硬段含量对水性聚氨酯性能的影响

以聚酯多元醇和异佛尔酮二异氰酸酯(IPDI)为主要原料，引入亲水单体二羟甲基丙酸(DMPA)，按不同配比合成了系列聚氨酯乳液。考察了硬段含量对乳液粒径、表观黏度、膜吸水性、硬度、力学性能的影响，并通过动态力学性能测试(DMA)研究了软段和硬段的玻璃化转变温度。结果表明：提高-NCP/-0H物质的量之比、DMPA用量均使聚氨酯中软段的玻璃化温度Tg(s)降低，硬段的玻璃化温度Tg(h)升高，△T值增加，软硬段相分离程度增加。随乙二胺用量的增加，会使软段玻璃化转变温度Tg(s)移向高温，软硬段相分离程度降低；硬段含量提高，胶膜硬度增加，拉伸强度增加，胶膜耐水性降低。     

环氧改性PPC基水性聚氨酯乳液的合成及应用

以聚碳酸亚丙酯二元醇(PPC)为软段,1,4-丁二醇(BDO)和甲苯二异氰酸酯(TDI)为硬段,二羟甲基丙酸(DMPA)为亲水扩链剂,三羟甲基丙烷(TMP)为交联剂,通过环氧树脂改性,制得一种新型的环氧改性水性聚氨酯乳液,用其制备的常温自干漆在金属底材上有良好的附着力和耐性。讨论了n(—NCO)/n(—OH)比值、DMPA用量、环氧树脂用量、中和剂和中和度等对乳液性能和贮存稳定性的影响,确定了最佳合成条件。     

聚氨酯乳液的电位及其稳定性

以聚氧化丙烯二醇、甲苯二异氰酸酯、二羟甲基丙酸、2-甲基丙二醇、三乙胺和多元胺为原料合成了一系列不同离子基团含量的聚氨酯乳液，并测定了乳液的ζ电位，以及高温、冻融、机械稳定性和抗电解质能力。     

生态合成革用高固含量水性聚氨酯乳液的合成

以异氟尔酮二异氰酸酯、六亚甲基二异氰酸酯、聚四氢呋喃二醇、聚己内酯二醇等为主要原料,以2,2-二羟甲基丁酸(DMBA)和N-60胺基磺酸盐作为亲水性扩链剂,合成了一系列高固含量水性聚氨酯乳液。分别考察了n(—NCO):n(—OH)、软段组成、扩链剂种类及用量对乳液固含量及性能的影响。结果表明:n(—NCO):n(—OH)为1.3:1.0,软段聚醚与聚酯的摩尔比为1:2,DMBA质量分数为1.5%,N-60胺基磺酸盐质量分数为0.2%时,合成的水性聚氨酯乳液固含量高、黏度低、稳定性好、综合性能优异,适合制备生态合成革。     

聚氨酯乳液的ζ电位及其稳定性

以聚氧化丙烯二醇，甲苯二异氰酸酯、二羟甲丙酸、２－甲基丙二醇、三乙胺和多元胺为原料合成了一系列不同离子基团含量的聚氨酯乳液，并测定了乳液的ζ电位，以及高温、冻融、机械稳定性和抗电解质能力。     

聚酯相对分子质量对嵌段聚氨酯弹性体形态与性能的影响

以聚１，４－丁二醇己二酸酯为软段，４，４‘－二苯基甲基二民盟氰酸酯和扩链剂丁二醇为硬段，经一步法合成了不同软段相对分子质量的ＰＢＡ型聚氨酯。借助ＤＳＣ法，Ｘ射线，ＴＥＭ法等对试样试样性能进行了分析。当ＰＢＡ相对分子质量从５００增加到２０００时，软段玻璃化转变温度则由－２２．９℃减小到－３９．７℃，微观相分离程度由０．１３增加到０．２７，ＰＢＡ型ＰＵ由无链段结晶变成含有许多软，硬段结晶，人而便拉伸强     

非离子型水性聚氨酯的制备及其涂膜表面性质研究

采用自乳化方法合成不同聚乙二醇(PEG)含量的非离子型水性聚氨酯乳液(WPU),并用傅里叶变换衰减全反射红外光谱(ATR-FTIR)、原子力显微镜(AFM)、接触角测量仪研究不同PEG含量对WPU涂膜表面性质的影响。结果表明:随着PEG含量的增加,WPU硬段与硬段之间氢键作用减弱,表现出硬软段微相分离程度降低;同时,WPU涂膜表面甲基含量增加,表面粗糙度下降,表现出涂膜表面能下降,水接触角增大。     

软段含离子的水性聚氨酯乳液

南京大学高分子科学与工程系以二羟甲基丙酸 (ＤＭＰＡ)为起始剂 ,由己内酯开环聚合合成了含羧基的聚丙内酯二醇 ,并以此为软段 ,与ＴＤＩ在氮气流中反应 3ｈ ,与三乙胺反应1 0ｍｉｎ ,然后再进行乳化和去除溶剂 ,制得一类新型的阴离子型聚氨酯乳液。该乳液的外观为透明溶液 ;固含量 2 0 % ;ｐＨ值为 7;羧基质量分数 (聚合物中 ) 4.3% ;乳液的冷热循环稳定性 ,90℃ 5ｈ ,0℃ ,5ｈ ,往复 1 0次 ,无沉淀 ;成膜后拉伸强度46.69ＭＰａ ;断裂伸长率 590 % ;杨氏模量 388.8。显然 ,由於其聚合物含有羧基的聚己内酯二醇的软段 ,它不仅与硬段含离子…     

基于液化二羟甲基丙酸的水性聚氨酯的结构与性能

以液化改性二羟甲基丙酸(L-DMPA)为亲水性软段,制备了不含N-甲基吡咯烷酮(NMP)助溶剂的水性聚氨酯(WPU-A),对其结构与性能进行了表征,并与以二羟甲基丙酸(DMPA)为亲水扩链剂的水性聚氨酯(WPU-B)进行比较。结果表明,WPU-A乳液的粒径(71 nm)明显小于WPU-B乳液的粒径(195 nm),说明引入L-DMPA后有利于聚氨酯在水中的分散,提高了乳液的稳定性。同时,对样品的拉伸强度和断裂伸长率影响不大。DSC、DMA研究表明,引入L-DMPA后,由于软段中含有离子基团,使得软段分子间相互作用加强,从而导致软段的结晶度和物理交联密度降低。     

阳离子型聚氨酯乳液的合成及性能研究

本文用丙酮法,以聚酯二醇、聚醚二醇与1,6-已二异氰酸酯(HDI)为基材,N—甲基二乙醇胺为扩链剂,酸类为中和剂,合成了离子化程度不同的阳离子自乳化热塑性聚氮酯(简称TPU)水乳液。并对乳液的粒径、流变性以及乳胶膜的动态力学性能进行了初步的探讨。结果表明:乳液的粒径随离子度的增加而减小;改变TPU分子链中软段的结构,乳液的流性指数n,可在小于1到大于1的范围内调节;TPU的玻璃化转变温度,随软段结构中聚酯酯二醇含量的提高向高温方向移动。     

硬段对PCDL型水性聚氨酯的结构与性能的影响

以聚碳酸酯二元醇(PCDL)为软段,分别以异氟尔酮二异氰酸酯(IPDI)、甲苯二异氰酸酯(TDI)、二苯基甲烷二异氰酸酯(MDI)、六亚基二异氰酸酯(HDI)为硬段,采用丙酮法制备了四种不同硬段组成的PCDL型水性聚氨酯(WPU).综合对比,研究了硬段类型对PCDL型WPU结构与性能的影响.结果表明,芳香族WPU的力学...     

The effect of soft‐segment structure on the properties of novel thermoplastic polyurethane elastomers based on an unconventional chain extender

Thermoplastic polyurethane elastomers (TPUs) are now widely used because of their excellent properties that include high tensile and tear strength, and good abrasion, impact and chemical resistance. TPUs are multiblock copolymers with alternating sequences of hard segments composed of diisocyanates and simple diols (chain extenders) and soft segments formed by polymer diols. Commonly used hard segments for TPUs are derived from 4,4′‐diphenylmethane diisocyanate (MDI) and aliphatic diols. The aim of our research was to examine the possibility of obtaining TPUs with good tensile properties and thermal stability by using an unconventional aliphatic‐aromatic chain extender, containing sulfide linkages. Three series of novel TPUs were synthesized by melt polymerization from poly(oxytetramethylene) diol, poly(ε‐caprolactone) diol or poly(hexane‐1,6‐diyl carbonate) diol of number‐average molecular weight of 2000 g mol^?1 as soft segments, MDI and 3,3′‐[methylenebis(1,4‐phenylenemethylenethio)]dipropan‐1‐ol as a chain extender. The structure and basic properties of the polymers were examined using Fourier transfer infrared spectroscopy, X‐ray diffraction, atomic force microscopy, differential scanning calorimetry, thermogravimetric analysis, Shore hardness and tensile tests. It is possible to synthesize TPUs from the aliphatic‐aromatic chain extender with good tensile properties (strength up to 42.6 MPa and elongation at break up to 750%) and thermal stability. Because the structure of the newly obtained TPUs incorporates sulfur atoms, the TPUs can exhibit improved antibacterial activity and adhesive properties. Copyright © 2011 Society of Chemical Industry     

PCDL含量对混和软段的PUE相分离和阻尼性能的影响

以甲苯二异氰酸酯（TDI）、1,4-丁二醇（BDO）为硬段,聚碳酸酯二醇（PCDL）和聚醚二醇（PPG）混合物为软段,采用预聚体法制备了不同软段组成的聚氨酯弹性体（PUE）。采用DSC、FT—IR和DMA等分析手段研究了PCDL含量对PUE的微相分离程度和阻尼性能的影响。结果表明,随着软段中PCDL含量的增加,PUE中氨酯羰基的氢键化程度减小,相分离程度减小,而且PUE的储能模量随着PCDL含量的增加而减小;与单一组分软段的PUE相比较,混合软段的PUE具有相对较好的阻尼性能。     

三官能度聚醚型聚氨酯弹性体的力学性能研究

以三官能度的聚醚多元醇、1,4-丁二醇和二苯基甲烷二异氰酸酯(MDI)为主要原料合成了聚氨酯弹性体。研究表明,硬段质量分数超过50%以后,伸长率降低,交联时间对聚氨酯(PU)弹性体整体的力学性能影响不大。在保持异氰酸酯指数为1.0和MDI含量不变的条件下,把1,4-丁二醇和聚醚多元醇的羟基摩尔比提高到1.50:0.33,材料的力学性能最佳。随着交联时间的增加,拉伸强度及硬度先增大后减小,伸长率呈减小的趋势。     

Thermoplastic polyurethanes with isosorbide chain extender

Isosorbide, a renewable diol derived from starch, was used alone or in combination with butane diol (BD) as the chain extender in two series of thermoplastic polyurethanes (TPU) with 50 and 70% polytetramethylene ether glycol (PTMEG) soft segment concentration (SSC), respectively. In the synthesized TPUs, the hard segment composition was systematically varied in both series following BD/isosorbide molar ratios of 100 : 0; 75 : 25; 50 : 50; 25 : 75, and 0 : 100 to examine in detail the effect of chain extenders on properties of segmented polyurethane elastomers with different morphologies. We found that polyurethanes with 50% SSC were hard elastomers with Shore D hardness of around 50, which is consistent with assumed co‐continuous morphology. Polymers with 70% SSC displayed lower Shore A hardness of 74–79 (Shore D around 25) as a result of globular hard domains dispersed in the soft matrix. Insertion of isosorbide increased rigidity, melting point and glass transition temperature of hard segments and tensile strength of elastomers with 50% SSC. These effects were weaker or non‐existent in 70% SSC series due to the short hard segments and low content of isosorbide. We also found that the thermal stability was lowered by increasing isosorbide content in both series. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42830.     

聚氨酯纯硬段模拟化合物的研究

用乙二醇、1,4-丁二醇、三缩四乙二醇和甲苯二异氰酸酯为原料 ,以二正丁胺为封端剂合成了几种不同结构的聚氨酯纯硬段模拟化合物。并用FT -IR、DSC、TG、WAXD对化合物的结构进行了研究。结果表明 ,化合物有结晶 ,纯硬段模拟化合物的降解温度与二醇的结构无关。     

Thermoplastic polyurethane elastomers based on polycarbonate diols with different soft segment molecular weight and chemical structure: Mechanical and thermal properties

A series of thermoplastic polyurethane elastomers based on polycarbonate diol, 4,4′‐diphenylmethane diisocyanate and 1,4‐butanediol was synthesized in bulk by two‐step polymerization varying polycarbonate diol soft segment molecular weight and chemical structure, and also hard segment content, and their effects on the thermal and mechanical properties were investigated. Dynamic mechanical analysis termogravimetric analysis, differential scanning calorimetry, Fourier transform infrared‐attenuated total reflection spectroscopy and mechanical tests were employed to characterize the polyurethanes. Thermal and mechanical properties are discussed from the viewpoint of microphase domain separation of hard and soft segments. On one hand, an increase in soft segment length, and on the other hand an increase in the hard segment content, i.e., hard segment molecular weight, was accompanied by an increase in the microphase separation degree, hard domain order and crystallinity, and stiffness. In phase separated systems more developed reinforcing hard domain structure is observed. These hard segment structures, in addition to the elastic nature of soft segment, provide enough physical crosslink sites to have elastomeric behavior. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers     

Segmented poly(urethane‐urea) elastomers based on polycaprolactone: Structure and properties

A series of segmented poly(urethane‐urea) polymers have been synthesized varying the hard segments content, based on the combination of polycaprolactone diol and aliphatic diisocyanate (Bis(4‐isocyanatocyclohexyl)methane), using diamine (1,4‐Butylenediamine) as the chain extender. The microstructure and properties of the material highly depend on the hard segments content (from 14 to 40%). These PUUs with hard segment content above 23% have elastomeric behaviors that allow high recoverable deformation. The chemical structure and hydrogen bonding interactions were studied using FTIR and atomic force microscopy, which revealed phase separation that was also confirmed by DSC, dynamic‐mechanical, and dielectric spectroscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Rheological and thermal properties of glycidyl azide polyol‐based energetic thermoplastic polyurethane elastomers

The purpose of this study was to investigate the effects of polyol on glycidyl azide polyol (GAP)‐based energetic thermoplastic polyurethane elastomers (ETPEs). Briefly, a series of GAP/polyol‐based ETPEs (GAP/polyol ETPEs) with different copolyol ratios and hard segment contents were synthesized using GAP‐diol with common polyol and 4,4‐methylenebis(phenylisocyanate)‐extended 1,5‐pentanediol as soft and hard segments, respectively, by solution polymerization in dimethylformamide. The three types of polyols used were poly(tetramethylene ether) glycol (PTMG), polycarbonate‐diol (PCL‐diol) and polycaprolactone‐diol (PCD‐diol). The synthesized GAP/polyol ETPEs were identified and characterized using Fourier transform infrared and ¹H NMR spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and rheometric mechanical spectrometry. For GAP/PCL ETPEs with lower hard segment content, DSC results showed that the GAP segment failed to interact with either the PCL segment or PCL melting. In addition, the results of DMA showed that the presence of PCL segments in ETPEs improved the storage modulus below the melting temperature of the PCL block. Further, the crystalline PCL segments were attributed to reinforcing the ETPEs in a manner similar to that of the hard domain. As the hard segment content increased in the GAP/polyol ETPEs, both GAP/PTMG ETPEs and GAP/PCL ETPEs exhibited microphase separation transitions, while rheological experiments demonstrated a sudden decrease in complex viscosity in neighboring microphase separation transitions. © 2012 Society of Chemical Industry     

聚氨酯乳液的改性及其应用研究

用丙酮法合成了固含量为35%的聚氨酯成膜乳液。主要考查了复合型软段对聚氨酯成膜乳液及其胶膜性能的影响,并考查了乳液在水性印刷油墨中的应用。结果表明,亲水基团-COOH质量分数达到1.5%,能保证乳液的力学稳定性;随着不同聚多元醇复配比例的变化,乳液的稳定性和黏度、聚氨酯胶膜的力学性能以及吸水性均呈规律性变化,所制备的水性聚氨酯油墨对PET薄膜的附着力好。