聚丙烯腈基超细碳纤维毡的制备及其表征

采用静电纺丝法制备了不同黏均分子质量(Mη)的聚丙烯腈(PAN)超细纤维毡,并通过280℃预氧化和900℃碳化进一步制备超细碳纤维毡。讨论了Mη对纤维制备的影响,发现PAN的Mη大于3×105则不利于静电纺丝,小于5×104则纤维毡发脆,无法进一步加工处理成碳纤维毡。用场发射扫描电镜、红外光谱、X-射线衍射对纤维毡进行表征,结果表明:随着PAN相对分子质量的升高,碳纤维的直径和得率增大。此外,抗拉强度测试表明:随着相对分子质量的增大,超细碳纤维毡的抗拉强度增加。     

超细碳纤维毡的制备及其形貌研究

采用静电纺丝法制备了聚酰胺酸（PAA）无纺布纤维毡,通过亚胺化工艺得到聚酰亚胺（PI）纤维毡,再以PI纤维毡为前驱体经高温碳化工艺制备PI基超细碳纤维毡,并对制得的PI基超细碳纤维毡进行了扫描电镜（SEM）形貌分析和元素分析。经SEM分析得知,随着碳化温度的升高碳纤维毡中纤维的直径逐渐减小,其分布略变窄,主要分布在200-300nm之间,当碳化温度达到1000℃时,PI基超细碳纤维毡中纤维的碳含量为96.16％。     

预氧化温度对聚丙烯腈纳米纤维结构和性能的影响

通过静电纺丝法制得聚丙烯腈纳米纤维毡,再经过不同的预氧化温度得到预氧化程度不同的纳米预氧化毡。分析了在预氧化毡制备过程中预氧化温度对预氧化毡的结构和性能的影响。研究结果表明:随着温度的升高,拉伸性能和含水率逐渐增强,质量损失率在220～250℃之间快速提高。另外,环化度在220～250℃之间增加得特别快,环化反应主要发生在220℃左右,250℃环化反应基本完全;265℃得到预氧化程度较佳的预氧化毡。     

熔融静电纺PP超细纤维的制备及其工艺研究

采用熔融静电纺丝技术制备了超细聚丙烯(PP)纤维,运用高速摄影技术记录了PP熔体在电场力作用下拉伸成丝的整个过程,并借助扫描电子显微镜(SEM)对不同纺丝工艺下制备的PP超细纤维进行表征.探讨了主要工艺参数对纤维微观形貌的影响.结果表明,在一定范围内,缩短纺丝距离、提高纺丝电压及纺丝温度,都有利于减小所纺纤维直径;提高纺丝环境温度不仅有助于减小纤维直径,同时会导致纤维的自粘结现象;用滚筒来代替平板收集纤维,纤维排列规整,且滚筒转速越高,所得纤维越细.     

聚丙烯腈熔融纺丝技术进展

叙述了聚丙烯腈的结构特征，丙烯腈聚合物的增塑，增塑和非增塑聚丙烯腈熔融纺丝工艺和纤维性质。熔纺制得的聚丙烯腈纤维，适用于纺织、地毯以及用作碳纤维原丝。增塑熔融纺丝技术已达到相当高的水平，熔纺纤维的形态与普通聚丙烯腈纤维类似，但存在皮芯结构，芯部有微孔。制得的聚丙烯腈基碳纤维原丝，拉伸强度达５．５～６．６ｃＮ／ｄｔｅｘ，用这种原丝生产的碳纤维的拉伸强度约为３．６×１０３ＭＰａ，模量约为２．３３×１０５ＭＰａ，伸长率约为１．５％，可制得性能优良的航空航天用复合材料。非增塑熔融纺丝，采用特定的丙烯腈聚合物和纺丝条件，不添加任何增塑剂，用普通熔融纺丝机在１０００ｍ／ｍｉｎ或２０００ｍ／ｍｉｎ以上的速度纺丝，经拉伸可得强度２．２～１１ｃＮ／ｄｔｅｘ、伸长率５％～３０％和模量５５～２２２ｃＮ／ｄｔｅｘ的纤维。     

静电纺丝制备锂离子电池负极用多层柔性聚丙烯腈/沥青碳纤维复合材料的方法

正本发明属于石油化工和碳纳米交叉领域,涉及一种静电纺丝制备锂离子电池负极用多层柔性聚丙烯腈/沥青碳纤维复合材料的方法。首先通过静电纺丝制备聚丙烯腈纤维,脱油和聚乙烯吡咯烷酮的混合溶液再经静电纺丝制备混纺纤维并收集在聚丙烯腈纤维上,重复上述步骤即可制得具有多层结构的聚丙烯腈/沥青复合纤维材料,经过预氧化和碳化,制得多层柔性聚丙烯腈/沥青碳纤     

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。     

热处理对PAN基碳纤维结构与性能的影响

以日本进口碳纤维(T300)和国产聚丙烯腈基碳纤维(GCF)为原材料,采用自制石墨化炉,在一定拉伸条件下,对T300及GCF进行1500～2100℃热处理,制备了不同性能的高模量聚丙烯腈基碳纤维(PAN-CFs)。采用广角X射线衍射、拉曼散射光谱、万能材料测试机等探讨了在热处理过程中PAN-CFs性能的演变规律,研究了PAN-CFs的力学性能与微观结构。结果表明:随着热处理温度升高,PAN-CFs的拉伸强度逐渐下降,拉伸模量逐渐上升,纤维的微晶尺寸和微晶取向度逐渐增大,石墨化程度越来越高,PAN-CFs的微观结构从二维乱层石墨结构向有序的三维层状结构发展。     

一种耐高温碳纤维隔热毡

本发明涉及一种耐高温聚丙烯腈基碳纤维隔热毡、制备方法及其用途,所述的耐高温聚丙烯腈基碳纤维隔热毡中X-Y平面与Z向纤维份数比为50：1-250：1,是以短切长度50-150mm的聚丙烯腈基碳纤维基材制备成为厚度为8～12mm,     

干湿法制备异形PAN原丝及其力学性能的研究

对二甲基亚砜(DMSO)干湿法制备三角形截面聚丙烯腈(PAN)基碳纤维原丝的截面形成因素进行了研究,并比较了不同条件下纤维的性能。结果表明:在干湿法纺制三角形截面PAN基碳纤维原丝过程中,凝固浴条件对PAN纤维的截面影响非常明显,同时凝固浴条件和拉伸条件对纤维的力学性能也有非常显著的影响。     

Filtration properties of electrospun ultrafine fiber webs

Electrospun fiber webs were prepared at various spinning conditions. The effect of electrospinning parameters on fiber morphology and filtration performance of electrospun webs was investigated. The processing variables considered were only the applied voltage and rotation speed of a drum type collector. The fiber diameter and mean pore size of the electrospun webs decreased with increasing applied voltage and collector speed. Pressure drop and aerosol collection efficiency of the electrospun fiber webs were increased with decreasing fiber and pore size. Additionally, it was found that the filtration performance of the electrospun web was much greater than that of a commercial high efficiency air filter media made of glass fibers.     

电纺法制备聚丙烯腈基纳米碳纤维

用电纺法制备了聚丙烯腈（PAN）纳米纤维，用场发射扫描电镜（FESEM）对其形态进行了研究，讨论了不同工艺参数对纤维直径和分散形态的影响。结果发现，纤维直径随着浓度的增加而增大，随着电压升高而减小，接收距离和溶剂类型对纤维直径的影响不大。将形态最好的纤维在240℃下进行活化处理，然后将活化处理过的纤维在氮气氛中煅烧，用FESEM观察了煅烧的纤维直径及形态的变化，红外（IR）分析了纤维化学结构的变化，证实了经900℃煅烧后的纤维为碳纳米纤维。     

聚丙烯腈/二氧化钛杂化纳米活性碳纤维制备与结构变化规律

以聚丙烯腈(PAN)溶液中掺入二氧化钛(TiO2)为纺丝液,用静电纺丝法通过滚筒接收得到PAN/TiO2平行排布的纳米纤维,对该纳米纤维进行预氧化和活化以期得到一种兼具吸附-光催化的掺杂TiO2的活性纳米碳纤维。分别采用X射线衍射分析(XRD)、红外光谱分析(IR)、扫描电镜分析(SEM)等手段进行表征。通过磷酸活化,最终制得了一种新型的PAN-ACF/TiO2纳米纤维,其纳米纤维的平均直径400nm,孔洞平均直径为37nm。     

Mechanical and structural characterizations of simultaneously aligned and heat treated PAN nanofibers

A simple and nonconventional electrospinning technique was employed for producing aligned polyacrylonitrile (PAN) nanofibers. A thermal zone was placed between syringe needles and collector in the electrospinning set up to obtain aligned and heat treated nanofibers. Suitable temperatures for heat treat process of PAN nanofibers was determined using differential scanning spectroscopy (DSC) technique. The influence of treatment temperature was investigated on morphology, internal structure and mechanical properties of collected PAN nanofibers. The average fiber diameter measured from SEM images exhibited decreasing trend at higher temperatures. FTIR spectra indicated no considerable difference between chemical structure of untreated and treated PAN nanofibers. Crystallization degree of PAN nanofibers calculated from WAXD patterns showed relatively low change with treatment temperature. Tenacity values of nanofiber bundles increased with increasing temperature while the extension values had an inverse trend. However, the modulus did not show a regular manner, but treated nanofibers had more modulus than untreated ones. The stress and modulus of PAN nanofibers increased to 112.9 MPa and 7.25 GPa at 270°C, respectively. Nanofibers treated at the highest temperature had the largest amount of crystallinity and strength. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Electrospun polyacrylonitrile nanocomposite fibers reinforced with Fe3O4 nanoparticles: Fabrication and property analysis

The manufacturing of pure polyacrylonitrile (PAN) fibers and magnetic PAN/Fe₃O₄ nanocomposite fibers is explored by an electrospinning process. A uniform, bead-free fiber production process is developed by optimizing electrospinning conditions: polymer concentration, applied electric voltage, feedrate, and distance between needle tip to collector. The experiments demonstrate that slight changes in operating parameters may result in significant variations in the fiber morphology. The fiber formation mechanism for both pure PAN and the Fe₃O₄ nanoparticles suspended in PAN solutions is explained from the rheologial behavior of the solution. The nanocomposite fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectrophotometer, and X-ray diffraction (XRD). FT-IR and XRD results indicate that the introduction of Fe₃O₄ nanoparticles into the polymer matrix has a significant effect on the crystallinity of PAN and a strong interaction between PAN and Fe₃O₄ nanoparticles. The magnetic properties of the nanoparticles in the polymer nanocomposite fibers are different from those of the dried as-received nanoparticles.     

Mass Production of Functional Amine–Conjugated PAN Nanofiber Mat via Syringeless Electrospinning and CVD

Polymeric nanofiber webs have attained much attention because they can provide high surface area with various functional groups. To obtain the polymeric nanofiber webs, electrospinning is the most attractive method because this can provide the versatility of material selection. However, it is relatively difficult to obtain the nanofiber webs, which have highly reactive functional groups and high mechanical strength with high production rate. Here, the helically probed rotating cylinder (HPRC) system based on syringeless electrospinning and chemical vapor deposition (CVD) is introduced to prepare the polyacrylonitrile (PAN) nanofiber webs, having high functional groups and high mechanical strength in fast production rate. The HPRC system can provide the PAN nanofiber webs in high production rate, and the CVD process can provide high reactive functional groups on the PAN nanofiber. In addition, the nanofiber webs can be applied to diverse potential application fields, which require a high number of functional moieties.     

Preparation of well‐controlled porous carbon nanofiber materials by varying the compatibility of polymer blends

The relationships between the compatibility in binary polymer blends and the pore sizes of carbon nanofibers (CNFs) prepared from the blends were investigated. Compatibility was determined by the difference between the solubility parameters of each polymer in the polymer blends. Porous CNFs were prepared by an electrospinning and carbonization process using binary polymer blends, consisting of polyacrylonitrile (PAN) as the carbonizing polymer and poly(acrylic acid) (PAA), poly(ethylene glycol), poly(methyl methacrylate) or polystyrene (PS) as the pyrolyzing polymer. The pore size of the CNFs increased with increasing difference in solubility parameter. The CNFs prepared using the PAN/PAA blend, which had the smallest solubility parameter difference, exhibited a pore size of 1.66 nm compared to 18.24 nm for the CNFs prepared using the PAN/PS blend. The prepared CNF webs with controlled meso‐sized pores showed a stable cycle performance in cyclic voltammetry measurements and improved impedance characteristics. This method focusing on the compatibility in polymer blends was simple to apply and effective for controlling the pore sizes and surface area of CNFs for application as electrode materials in energy storage systems. © 2013 Society of Chemical Industry     

喷丝速度对PAN中空纤维成形的影响

研究了于湿法纺丝工艺中喷丝速度对聚丙烯腈(PAN)中空初生纤维成形与性能的影响.结果表明:喷丝速度对PAN纤维截面的规整性、表面形貌、异形度、声速取向和致密性等均会产生影响.在喷丝速度为0.20～0.45m/min时,PAN纤维中空度与声速取向随着喷丝速度的增加而快速增加,随后其增幅逐渐变小或基本不变.纤维内表面在较高的喷丝速度下会产生条纹、粗糙度增大,纤维外表面无明显变化.