Influence of fluorine-containing side chain on the properties of waterborne polyurethane-urea

In order to prepare waterborne polyurethane with excellent water resistance and thermodynamic properties, a series of side chain fluorinated waterborne polyurethane-urea (FWPU-UA) was synthesized with polytetramethylene ether glycol, N-(2-methyl-1,3-propanediol-2′-)-perfluoro-1-butanesulfonyl amine (NPBA), isophorone diisocyanate, and isophoronediamine. With the increase of NPBA content, the weight loss temperature, glass transition temperature, and tensile strength of FWPU-UA were all improved. Gaussian fitting analysis of infrared data and density functional theory simulation proved that the introduction of fluorine side chains increased the interaction of hydrogen bonding in the FWPU-UA. X-ray photoelectron spectroscopy analysis indicated that the aggregation of fluorine atoms on the surface of film were caused by the migration and enrichment of fluorine side chains. Furthermore, the water resistance of polyurethane-urea film could be significantly improved by adding a small amount of NPBA, and the seven-day water absorption rate of polyurethane-urea film was reduced from 30.13% to 12.55%.     

Stable Light-Emitting Electrochemical Cells Using Hyperbranched Polymer Electrolyte

The choice of an adequate electrolyte is a fundamental aspect in polymer light-emitting electrochemical cells (PLECs) as it provides the in situ electrochemical doping and influences the performance of these devices. In this study, a hyperbranched polymer (Hybrane DEO750 8500) blended with a Li salt is used as a novel electrolyte in state-of-the-art Super Yellow (a polyphenylenevinylene) based LECs. Due to the desirable properties of the hyperbranched polymer and the homogeneous and smooth films that it forms with the emitting polymer, PLEC with excellent electroluminescent properties are obtained using a pulsed current bias scheme. The devices are very stable, with lifetimes in excess of 2000 h with initial luminance values above 450 cd m⁻², a peak efficiency of 12.6 lm W⁻¹, and sub-minute turn-on times. The stability of the devices is also studied by measuring the photoluminescence (PL) of the semiconductor during electroluminescent operation. The findings suggest that it is possible to observe the quenching of the PL in vertically stacked devices due to the advancement of the doped fronts in the film and an immediate PL recovery when the bias is removed.     

A Biologically Muscle-Inspired Polyurethane with Super-Tough,Thermal Reparable and Self-Healing Capabilities for Stretchable Electronics

Polymeric elastomers play an increasingly important role in the development of stretchable electronics. A highly demanded elastic matrix is preferred to own not only excellent mechanical properties, but also additional features like high toughness and fast self-healing. Here, a polyurethane (DA-PU) is synthesized with donor and acceptor groups alternately distributed along the main chain to achieve both intra-chain and inter-chain donor-acceptor self-assembly, which endow the polyurethane with toughness, self-healing, and, more interestingly, thermal repair, like human muscle. In detail, DA-PU exhibits an amazing mechanical performance with elongation at break of 1900% and toughness of 175.9 MJ m⁻³. Moreover, it shows remarkable anti-fatigue and anti-stress relaxation properties as manifested by cyclic tensile and stress relaxation tests, respectively. Even in case of large strain deformation or long-time stretch, it can almost completely restore to original length by thermal repair at 60 °C in 60 s. The self-healing speed of DA-PU is gradually enhanced with the increasing temperature, and can be 1.0–6.15 µm min⁻¹ from 60 to 80 °C. At last, a stretchable and self-healable capacitive sensor is constructed and evaluated to prove that DA-PU matrix can ensure the stability of electronics even after critical deformation and cut off.     

Sustainable progress into batchwise coloration of polyurethane nanofibers by using ultrasonic energy

Abstract

In this decade, aesthetic potentials of electrospun polymeric nanofibers for advanced apparels have been studied. For the first time, we studied the sustainable aspects in the batchwise dyeing process of electrospun polymeric nanofibers in terms of conserving thermal energy and reducing the wastewater pollution. The nanofibrous mats were prepared using polyurethane (PU) polymer followed by dyeing with disperse dyes by conventional (CN) dyeing method as well as ultrasonic (US)-assisted dyeing method. Potential of savings in thermal energy (1000?kcal), dwell time (40?min) and quantity of disperse dyes (1.5% on the mass of nanofibers) were realized during the US-assisted dyeing method in comparison with the CN dyeing method. Further, total dissolved solids (TDS) and chemical oxygen demand (COD) contents of dyeing effluents demonstrated considerable ecological merits of the US dyeing method in terms of 30% reduction in TDS and 46% reduction in COD contents in comparison with the CN dyeing method. Excellent color strength (K/S) (reached 10) of dyed PU nanofibrous mats were achieved by US-assisted dyeing method in comparison with the K/S (reached 6) with CN dyeing method. Attenuated total reflectance-Fourier transform infra-red (FTIR) spectroscopy, UV–Vis spectrophotometer and Scanning electron microscopy (SEM) analysis were also applied during the study for characterization.     

超支化聚合物对羊毛织物的改性研究

为了改善羊毛织物的防毡缩性能,利用三羟甲基磷(THP)交联作用,将端氨基超支化聚合物(HBP-NH2)共价结合到羊毛纤维上,并测试整理后织物防毡缩、抗菌和染色性能及断裂强力变化。结果表明:单独使用超支化聚合物处理,羊毛织物的毡缩率由20.69%下降到17.31%,未达到羊毛织物防毡缩的目的;而经三羟甲基磷/超支化聚合物处理后,羊毛织物的毡缩率下降到7.43%,达到机可洗标准;且抑菌率达92.37%,低温条件下羊毛织物的染色性能也得到明显改善。     

聚氨酯/相变蜡蓄热调温功能整理剂的制备及其在棉织物上的应用

针对传统相变微胶囊后整理法制备蓄热调温纺织品时存在制备工序繁杂、效率低等难点,开发了一种简便快捷的后整理法。选用相变蜡、聚氧乙烯辛基苯酚醚-10(OP-10)乳化剂和水性聚氨酯为主要组分,经高剪切乳化制备蓄热调温功能整理剂,利用浸轧—焙烘方式对棉织物进行整理。优化乳化剂用量、相变蜡与聚氨酯配比及焙烘温度,并测定整理后棉织物及背心的蓄热调温性能。结果表明:当OP-10质量分数为5%,相变蜡与聚氨酯的质量比为1.5∶1,焙烘温度150 ℃时,整理剂在纤维表面原位成膜形成包裹纤维的蓄热调温薄膜,从而赋予棉织物蓄热调温功能;整理后棉织物具备蓄热调温功能,由其所制作的背心具有显著的蓄热调温功能。     

超细纤维合成革的染色与功能整理研究进展

为了解决超细纤维合成革在制备、染色以及功能整理等方面出现的问题,系统阐述了超细纤维合成革的发展历程以及未来超细纤维合成革的发展方向;分析了染色工艺、染色助剂、染色基布的改性对聚酰胺超细纤维合成革染色性能的影响,评述了聚酯超细纤维合成革的染色现状;总结了国内超细纤维合成革经功能整理后的附加性能,包括阻燃、防污、抗静电、抗菌、耐寒、调温等。最后指出了未来超细纤维合成革在制备方式、高性能染色以及功能化整理方面应大力发展的方向,以对企业的产品优化升级、提高产品的市场竞争力提供指导。     

单组份聚氨酯炮孔填塞剂应用性试验

炮孔填塞是爆破施工过程中的一个关键环节,也是践行精细爆破设计理论的重要措施。传统的炮泥填塞存在着诸多不足,为此,研制了以聚氨酯为基材的TK炮孔填塞剂,通过大量基础性能研究和隧道现场工业性试验,论证了其作为炮孔填塞材料可降低炸药单耗,提高单循环进尺和炮孔利用率,减小空气冲击波、爆破噪声等有害效应的影响,且是安全可靠的。TK炮孔填塞剂优良的填塞效果、方便快捷的施工方法及显著的经济效益,方便于在爆破工程中推广应用。     

Porous polyurethane film fabricated via the breath figure approach for sustained drug release

The breath figure (BF) method is an effective process for fabricating porous polymeric films. In this study, we fabricated porous polymer films from thermoplastic polyurethane (PU) through static BF with CHCl₃ as a solvent under 55–80% relative humidity. The porous PU films were prepared within various pore structures and sizes, which were adjustable, depending on the fabrication conditions. The humidity and exposure time were examined as variable parameters affecting the surface morphology, wettability, and cytotoxicity. Atorvastatin calcium, a hyperlipidemic agent, was loaded into the porous films during the casting process, and the drug-loading and drug-releasing behaviors of the porous PU membranes were evaluated. Approximately 60–80% of the drug was released in 14 days. The films exhibited sustained drug-release performances because of the hydrophobicity and nonbiodegradable nature of PU for perivascular drug administration. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47658.     

Hydrolysis-resistant polyurethane elastomers synthesized from hydrophobic bio-based polyfarnesene diol

Hydrolytic stability is an essential requirement for polyurethanes (PUs) that are used in highly humid and aqueous environments. In this study, hydrolysis-resistant PU elastomers (PUEs) are synthesized based on hydrophobic bio-based polyfarnesene diol (PFD), which contains unique “bottle brushes” structure (with long branched hydrocarbon side chains). The effect of hard segment (HS) content, ranging from 30 to 50%, on the morphology and properties of PUEs is investigated by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, tensile, water absorption, and contact angle measurements. The results show that there are prominent phase separations in the synthesized PUEs. The PUEs show a three-stage degradation process and two T_g, one is at about −66 °C and the other 61 °C, which are related to the soft segment and HS, respectively. Water contact angles of PUEs increase from 98.6 to 105.2° with the increasing of PFD structural unit fraction. After being immersed in deionized water for 30 days, PUEs show no significant degradation of both tensile strength and elongation at break, and mass changes of all samples are less than 0.5%. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47673.