熔纺与干纺氨纶结构与性能的研究

研究了熔纺与干纺氨纶的物理机械性能,两种纤维的性能基本相似,但干纺氨纶的回弹性和耐热性明显优于熔纺氨纶,从两种纤维结构分析,得出纤维的优异性能与微相分离结构密切相关。     

熔纺氨纶的工业现状及发展前景

介绍了熔纺氨纶在研究开发和产业化方面的最新发展概况,对干纺氨纶和熔纺氨纶的产品性能和经济技术指标进行了综合对比,并对熔纺氨纶的应用方向、市场需求进行了分析,对熔纺氨纶的发展前景作了展望。     

国产熔纺氨纶切片蓄势待发

概述了我国熔纺氨纶生产现状,指出国产氨纶切片已投放市场,结束了熔纺氨纶依赖巴斯夫、诺誉切片的历史,给熔纺氨纶增加了很大的底气。国产氨纶切片在等待时机,等待熔纺氨纶的复苏。     

第四十讲 发展熔纺氨纶正当时

概述了我国熔纺氨纶生产现状,指出国产氨纶切片已投放市场,结束了熔纺氨纶依赖巴斯夫、诺誉切片的历史,给熔纺氨纶增加了很大的底气。国产氨纶切片在等待时机,等待熔纺氨纶的复苏。     

中国氨纶的现状与未来

简单比较了熔纺及干纺氨纶的优缺点,对国外氨纶的市场情况及国内氨纶的现状及发展情况进行了详细的介绍,并对运作中国氨纶市场提出了建议。     

熔纺氨纶结构和性能的研究

采用红外光谱和热分析方法研究熔纺氨纶的结构特点,分析分子结构对性能的影响。干纺氨纶存在较强脲基伸缩振动峰,表明分子结构中存在脲基;熔纺氨纶的N—H、C—H吸收峰相比TPU切片位置向高波数方向移动,且吸收较强,表明熔纺氨纶中氢键作用减弱,微相分离程度变大;熔纺氨纶的各项耐温性能及热分解温度相比TPU切片都有提高,说明通过熔融交联反应,改善了熔纺氨纶的热稳定性。     

氨纶发展概况与熔纺氨纶新进展

本文介绍了世界聚氨酯纤维 (氨纶 )的最新发展概况、干纺氨纶和熔纺氨纶的综合技术经济和产品性能对比、熔纺氨纶在研究开发和产业化方面的新进展 ,并重点介绍了Zinser公司的氨纶纺丝设备 ,最后对未来熔纺氨纶的发展作了简要的展望。     

熔纺氨纶

通过国内外氨纶工业现状、熔纺氨纶的发展和优越性综合分析,重点介绍了伊文达-菲瑟公司熔纺氨纶工艺、设备和产品特点,揭示了熔纺氨纶的发展前途和投资热潮。     

影响熔融氨纶生产的几个重要因素

1熔融氨纶制造工艺技术 纤维级聚氨酯切片（采用一步法合成的纤维级热塑性聚氨酯粒子）,经干燥、熔融、计量、纺丝、卷绕、上油、平衡等工序,即得到熔融纺丝氨纶产品。最初熔融纺丝氨纶产品在弹性回复率、耐热性等方面还不如干纺氨纶,但随着纤维级聚氨酯切片技术生产日益成熟及熔融纺丝技术的完善．熔融纺丝氨纶产品已可和干纺氨纶产品相媲美。     

熔纺氨纶配套助剂急需国产化

我国熔纺氨纶生产技术日渐成熟，目前已有十多家企业成功研制开发了熔纺氨纶纺丝技术。这些国产技术投资少，有些性能已超过国外水平，但与这些成熟的国产熔纺氨纶生产技术相比，与之配套的助剂国产化更迫在眉睫。     

添加剂对熔纺氨纶结构与性能的影响

基于添加剂与聚氨酯之间的化学与物理作用,选择了合适的聚合物和无机纳米颗粒等添加剂,研究了这些添加剂对熔纺氨纶制备及其对氨纶丝的微观结构和力学等物理性能的影响。研究结果表明:增塑剂S改善了氨纶的结晶特性,进而改善力学性能与热稳定性;添加剂的并用在一定程度上可改善氨纶丝弹性与耐疲劳性。     

支化与交联型聚氨酯弹性体的合成与性能分析

为提高聚氨酯弹性体力学性能和耐热性,本文以聚己二酸二乙二醇酯二醇、二苯基甲烷二异氰酸酯和 1,4-丁二醇为原料,以聚氧化丙烯三醇（PPG-3）或丙三醇为支化单体,并通过调控其添加量（1%、3%和5%,相对于PDGA-2000的摩尔分数）,采用本体预聚物法合成支化或交联型聚氨酯弹性体。与线型聚氨酯相比,支化聚氨酯具有较高机械强度和耐热性。添加3% PPG-3所制备支化聚氨酯的拉伸强度提高170%（33.9MPa）,撕裂强度提高36%（90.7MPa）,维卡软化点温度为95.1℃;然而,5%的丙三醇引发交联结构的形成,交联型聚氨酯的拉伸强度提高154%（31.8MPa）,撕裂强度提高26%（84.4MPa）,维卡软化点温度为150.6℃。此外,PPG-3和丙三醇发挥聚氨酯软段和硬段相容剂的作用,抑制微相分离,使聚氨酯弹性体的橡胶平台增大。动态流变行为测试结果表明,支化和交联型聚氨酯弹性体具有更高的弹性模量和复数黏度。     

Study of telechelic polyurethane with perfluoropolyether tails

Well architectured polyurethanes containing fluorine are expected to be applied in medical devices as well as other fields. A telechelic polyurethane end-capped with perfluoropolyether segments was prepared from polyether glycol as a soft segment, 4, 4′-methylene-bis-(phenylisocyanate), and monofunctional perfluorinated oligomer. The telechelic polyurethane was studied by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), contact angle and atomic force microscopy (AFM). XPS results indicated that the surface of the fluorine containing polyurethane was enriched with fluorine component. It exhibited a hydrophobic property with a water contact angle of 113°. The polyurethane terminated with perfluoropolyether segments showed a better thermal stability. A mechanism was proposed to explain thermal decomposition of polyurethanes. DSC results suggested that the tail-like perfluoropolyether segments would disrupt main chain packing, then raise crystallization potential barrier, and the perfluoropolyether segments did not affect the bulk microphase-separated structure.     

Thermal stability of polyurethanes based on vegetable oils

A series of polyurethanes from polyols derived from soybean, corn, safflower, sunflower, peanut, olive, canola, and castor oil were prepared, and their thermal stability in air and nitrogen assessed by thermogravimetric analysis, FTIR, and GC/MS. Oil‐based polyurethanes generally had better initial thermal stability (below 10% weight loss) in air than the polypropylene oxide‐based polyurethane, while the latter was more stable in nitrogen at the initial stage of degradation. If weight loss at a higher conversion is taken as the criterion of stability, then oil polyurethanes have better thermal stability both in air and in nitrogen. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1723–1734, 2000     

Effect of isocyanates on the crystallinity and thermal stability of polyurethanes

Polyurethanes were synthesized from polyester and butanediol with three different diisocyanates, i.e., 4,4´-diphenylmethane diisocyanate (MDI), m-xylene diisocyanate (XDI), and 2,4-toluene diiscynate (TDI). The effect of chemical structures of diisocyate compounds on the degree of crystallinity and the thermal stability were observed. Differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) were used to determine the degree of crystallinity of the hard segment. The thermal degradation of polyurethanes was studied by the thermogravimetric method. It has been shown that the polyurethane hard-segment crystallinity decreases in the following order: MDI> XDI> TDI>. The experimental results also indicated that polyurethanes with aralkyl diisocyanates, i.e., XDI, had the best thermal stability. The polyurethanes synthesized from aromatic diisocyanates, i.e., MDI and TDI, had worse thermal stability than from XDI. However, owing to the higher degree of hard-segment crystallinity for polyurethanes from MDI, these polyurethanes had a better thermal stability than those based on TDI. © 1996 John Wiley & Sons, Inc.     

Melt mixing of carbon fibers and carbon nanotubes incorporated polyurethanes

Polyurethane composites filled with carbon fibers (CF) and carbon nanotubes (CNT) were prepared by mixing and injection molding, and its mechanical as well as their thermal properties were investigated. Dynamic mechanical analysis (DMA), thermogravimetry analysis (TGA), and thermal conductivity tests were done, and the properties were evaluated as a function of the filler concentration. The storage modulus of the composites increased with fillers concentration, which also mean the increase of the stiffness, suggest a good adhesion between the polyurethane matrix and the fillers. Addition of more CF and CNT to the composites broadened and lowered the peak of tan δ specifies that the polyurethane composite became more elastic because there is a good adhesion between the fillers and the matrix. The addition of carbon fillers improves the thermal stability of the polyurethane. The inclusions of CNT show a better thermal stability when compared with CF. The addition of carbon fillers also increased the thermal conductivity of the polyurethane composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of silicon and phosphorus on the degradation of polyurethanes

A series of polyurethanes containing silicon and phosphorus was prepared from 4,4′‐diphenylmethane diisocyanate (MDI), poly(tetramethylene ether glycol) (PTMG), diphenylsilanediol (DSiD), and methylphosponic acid (MPA). ¹H‐NMR spectra determined the qualitative and quantitative characteristics of these polymers. The thermal stability and activation energy for thermal degradation of these polymers were measured by thermogravimtry and compared with pure polyurethane (PU). The DSiD incorporated into the main chain of the polymer improved the thermal stability of PU, while the phosphorus‐containing polyurethane (P–PU) displayed a lower thermal stability than that of pure PU. The activation energies at various degradation stages for the pure PU, silicon‐containing polyurethane (Si–PU), and P–PU polymers were calculated by the Ozawa method. The activation energies of the Si–PU polymers were higher than were those of pure PU and increased according to the increase in the DSiD content. However, the P–PU polymers' activation energies were smaller than were those of pure PU, and they decreased with increasing phosphorus content in the range of 0.1 ≤ conversion ≤ 0.5, whereas the reverse was true between 0.6 and 0.9. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 881–899, 2001     

聚硅氧烷改性水性聚氨酯的合成及其表面性能

以聚氧化丙烯二醇(PPG)、双羟基亲水性聚硅氧烷多元醇(UC3667)为软段,异佛尔酮二异氰酸酯(IPDI)、1,4-丁二醇(BDO)、二羟甲基丙酸(DMPA)、乙二胺(EDA)为硬段,制备了一系列聚硅氧烷改性水性聚氨酯(WPUs)。用DLS和FTIR表征了水性聚氨酯乳液粒径和膜结构。通过热重分析、拉伸测试、接触角测试、XPS对水性聚氨酯胶膜的性能进了测定。结果表明:随着聚硅氧烷加入量的增多,水性聚氨酯膜拉伸强度先增大后减小;且聚硅氧烷的加入提高了水性聚氨酯膜的热稳定性、断裂伸长率、接触角,降低了水性聚氨酯膜的表面能。当聚硅氧烷质量分数为5.0%时,胶膜表面的硅迁移量达到饱和,表面能为27.27 mJ/m~2。     

Preparation of reactive amphoteric polyurethane with multialdehyde groups and its use as a retanning agent for chrome-free tanned leather

Leather retanning agents are of great meaning for the reactive competence and thermal, physical, and mechanical properties of treated leather fibers. For this motif, reactive amphoteric polyurethane with multialdehyde groups (AAPU) was prepared by a polyaddition reaction with isophorone diisocyanate, poly(tetrahydrofuran glycol), 2,4-dihydroxybenzaldehyde, 2,2-dihydroxymethyl propionic acid, and N-methyl diethanolamine as raw materials and was then used as a retanning agent to explore its effects on leather fibers. The structure of AAPU was confirmed by UV, Fourier transform infrared, and ¹H-NMR spectroscopy. An average particle size of 42.6 nm and an isoelectric point of 5.16 were determined. The thermal stability, physical and mechanical properties, and morphology of the AAPU-treated leather fibers and their reactivities to anionic materials were investigated. Because of the crosslinking effect of multisite covalent bonds, which resulted from reactions between the aldehyde groups in AAPU and the pendant amido groups from collagen fibers, and the role of the cationic groups in AAPU, the thermal stability of the treated leather fibers and their reactivity to anionic materials, such as dyestuffs and fatliquoring agents, were enhanced. Thus, the absorption rate of dyes was almost as high as 99.89%, and the physical and mechanical properties of the AAPU-treated final leather fibers were superior to those of the contrast. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47940.