聚苯撑吡啶并咪唑纤维研究(一)

聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑){Poly[2,6-diimidazo(4,5-b：4′,5′-e)pyridinylene-1,4(2,5-dihydroxy)phenylen],PIPD}纤维(简称M5)是荷兰Akzo Nobel Central Research经过10多a努力研制成功的一种新型刚性聚苯撑吡啶并咪唑(Polypyridobisimidazole)系聚合物纤维,其力学性能突出,耐热性及耐燃性好,由于大分子之间具有独特的氢键网状结构,纤维的抗压缩性能优于其它有机高性能纤维,目前该纤维由荷兰Magellan Systems International,LLC开发生产．本文对PIPD纤维的制备、纤维结构与性能以及应用等进行介绍和讨论．     

聚苯撑吡啶并咪唑纤维研究(二)

聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑){Poly[2,6-diimidazo(4,5-b：4’,5’-e)pyridinylene-1,4(2,5-dihydroxy)phenylen],PIPD}纤维(简称M5)是荷兰Akzo Nobel Central Research经过10多a努力研制成功的一种新型刚性聚苯撑吡啶并咪唑(Polypyridobisimidazole)系聚合物纤维,其力学性能突出,耐热性及耐燃性好,由于大分子之间具有独特的氢键网状结构,纤维的抗压缩性能优于其它有机高性能纤维,目前该纤维由荷兰Magellan Systems International,LLC开发生产．本文对PIPD纤维的制备、纤维结构与性能以及应用等进行介绍和讨论．     

聚酰胺纤维

20123040聚酰胺6-共聚酰胺-叠层硅酸盐纤维Kristofic Michal…;Fibres&Textiles in Eastern Europe,2007,15(5～6),p.34(英)为了改善PA6纤维的吸附和电性能,研究使用大分子改性的PA6纤维。改性剂由二元高分子半结晶共聚物(e-己内酰胺作主要组分,质量分数分别为5%、17%、30%来自己二酸十二乙撑三胺的尼龙盐)、PA6均聚物在纳米添加剂蒙脱土存在下合成而构成,同时,评估了这些改性剂的基本特征。质量分数分别为10%、20%、30%和50%合成的改性剂用于制备混合的M/F聚e-己内酰胺-改性剂纤维,     

有机特种纤维介绍(二)

对有机特种纤维中的超高相对分子质量聚乙烯(UMHWPE)纤维、聚对苯撑苯并二噁唑(PBO)纤维、聚酰亚胺(P)I纤维、聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑)(PIPD)纤维的结构与性能、发展情况、制备方法以及主要应用领域进行了简要介绍,最后简要展望了这4种特种纤维的发展前景。     

纤维类型对C_f/SiC复合材料力学性能的影响

本工作以AlN和Y2 O3为烧结助剂 ,采用先驱体转化 -热压烧结的方法制备出了Cf/SiC复合材料 .研究了纤维类型影响复合材料力学性能的本质原因 .由于T3 0 0纤维的制备温度明显低于M 40JB纤维的制备温度 ,因此 ,与M 40JB纤维相比 ,T3 0 0纤维的石墨化程度较低且含有较多的杂质 ,从而导致T3 0 0纤维表面的活性强 ,而M 40JB纤维表面的活性较弱 .正是这种结构和成分的差别 ,使T3 0 0纤维与基体的结合较强 ,而M40JB纤维与基体的结合较弱 ,因此以T3 0 0纤维为增强相的复合材料呈现脆性断裂 ,而以M 40JB纤维为增强相的复合材料则呈现韧性断裂 ,该复合材料具有较好的力学性能     

含嘧啶杂环聚酰亚胺纤维的湿法纺丝成形及结构性能

以2,5-二(4-氨基苯基)嘧啶与3,3',4,4'-联苯二酐聚合得到高分子质量的聚酰胺酸溶液,采用"两步法"湿法纺丝制备聚酰亚胺纤维,研究了凝固浴组成对纤维成形形貌的影响以及热亚胺化、热牵伸作用对纤维聚集态结构的影响。三元相图与扫描电镜结果显示:过快或过慢的凝固速度均不利于形成规则、致密结构的纤维,以体积比5/5的H2O/DMAc混合溶液为凝固浴时,纤维成形较佳。同步辐射结果显示:热环化、热牵伸均可促进纤维形成更为完善的晶态、取向结构。最终得到聚酰亚胺纤维的最高拉伸强度、模量分别达1.72 GPa与95.1 GPa,此外所得纤维具有优异的耐热稳定性。     

静电纺丝抗菌聚氨酯纳米纤维的结构与性能

在聚氨酯/四氢呋喃-N,-二甲基甲酰胺(PU/THF-DMF)溶液中分别添加质量分数为5%的TiO_2-Ag,HM-98,三氯均二苯胺(TCC),4-氯-3,5-二甲基苯酚(PCMX),2,4,4'-三氯-2'-羟基二苯酚(DP 300),ε-聚赖氨酸(ε-PLYS)抗菌剂通过静电纺丝技术制备了PU抗菌纳米纤维,并对其性能和结构进行了研究。结果表明:含ε-PLYS,HM-98,TiO_2-Ag,DP300抗菌剂的抗菌PU纳米纤维对金黄色葡萄球菌和大肠杆菌的抗菌效果较为优良,抗菌率均达到了99.9%以上,TCC、PCMX抗菌剂的抗菌效果较差;添加HM-98抗菌剂降低了纺丝溶液的可纺性,但纤维直径有所下降;抗菌剂在PU中的分散性好。     

膨胀型阻燃剂在纤维及纺织品上的应用

介绍了螺环季戊四醇二磷酰氯(SPDPC)、环状1,3-丙二醇磷酰氯(CPPC)、环状2,2-二乙基-1,3-丙二醇磷酰氯(CDPPC)3种多元醇磷酰氯膨胀型阻燃剂(IFR)及其在纤维和纺织品上的应用；分析了3种纤维磷酸化的条件及结果。IFR能与聚酰胺纤维、羊毛及棉纤维反应而使之磷酸化,赋予纤维以耐久阻燃性。这类阻燃纤维耐沸水处理,具有膨胀型特征,与环境兼容,建议尽早开发,实现工业化生产。     

纤维球过滤联碱母液的试验

采用纤维球过滤器精制MⅡ ,试验表明 ,纤维球过滤器具有过滤速度大 ,截污容量高 ,再生容易 ,设备结构与操作相对简单等优点 ,可望在生产中应用。     

纤维类型对Cf/SiC复合材料力学性能的影响

本工作以AIN和Y2O3为烧结助剂,采用先驱体转化－热压烧结的方法制备出了Cf/SiC复合材料,研究了纤维类型影响复合材料力学性能的本质原因,由于T300纤维的制备温度明显低于M40JB纤维的制备温度,因此,与M40JB纤维相比,T300纤维的石墨化程度较低且含有较多的杂质,从而导致T300纤维表面的活性强,而M40JB纤维表面的活性较弱,正是这种结构和成分的差别,使T300纤维与基体的结合较强,而M40JB纤维与基体的结合较弱,因此以T300纤维为增强的复合材料呈现脆性断裂,而以M40JB纤维为增强相的复合材料则呈现韧性断裂,谈复合材料具有较好的力学性能。     

Interfacial behavior of high performance organic fibers

The surface and interfacial properties of different high performance fibers of current interest have been analyzed. The pyridobisimidazole fiber M5 shows a markedly higher polar contribution to its surface free energy than the rest of the organic fibers under study. Interfacial shear strength (IFSS) values measured by means of the microdroplet test indicate that M5 fiber has an IFSS that doubles that of the Kevlar fibers, in agreement with the observed results from surface free energy tests. Armos fiber, a para-aramid material that incorporates imidazole functional groups, shows an average IFSS 30-35% higher than the Kevlar fibers. SEM micrographs of failed microdroplet specimens show different failure mechanisms for the Kevlar KM2, Armos and M5 fibers. The KM2 specimens fail due to complete detachment of surface fibrils from the bulk of the fiber, while Armos specimens fail by the combined effect of microfibrillation on the fiber surface coupled with adhesive failure. In contrast, M5 microdroplet specimens exhibit failure surfaces consisting of partial matrix yielding during droplet debonding, indicative of the high level of interfacial bonding to the surface and higher levels of hydrogen bonding within the fiber that suppress microfibrillation. The higher polar character of the M5 surface can lead to the presence of an interphase region with different mechanical properties from the bulk matrix.     

Effect of hydrogen bonding and moisture cycling on the compressive performance of poly-pyridobisimidazole (M5) fiber

A clear correlation between the degree of intermolecular hydrogen bonding (H-bonding) and axial compressive strength of pyridobisimidazole (M5) as-spun fiber specimens subjected to varying annealing conditions has been established by means of Fourier transform infrared microspectroscopy and single fiber elastica loop testing. As the water initially contained in the as-spun fiber is removed by heat treatment, improvements in polymer chain orientation promote the formation of intermolecular H-bonds, leading to enhanced fiber compressive strength values. M5 fiber specimens with the highest degree of intermolecular H-bonding of 96 ± 1% are found to have a compressive strength of 1.72 ± 0.09 GPa. Moisture cycling experiments of M5 annealed specimens have provided direct evidence of partial H-bond reversibility in this material, as saturation of M5 annealed fiber resulted in the reduction of the degree of intermolecular H-bonding from 93 to 64%. Upon drying the fiber at 120 °C in an inert atmosphere, the degree of H-bonding returned to the original value of 93%. However, repeated fiber moisture cycling resulted in a monotonic reduction in the degree of H-bonding in both the saturated condition (53%) and dry state (62%). The compressive strength of saturated and dried specimens after moisture cycling was found to be statistically equivalent at a reduced level of 1.29 GPa. The original degree of H-bonding and compressive strength could be recovered by re-annealing the fiber under tension.     

M40J graphite fiber surface molecular self-assembly and the performance of its epoxy composite

Molecular self-assembly (MSA) has been established with nano-silver/triethylenetetramine (TETA) onto M40J graphite fiber surface. MSA facilitates the fiber surface functionalization and enabling the controlled interface structure of the fiber composite. The studies have shown that the MSA on M40J graphite fiber surface in the fiber/epoxy matrix interphase plays a critical role in the mechanical performance of the composite. Detailed surface analysis using surface enhanced Raman spectrum shows TETA being self-assembled by chemical bonds on the fiber surface, and additional insight into the enhancing interphase of the self-assembly M40J fiber/epoxy composite by scanning electron microscopy and nano-compression test. The formation of a nano-silver/TETA/epoxy interphase facilitates a stronger fracture zone relative to the untreated M40J fiber/epoxy weak interface, and increases composite strength by shifting the fracture surface away from the fiber surface. The interlaminar shear strength and the flexure strength of the MSA fiber composite have been increased 20.7% and 24.2% comparing with that of the untreated fiber composite, respectively.     

对位芳纶的生产和应用技术进展(Ⅲ)

简介对位芳纶的供需和研发概况;着重叙述PPTA型芳纶、共聚型芳纶、俄罗斯芳纶等重要对位芳纶产品以及PBO纤维、M5纤维等相关高性能纤维的生产技术和主要性能,探讨了高性能纤维开发生产的通用技术;分析了对位芳纶的应用现状和技术;探讨对位芳纶生产技术和应用技术的发展趋势。     

对位芳纶生产和应用技术进展(Ⅰ)

简介对位芳纶的供需和研发概况,着重叙述PPTA型芳纶、共聚型芳纶、俄罗斯芳纶等重要对位芳纶产品以及PBO纤维、M5纤维等相关高性能纤维的生产技术和主要性能,探讨了开发生产高性能纤维的通用技术;分析了对位芳纶应用的现状和技术;预测对位芳纶生产技术和应用技术的发展趋势。     

对位芳纶生产和应用技术进展(Ⅱ)

简介对位芳纶的供需和研发概况;着重叙述PPTA型芳纶、共聚型芳纶、俄罗斯芳纶等重要对位芳纶产品以及PBO纤维、M5纤维等相关高性能纤维的生产技术和主要性能,探讨了开发生产高性能纤维的通用技术;分析了对位芳纶应用的现状和技术;探讨对位芳纶生产技术和应用技术的发展趋势。     

高强度海藻酸盐纤维的制备

采用湿法纺丝方法制备高强度海藻酸盐纤维,研究了影响纤维断裂强度的因素。结果表明:海藻酸钠的β-D-甘露糖醛酸单元(M)/α-L-古罗糖醛酸单元(G)质量比越高,纤维断裂强度越低。采用M/G值为0.32的海藻酸钠为原料,氯化钙水溶液为凝固液,纺丝液质量分数为5.0%,凝固浴质量分数为4.5%,凝固浴温度为40℃,纤维烘干温度为30℃,可制得断裂强度达4.675 cN/dtex的高强度海藻酸盐纤维。     

A novel dual colorimetric fiber based on two acid-base indicators

A novel dual colorimetric fiber based on two acid-base indicators was synthesized by first aminating commercially available polyacrylonitrile fiber with tetraethylenepentamine and then covalently immobilizing ethyl orange moieties through an alkylation reaction and a diazo coupling reaction; finally, the fiber was grafted with phenolphthalein using a Mannich reaction. The functionalized fiber was characterized by elemental analysis, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier-transfer infrared spectroscopy (FTIR) and UV-vis spectroscopy, and its color-changing properties, response speed, reusability and photostability were all investigated. This fiber exhibits a remarkable color change from deep pink (pH < 1.1) to yellow (1.1 < pH < 13.0) and then to dark violet (pH > 13.0). Moreover, this fiber shows a fast response time (<1 s for 1 M HCl and 1 M NaOH), high photostability (>60 days) and excellent reusability (>300 times).     

竹炭改性涤纶短纤维的结构与性能

探讨了竹炭改性涤纶短纤维,并对竹炭改性涤纶短纤维的远红外发射率及负离子发生量等进行了测试.结果表明:竹炭改性涤纶短纤维中的竹炭粉体具有多孔结构,且在纤维中能均匀分散,竹炭改性涤纶的负离子发生量达5 200个/m3,高于普通涤纶,负离子释放稳定;功能纤维远红外发射率高达0.88,其白度为57.29%,线密度和断裂强度超过...     

Influence of unwoven roving and woven fabric carbon fiber reinforcements on reaction-to-fire properties of polymer matrix composites

The influence of carbon fiber orientation on reaction-to-fire characteristics of layered polymer matrix composites is investigated in detail. M18-1/G939 as woven fabric and M18-1/G947 as unwoven roving prepregs with identical, epoxy based matrix composition were laid-up to give 1 to 8 mm thick unidirectional and quasi-isotropic laminates. Fundamental reaction-to-fire properties of these composites are interpreted on basis of the matrix components: epoxy resin and polyetherimide, as well as contained flame retardants magnesium hydroxide and zinc borate. Cone calorimetry and temperature distributions through the laminate show, that the velocity of combustion is influenced by fiber orientation for a given resin. For an unwoven roving it is confirmed that a quasi-isotropic fiber orientation leads to faster ignition, due to preferred delaminations, but retards burning processes more effectively than a unidirectional lay-up. This fundamental principle is extended to woven fabric reinforcements, however with less pronounced effects. Migration velocities of the pyrolysis zone are measured and additionally, decomposition of carbon fibers is considered. A comparison with a similar epoxy based matrix system without toughener and flame retardants: RTM6/G939 is carried out, in order to assess the effects by fiber orientation.