聚乳酸切片的纺丝工艺研究

以聚乳酸切片为原料,通过熔融纺丝—拉伸两步法制得聚乳酸纤维,研究纺丝温度、纺丝速度、拉伸倍数对聚乳酸纤维性能的影响。结果表明,聚乳酸有良好的成纤能力,纺丝速度、纺丝温度的变化对聚乳酸纤维的相对分子质量均有显著影响。     

聚乳酸纤维及其应用

简单介绍了聚乳酸的聚合方法和目前聚合工艺方面的新发展。介绍了聚乳酸纤维的纺丝方法、聚乳酸熔融纺丝工艺流程及目前国内外聚乳酸纤维的生产、开发情况。比较了聚乳酸纤维与涤纶等合成纤维及真丝等天然纤维的物理性能指标。最后,介绍了聚乳酸纤维在医药、织物和非织造布方面的应用。     

高性能聚乳酸纤维的研究进展

介绍了高强度、可控降解周期的聚乳酸及其共聚物、共混物纤维的成型方法和纤维的应用情况;阐述了熔融纺丝、溶液纺丝、静电纺丝、超临界流体法、凝胶冻干等纤维成型方法的特点;评价了成型工艺对纤维形态结构和性能的影响、研究聚乳酸纤维的新方法、新成果以及高性能聚乳酸纤维在生物医学领域、日用工业等领域的应用前景。     

PVP/PLA乳液静电纺丝成形及纤维毡亲水性能研究

利用乳液静电纺丝可制备一定复合结构的共混纤维,且可通过调控乳液的组成而实现聚合物溶液在低浓度下的静电纺丝成形。以聚乙烯基吡咯烷酮(PVP)水溶液为分散相,聚乳酸(PLA)氯仿溶液为基体相,制备不同水相比例的PVP/PLA乳液,研究了PVP/PLA乳液静电纺丝成形及其纤维毡的亲水性能。结果表明:乳液体系中PVP水相的加入可使PLA乳液在远低于其单独可纺溶液浓度下纺丝成形,所得纳米纤维随着PVP水相比例的提高而表现出纤维直径增加,并发生纤维集结成束,PVP大部分分布在复合纤维毡的表层,纤维毡呈现明显的透水性能;PVP的加入可有效改善PLA纳米纤维毡的亲水性能。     

聚乳酸纤维的静电纺缝及其形态结构研究

采用二氯甲烷为溶剂，以滚筒为收集装置，利用静电纺丝法制备了聚乳酸纳米纤维。分析了溶液体系和滚筒转速对纤维形态结构的影响。结果表明：在质量分数相同的条件下，采用相对分子质量较大的聚乳酸切片所纺纤维直径细而均匀；质量分数增加时，电纺丝产品由一些高分子捌纳米液滴渐变为成形较好、珠状较少的平滑纤维，其平均纤维直径先增加后减小；控制收集滚筒的转速在一定范围内，可以获得排列取向较好的纤维。     

聚乳酸纤维的静电纺丝及其形态结构研究

采用二氯甲烷为溶剂,以滚筒为收集装置,利用静电纺丝法制备了聚乳酸纳米纤维。分析了溶液体系和滚筒转速对纤维形态结构的影响。结果表明:在质量分数相同的条件下,采用相对分子质量较大的聚乳酸切片所纺纤维直径细而均匀;质量分数增加时,电纺丝产品由一些高分子微/纳米液滴渐变为成形较好、珠状较少的平滑纤维,其平均纤维直径先增加后减小;控制收集滚筒的转速在一定范围内,可以获得排列取向较好的纤维。     

甲壳质类纤维的制备

介绍了甲壳质纤维的原料、纺丝原液制备、纺丝成形和后处理的方法及品质指标。以甲壳质衍生物制备纺丝质液，进行干法或湿法纺丝，而获得甲壳质纤维，纤维的卫生性能优良。     

添加共混方式对共混纤维成形及结构的影响

聚合物共混改性是制备功能材料最常用的方法，而对于纤维纺丝成形而言，直接共混和母粒添加共混的差异性未见有报道。以尼龙6为原材料，聚酯类添加剂为功能性共混物，分别研究了直接共混和母粒添加共混对纤维成形，共混纤维的物性的比较，结果发现，共混母粒纺丝成形所得共混纤维的机械性能优于直接共混纺丝成形共混纤维，且后处理效果优于直接共混纺丝成形，在添加的改性剂质量分数达30％以上时，后处理共混纤维的表面存在一定微细纤维结构，共混母粒纺丝成形所得共混纤维处理后纤维表面的微细纤维结构更为细小和均匀。     

电子纺丝成形及纤维形态结构研究

电子纺丝是—种可能制备具有微细直径的纤维成形技术，本文介绍了电子纺丝技术的基本原理和电子纺丝成形工艺对纤维形态结构的影响以及电子纺纤维的应用前景等。     

聚乳酸及其共聚物纤维的制备及应用

主要介绍了聚乳酸及其共聚物的纺丝方法,以及该聚合物及纤维的性能及主要用途     

不同聚乳酸切片的流变性能比较及其对熔融纺丝性能的影响研究

利用毛细管流变仪对四种不同聚乳酸切片的流变行为进行了对比分析,并探讨了流变性能差异对熔融纺丝性能的影响。结果表明:四种聚乳酸熔体均呈现剪切变稀现象,具有非牛顿流体的流动特征;随着温度升高,聚乳酸熔体的非牛顿指数n增大;四种聚乳酸熔体的粘流活化能E_η较小,粘度随温度的变化小,有利于纺丝成型;四种聚乳酸熔体的结构粘度指数△η介于0.8~1.4,可纺性和稳定性较好。     

Solution blow spinning: A new method to produce micro‐ and nanofibers from polymer solutions

A solution blow spinning technique was developed using elements of both electrospinning and melt blowing technologies as an alternative method for making non‐woven webs of micro‐ and nanofibers with diameters comparable with those made by the electrospinning process with the advantage of having a fiber production rate (measured by the polymer injection rate) several times higher. The diameters of fibers produced ranged from 40 nm for poly(lactic acid) to several micrometers for poly(methyl methacrylate). This solution blow spinning method uses a syringe pump to deliver a polymer solution to an apparatus consisting of concentric nozzles whereby the polymer solution is pumped through the inner nozzle while a constant, high velocity gas flow is sustained through the outer nozzle. Analysis of the process showed that pressure difference and shearing at the gas/solution interface jettisoned multiple strands of polymer solution towards a collector. During flight, the solvent component of the strands rapidly evaporates forming a web of micro and nanofibers. The effect of injection rate, gas flow pressure, polymer concentration, working distance, and protrusion distance of the inner nozzle was investigated. Polymer type and concentration had a greater effect on fiber diameter than the other parameters tested. Injection rate, gas flow pressure, and working distance affected fiber production rate and/or fiber morphology. Fibers were easily formed into yarns of micro‐ and nanofibers or non‐woven films that could be applied directly onto biological tissue or collected in sheets on a rotating drum. Indeed, virtually any type of target could be used for fiber collection. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation of poly(lactic acid) fiber by dry–jet–wet spinning. II. Effect of process parameters on fiber properties

The dry–jet–wet spinning process was employed to spin poly(lactic acid)(PLA) fiber by the phase inversion technique using chloroform and methanol as solvent and nonsolvent, respectively, for PLA. The as spun fiber was subjected to two‐stage hot drawing to study the effect of various process parameters, such as take‐up speed, drawing temperature, and heat‐setting temperature on the fiber structural properties. The take‐up speed had a pronounced influence on the maximum draw ratio of the fiber. The optimum drawing temperature was observed to be 90°C to get a fiber with the tenacity of 0.6 GPa for the draw ratio of 8. The heat‐setting temperature had a pronounced effect on fiber properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3774–3780, 2006     

Solution blow spun titania nanofibers from solutions of high inorganic/organic precursor ratio

In this work titania nanofibers were produced from different precursor solutions by solution blow spinning. Hydrophilic polyvinylpyrrolidone, hydrophobic poly(vinyl acetate) and amorphous and semi-crystalline poly(lactic acid) polymers were used with green-solvents and titanium isopropoxide as the inorganic precursor. Hybrid nanofibers with high inorganic loading content were successfully produced from all precursor solutions. The fibers were calcined at different annealing temperatures for evaluation of phase transitions. The minimum temperature to obtain pure titania fiber was found to be 500 °C, as assessed by thermal characterization. Anatase was the unique polymorph formed at this annealing temperature. This is of paramount importance due to its photocatalytic character. Calcination at high temperatures showed that rutile slightly appeared at 600 °C for the polyvinylpyrrolidone-based system and showed a strong peak at 700 °C for all systems, co-existing with anatase as minor phase. The use of amorphous and semicrystalline poly(lactic acid) polymers did not influence the anatase crystal size and phase conversion. This was found to be dependent on the annealing temperature and medium acidity, as currently found in powder synthesis.     

Green Engineered Polypropylene Biodegradable Fibers Through Blending with Recycled Poly(lactic) Acid Plastic Wastes

The modification of polypropylene (PP) fibers via blending with recycled poly(lactic) acid (r-PLA) flakes by a melt spinning method was investigated. Mechanical and morphological properties, biodegradability, differential scanning calorimetery (DSC) analysis, and dyeing behavior were carried out for physical and structural characterization of the fiber samples. The results showed that the PP/r-PLA blend fibers with the different blend ratios could be successfully melt spun along with suitable continuity. Acceptable tenacity and initial modulus and suitable biodegradability were obtained for the modified PP fibers. Dye uptake of the modified PP fiber samples was improved and the washing and light fastness of some them were excellent.     

PBO的合成及其纺丝技术研究进展

概述了聚对苯撑苯并二(?)唑(PBO)及PBO纤维国内外的发展现状;详述了PBO的合成方法:对苯二甲酸法、对苯二甲酰氯法、三甲基硅烷基化法、对苯二甲酸盐法、对羟基苯甲酸酯法等,以及PBO纤维的制备:液晶纺丝法和静电纺丝法;建议今后国内PBO纤维的发展应开发具有自主知识产权的高性能PBO纤维生产技术。     

Effect of solution concentration in microfiltration properties of PLA mats produced by solution blow spinning

In order to remediate the difficulty of access to safe drinking water by 1/3 of the world population, mats produced by solution blow spinning (SBS) have a great potential for use in liquid filtration due to their small pores and high porosity, being capable of filtrating water by retaining particles and even microorganisms. In this context, this work aims the production and characterization of poly (lactic acid) mat obtained by SBS to be morphologically, thermally, and mechanically evaluated, as well as to observe water flux properties. The correlation between structure-processing-properties is an important part of the work, which shows that lower concentration of polymeric solution leads to mats with smaller average fiber diameter, greater crystallinity, impacting on their greater tensile strength. The water flux performance shows that mats obtained from higher polymer concentration solutions present less resistance to the water flow, which indicates larger pore diameters.     

后处理对PLLA/PDLA共混纤维结构和性能的影响

采用聚L-乳酸(PLLA)与聚D-乳酸(PDLA)共混熔融纺丝,初步研究了后处理条件对纤维结构与性能的影响。结果表明:通过PDLA与PLLA的共混熔融纺丝,形成了立体复合型PLA晶体(sc-PLA);随着热处理温度的提高,纤维中sc-PLA晶体的含量增加,纤维力学性能下降;拉伸温度为75℃时所得纤维的力学性能最好,随着拉伸倍数的增加,纤维力学性能提高,纤维中sc-PLA晶体的含量变化不大。     

Water-born 3D nanofiber mats using cost-effective centrifugal spinning: comparison with electrospinning process: A complex study

A comparison of the electrostatic and centrifugal spinning of poly(vinyl alcohol) and poly(vinyl pyrrolidone) is shown in terms of the resulting fiber morphology and the process conditions. Specific parameters of centrifugal spinning, such rotational speed of spinneret and the relative humidity, were extensively investigated in details. Morphologies and diameters of resulting fiber mats were investigated by a scanning electron microscopy and compared between the two spinning techniques. The results revealed that formation of fibers is mainly affected by the initial polymer concentrations (and resulting viscosities) of polymeric solutions, which is in line with previous reports. However, the key novel finding of this work is that increasing relative humidity during centrifugal spinning process leads to greatly reduced fiber diameters to the levels typical for electrospinning. The obtained comparison is discussed and clearly shows technological advantages of the centrifugal spinning over electrospinning, enabling quantitative production of fibers with same or similar diameters.     

PBT/PEG/LA可降解聚醚酯的合成及纺丝研究

采用对苯二甲酸二甲酯(DNT)、1,4-丁二醇(BDO)、聚乙二醇(PEG)和乳酸(LA)合成了聚对苯二甲酸丁二醇酯(PBT)/PEG/LA可降解聚醚酯,通过纺丝制备了PBT/PEG/LA共聚物纤维。结果表明:红外光谱和核磁共振分析所得聚合物为PBT/PEG/LA。PBT/PEG/LA共聚物在50℃真空预干燥5 h,80℃干燥5 h,控制纺丝温度高于聚醚酯熔点15～30℃可顺利纺丝,纤维质量良好。随着拉伸倍数、热定型温度或时间的增加,纤维的断裂强度提高.断裂伸长率下降。LA摩尔分数高,有利于纤维降解,但纤维熔点和断裂强度相应下降。