聚丙烯腈基碳纤维原丝在干湿法纺丝中非溶剂扩散过程的研究

聚丙烯腈基碳纤维具有高强度、高模量、耐高温、耐腐蚀的优良性能,广泛应用于化工、机械、造船等方面。在聚丙烯腈基碳纤维的干湿法纺丝中,纺丝原液进入凝固浴后发生的非溶剂扩散过程对聚丙烯腈基碳纤维原丝的结构和性能有重要影响。该文通过Fick定律建立了适用于纺丝原液是溶剂、高聚物和非溶剂三组分体系的非溶剂扩散数学模型,指出该模型的适用范围。此外,该文还作出了非溶剂分子的浓度随时间的变化曲线。     

一种聚丙烯腈基中空碳纤维原丝及其制备方法

本发明涉及一种聚丙烯腈基中空碳纤维原丝及其制备方法。本发明的聚丙烯腈基中空碳纤维原丝可用于聚丙烯腈基中空碳纤维的制备。采用含衣康酸的丙烯腈二元共聚体系,或含衣康酸与丙烯酸甲酯的丙烯腈三元共聚体系湿法纺丝工艺配合圆弧狭缝喷丝板纺丝,可以得到多丝束中空碳纤维原丝、该原丝的外径尺寸与结构符合常规预氧化碳化工艺对原丝纤维的要求、纤维表面存在沟槽结构有利于复合材料界面性能的提高。     

纺丝成形工艺和条件对PAN原丝中孔隙的影响

孔隙是聚丙烯腈基碳纤维原丝的一种十分重要的形貌结构,与最终得到的碳纤维的性能密切相关。文章分析和讨论了纺丝成形中原丝孔隙的成因和演变以及对碳纤维性能的影响,并简介了几种表征原丝孔隙的方法。     

专利文摘

<正>碳纳米管改性的聚丙烯腈基碳纤维原丝及其制备方法本发明涉及一种碳纳米管改性的聚丙烯腈基碳纤维原丝及其制备方法,组分包括:碳纳米管和聚丙烯腈,其质量分数比为1%～20%:80%～99%;制备包括,⑴?将聚丙烯腈溶解在溶剂中,配成质量分数为3%～45%的聚丙烯腈溶液,过滤,脱泡;⑵?将聚丙烯腈的溶剂与水配成纺丝凝     

干喷湿纺法制备T700级聚丙烯腈基碳纤维

采用丙烯腈、氨化试剂A、丙烯酸甲酯为聚合单体,以偶氮二异丁腈为引发剂,在溶剂二甲基亚砜中合成了聚丙烯腈原丝纺丝液,经干喷湿纺法纺丝制得聚丙烯腈原丝,经预氧化和炭化得到了T700级高性能聚丙烯腈基碳纤维。采用扫描电子显微镜,差示扫描量热仪,电子万能材料试验机对纤维的性能进行了研究。研究了空气层距离、喷丝头长径比、凝固浴浓度、空气拉伸比对干喷湿纺法制备纤维性能的影响。在空气层距离为40mm、凝固浴浓度为70%、喷丝头长径比为10.0、空气拉伸比为1.8条件下,采用干喷湿纺法制得的T700级聚丙烯腈基原丝及碳纤维的表面光滑、无沟槽,截面形貌为圆形;原丝的拉伸强度可达8.7cN/dtex,拉伸弹性模量可达154.7cN/dtex,碳纤维的拉伸强度可达5 750MPa,拉伸弹性模量可达220GPa。     

熔融纺丝工艺制备碳纤维原丝

聚丙烯腈基碳纤维的制备主要采用溶液纺丝方法,生产过程需要溶剂回收,工艺流程长,因此制造成本高。笔者主要介绍了聚丙烯腈基碳纤维的制备工艺概况,特别介绍了熔融纺丝路线制备聚丙烯腈原丝的方法。利用共聚改性、增塑改性、纺丝后处理等方法,可以制备聚丙烯腈基碳纤维,并提出了由熔融纺丝制备聚丙烯腈基碳纤维的可行路线。     

聚丙烯腈基碳纤维的研究进展

综述了聚丙烯腈(PAN)基碳纤维制备技术现状和进展.分析了对PAN原丝质最有重要影响的PAN化学组成、纺丝溶剂和纺丝技术特点.重点讨论了PAN原丝氧化稳定工艺和机理、碳化过程所发生的化学反应和工艺过程以及石墨化对碳纤维性能的影响.在分析国外碳纤维研究进展的基础上,建议应重点完善PAN原丝生产工艺,利用国内外最新研究成果,采用有效的试验方法,将碳纤维的抗拉强度和杨氏模量作为目标函数,建立各种工艺条件对目标函数影响的数学模型,判别对碳纤维性能有重要影响的参数,并寻找出高性能碳纤维生产较为理想的工艺条件.     

二甲基亚砜一步法碳纤维用聚丙烯腈原丝生产工艺

叙述了二甲基亚砜一步法（高转化）高强碳纤维用聚丙烯腈原丝生产的工艺流程。着重讨论了聚合、纺丝的工艺控制。以及工艺控制对聚丙烯腈原丝和最终碳纤维性能的影响。按此工艺生产的聚丙烯腈原丝的质量完全符合高强碳纤维生产的需要。     

喷丝头长径比对PANCF原丝性能的影响

采用不同长径比(L/D)的陶瓷喷丝头进行湿法、干湿法纺丝制备聚丙烯腈基碳纤维(PANCF);研究了L/D对聚丙烯腈/二甲基亚砜(PAN/DMSO)纺丝原液的可纺性及原丝性能的影响。结果表明:随着喷丝头L/D的增大,PAN/DMSO纺丝原液的可纺性提高,PANCF原丝的膨润度逐渐减少,PANCF原丝的结晶度、取向度及强度随之增大,有利于提高纤维的性能。     

干湿纺PAN纺丝溶液的制备及其性能研究

对以硫氰酸钠(NaSCN)水溶液为溶剂,分子量在8－11×10~4适合干湿法纺丝的聚丙烯腈(PAN)纺丝溶液的制备工艺及纺丝溶液的流变性能进行了深入的研究,为纺制高性能PAN基碳纤维原丝提供了实验依据。     

聚丙烯腈初生纤维凝固过程中“皮·芯”结构的研究

通过建立PAN湿法纺丝丝条凝固过程中“皮·芯”结构模型,对PAN湿法纺丝凝固过程进行模拟。结果表明,喷丝头附近的凝固浴浓度降低时,有利于提高纺丝速度和喷丝头拉伸比。     

干喷湿纺法PAN基碳纤维表面处理的研究

以碳酸氢铵为电解质,对干喷湿纺法PAN基碳纤维进行了连续表面处理。通过扫描电子显微镜（SEM）分析其微观结构,同时利用万能材料实验机研究碳纤维及其复合机理。结果表明,随着处理电流密度的增大,碳纤维抗拉强度呈降低趋势。电化学处理碳纤维,电流密度最佳范围应为43．6A·m-^2～54．4A·m^-2,且碳纤维表面官能团对提高复合材料的层间剪切强度起关键作用。     

国内外PAN基碳纤维的研究进展

介绍了聚丙烯腈基碳纤维材料的应用与聚丙烯腈基碳纤维生产技术在国内外的现状与发展,重点介绍了PAN基碳纤维原丝的制备工艺,聚合体系的组成与研制,纺丝工艺的特点及PAN原丝预氧化工艺和PAN的碳化工艺的研究。在现阶段我国聚丙烯腈基碳纤维在生产与研制上与国外的差距,并对高性能碳纤维复合材料产业在我国的发展作了展望。     

Wet-spinning and carbonization of graphene/PAN-based fibers: Toward improving the properties of carbon fibers

Graphene/polyacrylonitrile (PAN)-based composite fibers, as monofilaments, multifilaments, and yarns, were prepared through a facile solution mixing and wet-spinning method. The PAN-based (PANb) precursor was synthesized via reversible addition–fragmentation chain transfer polymerization with N-isopropylacrylamide as a comonomer. Following wet-spinning, the PANb yarns were carbonized at 900 °C. Scanning electron microscopy images confirmed the presence of a homogenous dispersion of graphene nanosheets inside the polymer matrix. It has been shown that the addition of graphene not only enhanced the thermal and mechanical properties of the PANb fibers, but also improved their graphitic structure after heat treatment. Tensile strength and Young's modulus of the PANb yarns were increased by 28 and 20%, respectively, on addition of 0.5 wt % graphene. Raman spectra demonstrated improvement in the graphitic structure of the carbonized yarns even at low graphene content. These graphene/ PANb fibers show potential as a suitable precursor for the development of next generation carbon fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47932.     

Study on the Coagulation Mechanism of Wet-Spinning PAN Fibers

The mechanism of coagulation process of polyarylonitrile (PAN) wet-spinning was studied based on the numerical analysis of the coagulation of viscous polymer solution by diffusional interchange with a bath. Experiments were performed in order to determine the diffusion coefficient of solvent and non-solvent. The numerical solutions of Fick’s second law equations for diffusion were obtained by using the MOL method. The microstructure of nascent fibers is investigated by Transmission Electron Microscope (TEM) and Electron Probe Microanalyser (EPMA). It is found that the speed of outflow solvent is more rapid than that of influent non-solvent. The speed of concentration change of solvent and non-solvent is rapid in outside layers of filament (0.2R) and slow in inner layers. The solvent concentration is keeping a high value at the center of filament. TEM and EPMA show that the microstructure is a typical layered structure. The thickness of dense skin is about 0.2R. The core region of fiber is very loose.     

铜和硼化物对PAN基炭纤维的催化石墨化作用

将单质铜、硼酸、PAN基炭纤维进行混合研磨,经过石墨化炉高温处理,利用X射线衍射检测了铜和硼在热处理过程中的变化,研究催化剂的量和热处理温度对石墨化度的影响,结果显示炭纤维的石墨化度由25.6%提高到95.6%,表明铜和硼化物二元催化剂体系要比一元催化剂体系铜或硼更能显著地提高PAN基炭纤维的石墨化度,并完善炭纤维的石墨晶型。     

Synthesis of emulsion-templated porous polyacrylonitrile and its pyrolysis to porous carbon monoliths

PolyHIPEs are emulsion-templated polymers synthesized within high internal phase emulsions (HIPEs). The miscibility of acrylonitrile (AN) with water has made it difficult to synthesize PAN-based polyHIPEs. This paper describes the successful synthesis of PAN-based polyHIPEs by crosslinking through copolymerization with divinylbenzene (DVB), by stabilization with a polyglycerol polyricinoleate surfactant, and by initiation with both oil- and water-soluble initiators. The PAN-based polyHIPEs had porosities of over 86% and porous structures that were different from those of typical polyHIPEs. This paper also describes the production of porous carbon monoliths through the pyrolysis of these PAN-based polyHIPEs. Pyrolysis did not produce significant changes in the porous structures, which were quite similar to those of the original polyHIPEs. The porosities were around 95% and the carbon monoliths were largely macroporous and mesoporous, with some microporosity. These results indicate that PAN-based polyHIPE templates can be used for the a priori design of porous carbon monoliths.     

凝固浴浓度在线控制在PAN原丝生产中的应用

介绍了一种用于PAN原丝工业化生产装置的智能控制系统及其工作原理。通过在线监测凝固浴浓度（DMSO溶液），自动调节补水量，以维持凝固浴浓度的稳定。该装置的使用可提高工艺参数的控制精度，在腈纶湿法纺丝及PAN基碳纤维原丝工业化生产中具有广阔的应用前景。     

高温处理对PAN基炭纤维热稳定性的影响

将2种PAN基炭纤维经3次2 500℃高温处理,研究了不同次数处理后炭纤维的晶格参数、灰分含量以及炭纤维在静态和流动空气中的热稳定性。结果表明高温处理能改善PAN基炭纤维的石墨微晶结构,减少灰分含量;随着高温处理次数的增加,炭纤维在静态空气和流动空气中的氧化失重率降低,热稳定性提高。