PMMA／PBT共混体系可纺性及纤维的结构与性能

研究了PMMA／PBT共混纤维的可纺性和拉伸性，并测定了拉伸丝的力学性能、取向和结晶结构。结果表明，PMMA的加入可以延迟PET的成形，减小纤维的取向，提高PMMA／PBT卷绕丝的断裂伸长，从而提高纤维的后拉伸倍数，提高纤维的生产效率；PMMA的加入量在5％以下时，不影响纤维的可纺性；PMMA／PBT共混纤维拉伸丝的强度和断裂伸长可达到常规PET纤维的要求；扫描电镜照片显示，PMMA以棒状形式分散在PET基体中，分散直径为1μm左右。     

PC/PET共混物流变性及可纺性

用熔融共混法制得一系列PC/PET共混物,通过Instron流变仪,小型纺丝机,差示扫描量热,广角X光衍射和热收缩等实验对PC/PET共混体系的流变性及可纺性进行研究。讨论了PC含量对流变参数及可纺性的影响。结果表明,PC/PET共混熔体属切力变稀流体,在PC含量小于15%(mol比)时有较好的可纺性及纤维力学性能,PC/PET共混拉伸丝是一种高收缩纤维。     

玉石粉/PET共混切片流变性能及可纺性研究

将聚对苯二甲酸乙二醇酯(PET)和玉石粉按一定质量比例共混熔融,制备出含玉石粉质量分数为0~1.8%的玉石粉/PET共混切片(简称共混切片)。分析了玉石粉含量对共混切片的流变性能、可纺性及玉石粉/PET预取向丝(POY)力学性能的影响。结果表明:随剪切速率的增加,共混切片黏度下降,其熔体为切力变稀流体;在相同剪切速率下,随着玉石粉含量增加,共混切片表观黏度变小,提高熔体温度,共混切片表观黏度变小;纺丝过程中,玉石粉质量分数超过1%时,断头现象增加;采用合适的喷丝孔孔径,有利于改善熔体的可纺性;随着玉石粉含量增加,纤维断裂强度和断裂伸长率都显著减少。     

热致性液晶共聚酯-PET共混体的可纺性及纤维的性能

通过流变性能、表面张力等的测试对 PHB/PET(60/40)共聚酯与 PET 共混体的可纺性及加工条件进行了讨论。用改制的熔融指数仪纺制了不同配比的共混纤维,并测定了初生纤维及拉伸丝的力学性能,通过偏光显微镜、扫描电镜、DSC 测定了纤维结构。共混体在300℃熔融,280℃纺丝,当共聚酯含量在6.6%以下时,共混体有较好的可纺性。共聚酯含量在3.3%时,纤维有较好的强度与模量,与同等条件下纺制的纯 PET 纤维相比,强度提高70%,模量可提高两倍多。     

聚酯/多壁碳纳米管复合导电纤维的制备及性能

以羧基化多壁碳纳米管(MWNT-COOH)为导电填料,采用双螺杆熔融挤出制备聚酯(PET)/MWNT-COOH共混切片,通过熔融纺丝得到PET/MWNT-COOH复合纤维。研究了MWNT-COOH含量和拉伸处理对复合纤维可纺性、导电性能、力学性能和表面形貌等的影响。结果表明:当MWNT-COOH质量分数小于1.0%时,切片具有较好的可纺性,初生纤维的导电逾渗阈值为0.5%~1.0%;MWNT-COOH的加入提高了纤维的断裂强度,当MWNT-COOH质量分数为0.1%时,纤维断裂强度提高约34%,随着MWNT-COOH含量增加,纤维断裂强度的增加幅度逐渐下降;拉伸会使MWNT-COOH沿纤维轴向取向,有利于MWNTCOOH间的互相搭接形成导电通路,提高纤维的导电性能。     

PA6/PET共混熔体流变性能和成丝过程的研究

本文对PA6/PET共混物的流变性能及其对可纺性的影响进行了研究。结果表明:共混熔体的非牛顿指数减小,弹性明显增大,因此,PA6与PET共混后可纺性下降。经再造粒虽对其可纺性有所改善,但成丝的性能变差。纺丝时在纺程上部必须设保温缓冷段才能纺丝。拉伸工艺对纤维的结构和性能影响很大。随PET含量的提高,共混纤维的强度下降,抗张模量增大。     

PET—PBT共混物可纺性和共混纤维结构与性能的研究

本文主要研究了两部分内容。一是关于PET-PBT共混物的流变性能,并据此预见了共混体系的可纺性,结果表明,当PET中加入PBT后,熔体的弹性有所增大,但变化不大,因此可纺性变化不大;二是关于初生纤维和拉伸纤维的结构和性能,主要讨论了共混纤维的结构形态,力学性能,染色性,回弹性,拉伸行为以及加工性能等。     

PET-PEO-DSAS三元共混体系改性涤纶的可纺性及抗静电性能研究

在PET中除加入PEO(聚氧化乙烯)以外,还添加了离子型表面活性剂烷基笨磺酸钠(DSAS)进行三元共混纺丝。由于高吸湿性PEO组分与离子型DSAS组分的协同作用,使纤维上积蓄的电荷活化,所制得的改性PET纤维的抗静电性能有了明显提高。实验结果表明:选用PEO分子量为20000、添加量为1.5wt％;DSAS添加量为1.0wt％。的PET—PEO—DSAS三元共混体系,其可纺性及拉伸性能为最好,所得丝条的质量与纯PET大体相同,而且这种共混纤维的抗静电改性效果及耐洗涤性也最佳。     

石墨烯改性PET纤维的制备及其抗静电性能研究

采用共混改性的方法,先以石墨烯粉体与聚对苯二甲酸乙二醇酯(PET)共混挤出制备石墨烯母粒,再以石墨烯母粒和PET切片共混纺丝制备石墨烯改性PET纤维,研究了石墨烯粉体在石墨烯母粒中的过滤性,以及石墨烯添加量对改性PET纤维的机械性能、取向度以及抗静电性能的影响。结果表明:石墨烯粉体在母粒中质量分数为5.0%时具有较好的过滤性能;石墨烯的引入会降低PET纤维的强度,但随着石墨烯粉体添加量的增加,可以增强改性PET纤维的力学性能,同时可以提高纤维的整体取向性和抗静电性能,且拉伸倍数的增加也可以有效地提升改性PET纤维的抗静电性能;在石墨烯粉体质量分数为1.0%、纤维经3.8倍拉伸时,石墨烯改性PET纤维的断裂强度为2.8 cN/dtex,断裂伸长率为46.2%,取向因子为0.92,体积比电阻为3.29×10~7Ω·cm。     

PET-PEG嵌段共聚物纤维和PET/PET-PEG共混纤维的吸湿性和抗静电性能研究

本文对PET-PEG嵌段共聚物的可纺性、PET-PEG纤维和PET/PET-PEG共混纤维的吸湿性和抗静电性能进行了研究,探讨了共混纤维的抗静电机理。发现随PEG含量的增加,PET-PEG嵌段共聚物的可纺性变差,但纤维的吸湿性和抗静电性能提高,抗静电耐久性变差。PEG在PET-PEG纤维和PET/PET-PEG共混纤维中的导电机理为质子导电。PEG含量为30wt％(占 TPA)的PET-PEG嵌段共聚物与PET的共混纤维具有工业化前途。     

聚酯——聚乙烯共混纤维研究

探讨了PET与不同分子量的高密度聚乙烯和低密度聚乙烯共混体的流变性能、可纺性以及共混纤维的形态结构与性能。结果表明,[η]=0.65的PET与[MI]=6.9的HDPE的共混体的可纺性较好,纺成的纤维具有以PE为海、PET为岛的海—岛型形态结构,经90℃拉伸5倍和100℃热处理后,PE高度结晶,而其中的PET仍处于非晶态。这样的纤维具有较好的力学性能,制成的非织布试样在140℃进行处理,PE皮层发生熔融粘接,PET微纤发生结晶,控制收缩,保持纤维形态。     

PET/PHA共混纺丝研究

通过差示扫描量热(DSC)分析、X射线衍射和应力-应变分析对聚对苯二甲酸乙二醇酯(PET)与聚羟基脂肪酸酯(PHA)共混纤维的结晶、取向及力学性能进行测试,考察了共混体系的可纺性.结果表明:随着PHA添加量的增大,共混体系的可纺性下降.添加PHA质量分数小于2.5%时,可纺性良好,添加PHA质量分数小于1.5%时,PH...     

傅里叶变换显微红外光谱技术在涤纶中的应用

利用傅里叶变换红外光谱仪和红外显微镜测定了涤纶(PET)的未完全拉伸丝(UDY)、预取向丝(POY)、完全拉伸丝(FDY)的红外光谱,测定了3种纤维的取向度、结晶度。结果表明:傅里叶变换显微红外光谱技术可以方便的测定PET单纤维的红外光谱,且从峰的偏移可以判断结晶带的变化;PET纤维随着拉伸倍数的提高,其取向度和结晶度都相应提高。     

导电纤维的研究开发——第Ⅳ报海-岛结构导电纤维的制备

用Cul(含量<25％)、聚醚(PEO)及烷基苯磺酸钠(SDBS)组成的导电共混物与PET熔融混纺,制备了白色导电纤维,研究了纤维的可纺性、拉伸性、力学性能、耐洗性及导电性。发现所得导电纤维是以PET为海,导电共混物为岛的“海-岛”结构,岛相呈细长,连续的网络分布,其形态结构和性质对纤维性能影响极大。     

miPP与ziPP的可纺性比较

采用熔融纺丝法 ,比较了茂金属催化聚丙烯 ( mi PP)和齐格勒 -纳塔催化聚丙烯 ( zi PP)切片在相同纺丝条件下的可纺性 ,研究了纺丝条件对其初生纤维结构与性能的影响。研究发现 ,mi PP的可纺性受温度的影响比较大 ,在低温下纺丝性能较好 ;mi PP卷绕丝与 zi PP卷绕丝相比具有良好的可拉伸性能 ;m i PP的相对分子质量分布较窄 ,其初生纤维的取向度较高     

PET卷绕丝预取向对后加工拉伸性能和纤维结构、性能的影响

应用ＷＡＸＤ、ＤＳＣ、声速法、密度法、双折射等，讨论了在提高卷绕丝纺速与喷丝头拉伸比后，纤维的预取向增大，对其在后加工中的拉伸性能及其结构、性能的影响。结果表明，预取向高的卷绕丝，在后加工一道拉伸过程中，除了非晶取向外，还产生了“应变结晶”（取向诱导结晶）。由此造成晶态、取向非晶态结构差异大，而导致强度、伸长不匀率上升，产生毛丝、缠辊，但可得到高强度纤维。调整拉伸浴槽温度、拉伸速度，可改变卷绕丝的拉伸性能。     

Correlation between tensile properties and network draw ratio for poly(ethylene terephthalate) fibers with wide range of molecular orientation and crystallinity

Poly(ethylene terephthalate) (PET) fibers with wide range of molecular orientation and crystallinity were prepared by the cold drawing of melt-spun yarns in a temperature-controlled water bath and the subsequent annealing for these samples. For all samples, the true stress-strain curves can be principally superimposed to a master curve which corresponds to the stress-strain curve for the original nonoriented amorphous yarn and it was confirmed that the original (intrinsic) network structure is not affected by molecular orientation and crystallinity significantly. Tensile properties of these fibers were studied systematically in terms of the network draw ratio which was determined as a shift factor in the matching process of a true stress-strain curve to the master curve. Consideration of the tensile drawing behavior has shown that the network draw ratio, which is defined as an extension of unique intrinsic network structure, has direct correlation with mechanical properties including the yield and breaking behaviors. When the network draw ratio is taken into consideration, PET fiber, even if it has crystallinity or molecular orientation, has appeared to behave in the manner of an almost ideal rubber during the tensile testing carried out as cold drawing. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2631–2646, 1997     

Processing of thermotropic liquid crystalline polymers and their blends—analysis of melt-spinning TLCP fibers

Isothermal melt-spinning of two thermotropic liquid crystalline polymers (TLCPs), a wholly aromatic copolyester KU-9211 (also named K161 from Bayer AG) and an aliphatic containing TLCP, PET/PHB60 (Tennessee Eastman), was studied to analyze the effect of processing conditions on fiber properties. Fibers were melt-spun from a capillary rheometer equipped with an isothermal chamber in which cross-flowed air was used as the cooling medium. The processing variables studied included the extrusion temperature, the extrusion rate, the cooling conditions, and the draw ratio. As-spun fibers were characterized by measuring storage moduli and molecular orientation parameters as a function of draw ratio under various processing conditions. Among the processing variables studied, the draw ratio was the primary factor in determining both the fiber modulus and the molecular orientation. The extrusion rate did not appear to affect the fiber properties within the range studied. The properties of K161 fibers were also dependent on the extrusion and cooling temperatures, while PET/PHB60 fibers were rather insensitive to the processing temperatures within data scatter and temperatures studied. A composite model based on a rigid-rod rotation mechanism and the deformation of nematic domains in an elongational flow field was used to model the experimental results and was compared with other theories available. Conformance of data to the composite model was obtained by use of a single temperature dependent parameter n, suggesting that the rigid-rod rotation mechanism could be used to predict the orientation development of TLCPs. The Halpin-Tsai equations and the orthotropic equation for angular dependence were used to describe the elastic properties of the TLCP fibers.