PTFE纤维制备技术的研究进展

介绍了聚四氟乙烯(PTFE)纤维的结构和物理化学性能;详述了PTFE纤维制备技术,如载体纺丝(湿法纺丝、干法纺丝)、糊料挤出纺丝、熔体纺丝、切割膜裂法等纺丝工艺,比较了各种纺丝工艺的优缺点,载体纺丝法制备PTFE纤维技术较为成熟,可制备线密度较小的纤维;叙述了PTFE纤维在过滤材料、医学材料、密封填料和纺织工业等方面的应用;指出我国PTFE纤维发展的关键是改进及开发新的制备技术,提高PTFE纤维的质量及产量。     

聚四氟乙烯/聚乙烯醇共混加硼湿法纺丝

以聚乙烯醇(PVA)为载体,利用加硼湿法纺丝法制备了聚四氟乙烯(PTFE)/PVA共混初生纤维。采用扫描电子显微镜对共混初生纤维的形态结构进行了表征,通过Instron5565万能强力仪对单根初生纤维丝条的力学性能进行了测试。结果表明:PTFE/PVA共混纤维丝条的横截面形态为非圆形;PTFE/PVA质量比是湿法纺丝的重要因素,当PTFE/PVA质量比为80/20时,共混纤维丝条的截面较接近圆形,且结构密实,力学性能最好。     

湿法纺丝制备PTFE纤维的后处理工艺研究

以聚乙烯醇(PVA)为载体采用湿法纺丝制备聚四氟乙烯(PTFE)/PVA初生纤维,然后进行烧结、拉伸后处理得到PTFE纤维,考察了烧结温度、烧结时间和拉伸倍数对PTFE纤维力学性能的影响,讨论了强酸和强碱对PTFE纤维的腐蚀作用。结果表明:较佳的后处理工艺是烧结温度380℃,烧结时间30 min,拉伸倍数5,制得的PTFE纤维的线密度为14.60 dtex,断裂强度为0.871cN/dtex,断裂伸长率为261.26%,模量为0.525 cN/dtex;PTFE纤维具有优异的耐酸碱腐蚀性能。     

聚四氟乙烯纤维的制造方法及聚四氟乙烯纤维

本发明提供无需象乳液纺丝法那样使用基质材料就能够制造聚四氟乙烯（PTFE）纤维特别是PTFE长纤维、并且生产率优于包括切膜丝法在内的现有制造方法且能够提高所得纤维的机械特性和直径的自由度的PTFE纤维制造方法。通过在PTFE的熔点以上的温度下对细绳状的含PTFE固形物（第一固形物）进行拉拔加工，使上述第一固形物的直径减小的方法。     

PVA/PTFE浆液中硼酸质量分数对PVA/PTFE纤维性能的影响

实验研究了添加不同质量分数的硼酸凝胶剂对以聚乙烯醇(PVA)为载体,制备干质量比为1∶6的PVA/聚四氟乙烯(PTFE)纤维的纺丝工艺工艺参数和复合初生纤维质量的影响;实验还探讨了将硼酸作为外部凝固浴纺制PVA/PTFE纤维的可行性。结果表明:凝胶剂质量分数多的浆液在其本身最佳的纺制参数条件下纺制出的PVA/PTFE复合纤维的强度较佳;将硼酸作为外部凝固浴纺制具有一定的可行性。     

载体法制备聚四氟乙烯纤维及烧结工艺研究

以载体法制备出聚四氟乙烯纤维(PTFE)/聚乙烯醇(PVA)初生丝,然后对初生丝进行不同时间的烧结,以除去PVA制得PTFE纤维,对PTFE纤维进行不同程度的拉伸,检测不同烧结时间和拉伸倍数对纤维力学性能的影响。     

聚四氟乙烯纤维的制备与性能表征

通过聚乙烯醇(PVA)作为载体,与聚四氟乙烯(PTFE)分散液配成混合溶液进行湿法纺丝制备PTFE/PVA初生纤维,成形后经烧结去除PVA。根据TG/DTG曲线选取烧结温度并判断烧结后样品的PVA去除程度,用扫描电镜观察了初生丝及烧结后纤维的形貌,同时通过强力测试得出烧结后试样的力学性能,结果表明,随着烧结时间的延长,烧结越充分,力学性能越优。     

聚四氟乙烯中空纤维膜的亲水改性及稳定性能

针对聚四氟乙烯(PTFE)的疏水问题,采用两亲性聚合物亲水剂对PTFE中空纤维膜进行亲水改性。两亲性聚合物可能通过疏水链与聚四氟乙烯的原纤及节点发生缠结进而固定在PTFE膜上。研究发现,两亲性聚合物在不影响PTFE中空纤维膜结构的基础上成功地覆盖在PTFE中空纤维膜表面。亲水改性聚四氟乙烯膜(M-PTFE)的水通量随压力的增加而增加,在高压(100 kPa)和负压(-20 kPa)长时间的运行条件下也能保持4 674 L/(m²·h)和1 960 L/(m²·h)的数值。两亲性聚合物改性剂在PTFE膜表面的稳定性为改性PTFE膜稳定的大水通量提拱了理论基础,也为PTFE中空纤维膜在水处理领域的应用提供了有利的技术支撑。     

PTFE/PVA混合浆液挤出胀大性能及复合薄膜结构性能的研究

以聚乙烯醇(PVA)为载体,配制不同质量比的聚四氟乙烯(PTFE)/PVA混合浆液,制备PTFE/PVA复合膜,确定了PTFE/PVA复合膜时的PTFE最大添加量;利用摄影法对PTFE/PVA混合浆液的挤出胀大现象进行了研究。结果表明:载体法制得的PTFE仍具有良好的疏水性能,在PTFE与PVA的质量比为6∶1时,制得的PTFE薄膜的力学性能较好;选用其6∶1的浆液作为纺丝原液,挤出胀大比随着挤出压力的增加而增大,而随着纺丝原液温度的升高、喷丝头长径比的增加以及滤布层数的增加而减小。     

两亲性聚合物沉积法聚四氟乙烯中空纤维膜的亲水改性研究

以具有两亲结构的两亲性聚合物脂肪醇聚氧乙烯醚，通过回旋振荡涂覆法对疏水的聚四氟乙烯(PTFE)中空纤维膜改性处理制备亲水性聚四氟乙烯膜，在膜表面形成亲水沉积层，并研究了两亲性聚合物浓度、涂覆时间、热处理时间和热处理温度对PTFE中空纤维膜亲水性能的影响。结果表明，两亲性聚合物浓度为5%,涂覆时间2 h,热处理时间和温度分别为16 h和40℃条件下制备的聚四氟乙烯中空纤维膜，纯水通量可达2 482 L/(m²·h)。     

聚四氟乙烯可熔融加工研究进展

介绍了聚四氟乙烯(PTFE)的应用情况;阐述了PTFE的可熔融加工方法,包括柱塞冲压式挤出、可熔融加工的PTFE组合物、可熔性PTFE、超临界二氧化碳在PTFE挤出成型中的应用;分析了PTFE可熔融加工的难点;提出了PIFE可熔融加工的研究方向.     

Electrostatic and mechanical properties of extrusion spun PTFE monofilament with integration of microtourmaline particles

This study reports on polytetrafluoroethylene (PTFE) monofilaments prepared by extrusion spinning with the integration of tourmaline particles. The resultant PTFE monofilaments have excellent electrostatic properties and contain different amounts and sizes of tourmaline particles. Tensile tests show that the PTFE monofilaments with 7 wt % and 1 wt % of 5 μm particles possessed tensile strengths of 1175 N and 1026 N, which were 12.5% and 23.6% lower than those of the pure PTFE monofilament, respectively. In electrostatic properties, there was 14.3% growth in surface voltage compared with the original PTFE monofilament in the series of monofilaments with varying content of tourmaline particles. When the particle size was 5 μm, the voltage was 14.7% higher than that of pure PTFE monofilament in the series of monofilaments with varying sizes of tourmaline particles. In addition, a model of electric field distribution around the monofilament was proposed based on a static electricity test. Successful research on such an intriguing monofilament might provide a novel application of the PTFE and tourmaline. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46401.     

Reactive polytetrafluoroethylene/polyamide compounds. I. Characterization of the compound morphology with respect to the functionality of the polytetrafluoroethylene component by microscopic and differential scanning calorimetry studies

Compounds of electron‐beam‐irradiated polytetrafluoroethylene (PTFE) and polyamide (PA) were produced by reactive extrusion. During extrusion, both a breakdown process of the PTFE agglomerates and a chemical reaction between PTFE and PA took place. The morphology of the compounds was characterized with differential scanning calorimetry using fractionated crystallization, with atomic force microscopy and scanning electron microscopy, and with dynamic light scattering. The particle size of the dispersed PTFE phase decreased as the irradiation dose increased. A simple theoretical model of the breakdown process of PTFE agglomerates was made for the discussion of the development of the observed degree of dispersion. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1308–1316, 2005     

Rheology and processing of polytetrafluoroethylene (PTFE) paste

This is a review article on the paste extrusion of polytetrafluoroethylene (PTFE). The article begins with an overall presentation of the process. Important aspects related to this process are the physical properties of PTFE, its rheology, the morphological changes occurring during flow (fibrillation) that play a critical role on the dimensional stability of the final products, the geometrical characteristics, and types of dies used and temperature. PTFE is a compressible, zero Poisson's ratio material, and the mechanical properties of extrudates after extrusion are also discussed in view of fibrillation and Poisson's ratio.     

超高相对分子质量聚乙烯管材新型连续挤出成型技术

超高相对分子质量聚乙烯（PE-UHMW）管材连续挤出成型法有压制-烧结、柱塞推压、单螺杆挤出、双螺杆挤出和柱塞冲压挤出等几种，其中柱塞冲压挤出成型法是新开发的一种PE-UHMW管材连续挤出成型技术，该技术的突出优点表现在：能加工任意相对分子质量的PE-UHMW树脂，加工能力强；能实现连续挤出，生产效率不低于单螺杆挤出法，而制品的表面质量、力学性能（如耐磨性）则优于单螺杆挤出法；完全正位移输送机理，温度控制简单可靠（控温段只有三个），因此加工过程中的降解程度较小，能很好地保持原料固有的优良性能；主机结构简单，能耗低（约为螺杆挤出法的30％～50％），生产线造价便宜。另外，采用该技术还能挤出高质量的聚四氟乙烯（PTVE）和过氧化物交联聚乙烯（PEX-a）制品。     

Effect of polytetrafluoroethylene on the foaming behaviors of linear polypropylene in continuous extrusion

Linear polypropylene (PP) foams, blown in the continuous extrusion process using supercritical CO₂ as the blowing agent, exhibited poor cell morphology and narrow foaming window, because of their low melt strength. In this study, polytetrafluoroethylene (PTFE) was blended with PP resin with the aim of improving the foaming behavior of PP. It was found that the PTFE particles were deformed into fine fibers under shear or extensional flows during the extrusion process, which significantly increased the melt strength of PP from 0.005 N to 0.03 N (PP/PTFE with PTFE content of 4.0 wt %) at 230°C. The experimental results indicated that the presence of PTFE improved the cell morphology of PP foams and broadened the foaming window of PP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

助剂挤出法制备高强度聚四氟乙烯单丝

将聚四氟乙烯(PTFE)与润滑助剂航空煤油混合后均匀挤出,挤出样条脱除助剂,在低于PTFE熔点的温度下高倍拉伸,后经高温紧张热定型,制备高取向PTFE单纤维;通过拉曼光谱、X射线衍射、差示扫描量热分析等方法研究挤出PTFE拉伸过程中材料微细结构的变化,并对PTFE纤维的性能进行表征.结果表明:PTFE在挤出过程中并不会...     

国产聚四氟乙烯纤维的特性与应用

介绍了聚四氟乙烯(PTFE)的化学、物理等特性及其应用。PTFE为大分子线型结构,熔点327℃,分解温度在415℃以上。PTFE纤维具有优良的耐腐蚀性,低摩擦因数,不燃,能耐强酸、强碱、强氧化剂等强腐蚀性试剂或溶剂,耐高、低温性能优良。用PTFE纤维制成的滤材广泛应用于垃圾焚烧、高硫煤除尘等领域。