720 h后累积释放百分比范围为50％～85％,纺丝膜在240 h后基本释放完全,累积释放百分比为75％～95％;流延膜比纺丝膜对草莓的保鲜效果更优,分别将草莓的货架寿命延长至18 d和9 d.结论 流延法制备的复合膜具有亲水性、高水蒸气透过性、高抗氧化性能和优异缓释性能,能有效延长草莓的货架寿命至18 d;纺丝膜制备的复合膜具有疏水性、高溶胀率、优异抗氧化性能,但释放速率快,能有效延长草莓的货架寿命至9 d.     

The effect of surface modifications on sisal fiber properties and sisal/poly (lactic acid) interface adhesion

The main aims of this work were to study the effect of surface modifications on sisal fiber properties as well as on fiber/poly (lactic acid) (PLA) interface adhesion. For this purpose, alkali, silane and combination of both treatments were applied to sisal fiber. The effects of treatments on fiber thermal stability, fiber wettability, morphology, tensile properties and on fiber/PLA interfacial shear strength (IFSS) were studied. After treatments IFSS values improved at least 120%, however, tensile strength of sisal fibers decreased. Alkali treatment removed some non-cellulosic components (hemicelluloses, lignin) as confirmed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The removal of non-cellulosic materials led to fibrillated and rough morphology as observed by optical microscopy (OM). FTIR spectrum of silane treated fibers showed a band related to silane amino group and contact angle measurements confirmed that fibers became more hydrophobic. All treatments used improved fiber/PLA adhesion.     

PBAT/PVA复合涂布膜阻隔性研究

目的 为改善PBAT膜的阻隔性,通过以戊二酸为交联剂改性PVA制备涂膜液,利用涂布法制备了具有高阻隔性的PBAT/PVA复合薄膜。方法 采用红外光谱、差示扫描量热仪、接触角测试仪、水蒸气透过率测试仪等对改性PVA单膜、PBAT/PVA复合膜的结构和性能进行研究。结果 表明由于戊二酸与PVA之间有一定的酯化作用,消耗PVA中部分羟基,从而提高了PVA的耐水性。戊二酸改性提高了PVA膜的疏水性,其接触角从11.3°提高到60.6°。与PBAT纯膜相比,涂覆了戊二酸的PVA涂膜液改性3 h后复合膜水蒸气透过率由647.95 g/(m².24 h)降低到132.07 g/(m².24 h)、氧气透过量由17 730.3 cm³/ (m².d.MPa)降低到396.6 cm³/(m².d.MPa),证明改性3 h的PVA涂膜液对增加PBAT阻隔性最有帮助。结论 利用涂布法制备的PBAT/PVA复合薄膜具有较高阻隔性,为PBAT的广泛应用打下了基础。     

Wettability property of CNT-graphene like film deposited by microwave plasma enhanced vapor deposition technique

Wettability property of carbon nano-tubes (CNT)-graphene like films have been investigated. In this work, we have studied the wettability of CNT-graphene like film deposited on Ni substrate by Microwave Plasma Enhanced vapor deposition Technique (MWPECVD). Compared to the water contact angles of 77.8° for bare Ni substrate, the water contact angle of the CNT-graphene like hybrid films is found to be 128.4°. The nanostructures have been deposited at fixed pressure of 20?Torr with different temperature of 500, 600 and 700?°C. The results indicate that wettability properties of nano-structure can be tailored, significantly. The solid surface energy (SE) of composite films was estimated using contact angle measurements. The wettability of CNT-graphene has been studied first time in film form.     

双分子层液膜法制备纤维素水基泡沫及其稳定性的研究

目的 解决纤维素基泡沫制备过程烦琐、湿泡沫的稳定性差的问题。方法 通过单因素试验,考察了十四醇（TDA）、阿拉伯胶（GAC）质量浓度对双膜气泡的稳定性的影响,在此基础上,采用泡沫成形法制备纤维素水基湿泡沫,通过探究合适的十二烷基硫酸钠（SDS）质量浓度、蔗渣原纤浆质量浓度和搅拌速率进一步提高纤维素水基湿泡沫的稳定性。结果 TDA和GAC质量浓度分别为0.015 g/mL和0.010g/mL时是制备双膜气泡的最佳条件。当SDS质量浓度为0.015g/mL、蔗渣原纤浆（BF）质量分数为1.8%、搅拌速率为2 000 r/min时,纤维素水基湿泡沫稳定性达到最佳。结论 构建了稳定的纤维素水基泡沫,为纤维素基泡沫提供了一种简单、可行的方法。