尿素对水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯（IPDI）、聚醚220、聚酯二元醇为主要原料,二羟甲基丙酸（DMPA）为亲水性扩链剂,并分别用乙二胺和尿素作扩链剂,合成阴离子型水性聚氨酯乳液。对比2种扩链剂对水性聚氨酯乳液黏度、膜吸水性及玻璃化转变温度（Tg）的影响.结果表明,增加乙二胺的用量,能提高聚氨酯乳液黏度,降低其膜的吸水性,增大聚合物Tg．而增加尿素的用量对聚氨酯乳液黏度和聚合物Tg没有明显影响,但提高了膜吸水性。说明尿素没有起到扩链作用,但可以作为封端剂在聚氨酯分子末端引入胺基。     

内交联水性聚氨酯胶粘剂的研究

讨论了NCO/OH物质的量比对水性聚氨酯(WPU)性能的影响;分别采用蓖麻油、甘油、三羟甲基丙烷合成内交联型水性聚氨酯,讨论了3种不同内交联剂对WPU耐水性、力学性能、涂膜手感的影响。     

Modified shape memory epoxy resin composites by blending activity polyurethane

A series of modified shape‐memory epoxy resin composites were prepared by blending activity polyurethane (APU). Fourier transform infrared spectroscopy (FTIR), tensile tests, scanning electron microscope (SEM), dynamic mechanical analysis (DMA), and fold‐deploy shape memory tests were used to characterize the structure, mechanical, morphology, thermodynamics, and shape memory performance of these materials. FTIR results suggest that APU has been introduced into the resin matrix resin. Tensile test results show that the addition of appropriate APU can increase the elongation at break significantly, compared with neat epoxy. SEM results indicate that the fracture mechanism has changed from brittle to ductile, suggesting that the brittleness of the material has been overcome. DMA results show that modified materials have lower glass transition temperature (T_g) and lower cross‐linking density for shape memory function. Furthermore, the fold‐deploy shape memory tests prove that the materials possess excellent shape memory properties. They can be deformed into different shapes and recover their original shapes fully within 2 min at T_g, while they are hardly affected by ninefold‐deploy cycles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

交联型水性聚氨酯的合成与研究

采用聚醚多元醇、异佛尔酮二异氰酸酯IPDI、2,2-二羟甲基丙酸(DMPA)、三乙胺为主要原料,采用自乳化法合成一系列的水性聚氨酯乳液。考查了预聚温度和预聚时间、扩链时间和扩链温度对反应的影响;R值(n/n)、DMPA的用量和中和度对乳液性能的影响。结果显示,当预聚温度为60℃、预聚时间为60 min、扩-NCO-OH链温度为75℃、扩链时间为120 min时,可以保证反应的速率和生产周期;选择R=2、DMPA用量为3%、中和度为100%,可以制得稳定的、性能优异的水性聚氨酯乳液,可用于织物的防水透湿整理。()     

水性聚氨酯室温交联技术研究进展

介绍了近年来国内外水性聚氨酯室温交联技术的研究进展,并对这些交联体系及其交联机理作了较为详细的阐述。其包括9种室温交联方式,即:1羰基与酰肼基团的交联;2基于Michael加成反应的交联;3异氰酸酯基团的交联;4氮丙啶与羧基的交联;5环状碳酸酯与胺基的交联;6不饱和脂肪酸中双键的自氧化交联;7脂环族环氧基团与羧基的交联;8金属离子与羧基、磺酸基等螯合作用交联;9硅氧烷基团的水解缩聚交联。     

Effect of crosslinking on the surface free energy and surface reorganization of waterborne fluorinated polyurethane

To endow waterborne fluorinated polyurethanes (WFPUs), films with stable lower surface free energy and lower surface reorganization after the films contacted with water, a series of crosslinked WFPUs (CWFPUs) emulsions were prepared by adjusting the content of aziridine (AZ). The effect of crosslinking on the surface free energy, glass-transition temperature (T _g), water absorption, and surface composition of dry/hydrated WFPUs and CWFPUs films were studied by CAs test, dynamic mechanical analysis, water absorption measurements, and X-ray photoelectron spectroscopy. When the fluorine content was 0.5%, the surface free energy of the CWFPUs films modified by 0.4% AZ content (CWFPU-6-0.5-CK0.4) reached to the lowest value of 15.76 mN m⁻¹ which almost equaled to the surface free energy (15.45 mN m⁻¹) of the dry uncrosslinked films (WFPU-6-0.5). With the increasing of AZ content, the T _{g, hard} of hard segments of the CWFPUs films increased and the water absorption of the CWFPUs films decreased, which suggested the formation of the crosslinked network structures. The studies of the surface elements and groups composition of dry/hydrated WFPUs and CWFPUs both confirmed that the surface reorganization and the migration of fluorinated side chains were restricted by the crosslinked network structures. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47167.     

Effect of hydroxyl‐terminated poly(fluoroalkyl methacrylate) main‐chain length on the microphase separation of waterborne fluorinated polyurethane

Waterborne fluorinated polyurethanes (WFPUs) based on hydroxyl‐terminated poly(fluoroalkyl methacrylate)s (HTPFMAs) with different main‐chain lengths were synthesized. The structure of HTPFMA was characterized using ¹H NMR spectroscopy, measurements of hydroxyl values and gel permeation chromatography. The microstructures of WFPUs were investigated using Fourier transform infrared spectroscopy, which indicated that hydrogen bonding interactions in hard segments of WFPUs were enhanced by the introduction of HTPFMA and increased with increasing main‐chain length of HTPFMA. The results of X‐ray diffraction demonstrated that increasing the main‐chain length of HTPFMA resulted in an increase of crystallinity in hard segments. Differential scanning calorimetry revealed that the melting temperature of micro‐crystallites in hard segments and the microphase separation increased with an increase of HTPFMA main‐chain length. Dynamic mechanical analysis and scanning electron microscopy also confirmed that HTPFMA with longer main‐chain length can promote the extent of microphase separation of WFPUs between soft and hard domains. The mechanical properties of WFPUs were improved due to the increase of microphase separation with increasing HTPFMA main‐chain length. © 2018 Society of Chemical Industry     

丙烯酸酯改性水性聚氨酯的合成及应用研究

以异氰酸酯、聚醚多元醇及二羟甲基丙酸(DMPA)为主要原料,合成了水性聚氨酯(WPU)预聚体;然后采用扩链、交联和丙烯酸酯复合改性等方法制备了丙烯酸酯改性水性聚氨酯(PUA)。结果表明:水性PUA具有丙烯酸酯和聚氨酯(PU)的双重优点,而且其低温成膜性较好、综合性能较优、成本及VOC含量较低;由PUA配制的木器漆,其主要性能均达到HG/T36082-1999标准。     

水性聚氨酯压敏胶的合成及其性能表征

以异佛尔酮二异氰酸酯(IPDI)、聚醚多元醇(N220、N210)、二羟甲基丙酸(DMPA)和三羟甲基丙烷(TMP)为主要原料制得了环保交联型水性聚氨酯(WPU)压敏胶,讨论了n(-NCO)/n(-OH)比值、交联剂用量以及聚醚相对分子质量大小对该压敏胶性能的影响。研究结果表明,由N220合成的WPU压敏胶的初粘力优于由N210合成的WPU压敏胶;随着n(-NCO)/n(聚醚中-OH)比值的减小,压敏胶的初粘力提高,持粘力呈先降后增再降的趋势;适度的交联可以提高压敏胶的粘接强度;当n(-NCO)∶n(聚醚中-OH)为2.5∶1、n(TMP中-OH)∶n(聚醚中-OH)为1∶3.0时,压敏胶的综合性能优异,初粘力达到13号钢球,持粘力达到23.1h,180°剥离强度达到20.14N/(20mm)。     

水性聚氨酯的交联改性技术

介绍了提高水性聚氨酯耐水性,耐溶剂性和物理机械性能的交取改性技术及最新进展。     

Fourier transform infrared study of supramolecular polyurethane networks containing pyridine moieties for shape memory materials

Non‐covalent interactions are increasingly used in the molecular self‐assembly of well‐defined structures. In this study, a series of pyridine‐containing polyurethanes (PUPys) were synthesized with diisocyanates and pyridine derivatives. Fourier transform infrared spectroscopy was employed to identify the vibration frequencies and investigate the relationship of shape memory effect (SME) and hydrogen‐bonded supramolecular structure of the PUPys. The results show that a large fraction of strong hydrogen bonds are formed in the urethane group as well as in the pyridine ring. Moreover, the hydrogen bonding in the pyridine ring not only shows a response to a temperature stimulus in the PUPys, but is also responsive to moisture in N,N‐bis(2‐hydroxylethyl)isonicotinamine (BINA)/hexamethylene diisocyanate (HDI)‐based PUPys; the hydrogen bonds in the urethane group have a higher dissociation temperature and show little response to moisture absorption. Accordingly, the PUPys are expected to show thermally induced and moisture‐induced SMEs. Finally, the shape recovery process of films in the shape of flowers induced by temperature and moisture supports the idea that the PUPys could be used as thermally induced shape memory polymers (SMPs), and the BINA/HDI‐based PUPys could be used as moisture‐sensitive SMPs. Copyright © 2009 Society of Chemical Industry     

Mechanically strong shape memory polyurethane for water vapour permeable membranes

Water vapour permeable polymeric thin films possess significant importance in miscellaneous applications such as packaging, medical devices, controlled‐release systems, electronics and biosensors. In this work, a series of shape memory polyurethanes (SMPUs) were synthesized by a two‐step pre‐polymerization technique with variations in hard to soft segments and molecular weight of macroglycol. DSC, Fourier transform infrared spectra, dynamic TGA and tensile testing were carried out to characterize and evaluate the properties of these synthesized SMPUs. The effect of the soft segment and the molecular weight of macroglycol on the thermal properties, mechanical properties and water vapour permeability of the synthesized SMPUs were investigated to achieve a good water vapour permeable membrane. We found that the synthesized SMPUs demonstrated a good water vapour transmission rate of over 1460 g m^?2 day^–1 as well as robust mechanical properties with tensile strength 19.8 MPa indicating a promising permeable polymeric thin film for many potential applications, especially as protective clothing. © 2018 Society of Chemical Industry     

Effect of molecular weight on shape memory behavior in polyurethane films

Understanding the relationship between the number‐average molecular weight (M_n) and the shape memory behavior of polymers is crucial for a complete picture of their thermomechanical properties, and hence for the development of smart materials, and, in particular, in textile technology. We report here on the study of shape memory properties as a function of M_n of polymers. Shape memory polyurethanes (SMPUs) of different M_n were synthesized, with various catalyst contents or molar ratio(r = NCO/OH) in the composition. In particular, two types of SMPU, namely T_m and T_g types according to their switch temperature type, were synthesized to compare the influence of M_n on their shape memory behavior. X‐ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, and shape memory behavior results for the SMPUs are presented. The results indicate that the melting temperature (T_m), the glass transition temperature (T_g), the crystallinity, and the crystallizability of the soft segment in SMPUs are influenced significantly by M_n, before reaching a critical limit around 200 000 g mol^?1. Characterization of the shape memory effect in PU films suggests that the T_m‐type films generally show higher shape fixities than the T_g‐type films. In addition, this shape fixity decreases with increasing M_n in the T_g‐type SMPU, but the shape recovery increases with M_n in both types of SMPU. The shape recovery temperature, in contrast, decreases with M_n as suggested by the result of their thermal strain recovery. It is concluded that a higher molecular weight (M_n > 200 000 g mol^?1) is a prerequisite for SMPUs to exhibit higher shape recovery at a particular temperature. Copyright © 2007 Society of Chemical Industry     

蓖麻油改性聚醚型水性聚氨酯乳液的性能

以聚醚、甲苯二异氰酸酯(TDI)、一缩二乙二醇、蓖麻油为主要原料,二羟甲基丙酸(DMPA)为亲水扩链剂,三乙胺为中和剂制备了稳定的阴离子水性聚氨酯乳液(WPU),研究了NCO/OH摩尔比、DMPA及蓖麻油的加入量对WPU的耐水性、稳定性和力学性能的影响,结果表明:改性后的乳液具有较好的稳定性,适量的蓖麻油可提高胶膜的拉伸强度及耐水性。当聚醚与蓖麻油质量比为7︰3、DMPA为5%、NCO与OH摩尔比为1.3时,WPU综合性能最好。     

自交联水性聚氨酯-含氟丙烯酸酯乳液的制备及研究

以异佛尔酮二异氰酸酯(IPDI)、聚碳酸酯二醇(PCDL)、二羟甲基丁酸(DMBA)、1,4-丁二醇(BDO)、甲基丙烯酸羟乙酯(HEMA)为原料合成了双键封端的聚氨酯预聚体;以N-羟乙基丙烯酰胺(HEAA)作交联剂,配合甲基丙烯酸六氟丁酯(HFBMA)等单体进行乳液共聚,制备了自交联水性聚氨酯-含氟丙烯酸酯(FPUA)乳液。研究了HFBMA和HEAA用量对膜耐水性、热性能以及力学性能的影响。结果表明:PUA乳液的耐水性和疏水性随HFBMA用量的增加而增加;随着HEAA用量增加,胶膜的热稳定性增加,拉伸强度增加,伸长率下降;当胶膜中HFBMA质量分数为12%,且HEAA质量分数为2.6%时,乳液的粒径为128 nm,乳液的稳定性较好;胶膜的水接触角为107.6°,吸水率为4.5%,拉伸强度为25.6 MPa,断裂伸长率为268%,10%热失重温度299.6℃。     

水性聚氨酯粘接强度研究进展

介绍了国内外对提高水性聚氨酯(WPU)粘接强度的研究现状。详细阐述了WPU的分子链结构、共聚改性[包括环氧树脂(EP)改性、丙烯酸酯改性和有机硅改性]等对WPU粘接强度的影响,并对WPU今后的发展方向进行了展望。     

纳米SiO2/形状记忆聚氨酯复合材料的研究

在合成形状记忆聚氨酯(SMPU)的过程中加入经钛酸酯偶联剂表面处理的纳米SiO2粒子，制备了纳米SiO2／形状记忆聚氨酯复合材料。用FT-IR、DSC、SEM对其进行了分析，考察了它的形状记忆性能和力学性能。结果表明，偶联剂的用量对纳米粒子有很大影响，当钛酸酯用量为纳米粒子质量的80％时才能有效包敷好纳米粒子，而SMPU中只有包敷效果良好的纳米粒子，才能提高SMPU的形状回复温度及其力学性能，否则会使性能下降，而且偶联剂的引入对形状固定和形状稳定都有负面作用。     

支化型水性聚氨酯胶黏剂的合成及性能

采用异佛尔酮二异氰酸酯(IPDI)、聚四氢呋喃醚二醇2000(PTMG2000)为原料,二月桂酸二丁基锡、1,4-丁二醇和2,2-二羟甲基丙酸分别为催化剂、小分子扩链剂和亲水单体,制得水性聚氨酯预聚体(PPU);接着以丙烯酸甲酯、二乙醇胺和三羟甲基丙烷为原料合成了超支化聚(胺-酯)(HPAE);最后制备出不同HPAE含...     

聚酯型水性聚氨酯油墨连接料的研究

以聚酯二元醇、二异氰酸酯和二羟甲基丙酸(DMPA)为主要原料,合成了聚酯型水性聚氨酯(WPU)乳液。研究了聚酯二元醇的种类、R值[R=n(-NCO)/n(-OH)]和DMPA用量等对WPU乳液的附着力、稳定性和T型剥离强度等影响。结果表明:以Pol-356(由己二酸、乙二醇和1,4-丁二醇聚合而成)为聚酯二元醇、端羟基聚酯多元醇(Pol-350)为小分子扩链剂,当w(DMPA)=9%、R值为1.200～1.225时,制成的WPU乳液固含量高、储存稳定性好,其对非极性BOPP(双向拉伸聚丙烯)薄膜等具有相对较高的附着力和T型剥离强度。     

抗起毛起球整理用热反应型WPU的合成及应用

以异佛尔酮二异氰酸酯（IPDI）、聚多元醇为主要原料,以异丙醇为溶剂,合成了反应型水性聚氨酯整理剂,既保持了聚氨酯的弹性,又具有极好的反应活性,可以赋予织物各种功能,提高纺织品的附加价值。介绍了该类整理剂在纯棉针织物抗起毛起球整理中的应用。