含氟丙烯酸酯微乳液改性水性PUA

以全氟辛酸铵/十二烷基硫酸钠为复合乳化剂,过硫酸铵为引发剂,合成了丙烯酸丁酯(BA)与甲基丙烯酸-2-(全氟壬烯氧基)乙酯(FNEMA)共聚物微乳液(粒径为72 nm),并将其与聚氨酯脲-丙烯酸酯(PUA)水分散液进行了共混改性.结果表明,在基本上不影响改性PUA膜吸水率的前提下,改性PUA水分散液的表面张力明显下降,改性膜表面的疏水性显著增强.     

超支化聚合物改性水性聚氨酯的制备与性能研究

以多官能度聚酯二元醇为软段、HBP(端羟基超支化聚酯)为改性交联剂、IPDI(异佛尔酮二异氰酸酯)和DMPA(二羟甲基丙酸)为硬段,采用原位聚合法制备出稳定的HBPU(超支化水性聚氨酯分散液),并对其结构和性能进行了分析。研究结果表明:经羟基比率为1∶6的HBP改性后,相应HBPU的表面张力降低,说明其对非极性基材的浸润性增强;由于WPU(水性聚氨酯)大分子链之间形成了交联网状结构,故HBPU胶膜的力学性能、硬度和热性能等得到明显改善。     

负离子型聚氨酯离聚体水分散过程的相反转

用异佛尔酮二异氰酸酯、聚己二酸新戊二醇酯和二羟甲基丙酸（DMPA）合成了负离子型聚氨酯离聚体．研究了该类离聚体在水分散过程中的相反转变化,讨论了DMPA质量分数和水分散温度对相反转过程的影响。结果表明,DMPA质量分数增加或水分散温度提高,可使相反转所需的时间缩短,分散液粒子粒径变小,粒径分布更均匀,黏度增大。水分散温度的作用较DMPA更为明显。差示扫描量热分析表明,水分散过程破坏了亲水性硬链段的有序性。傅里叶变换红外光谱分析表明,聚氨酯水分散液用乙二胺扩链后．脲羰基的氢键化程度随DMPA质量分数的增加、水分散温度的提高而提高。     

紫外光固化水性聚氨酯丙烯酸酯分散液流变行为

用甲苯二异氰酸酯、聚己二酸新戊二醇酯多元醇、二羟甲基丙酸(DMPA)和甲基丙烯酸羟乙酯合成了紫外光固化聚氨酯丙烯酸酯(PUA)水分散液。该预聚物组成通过FTIR和^1H-NMR进行了表征,并对其水分散液的流变行为进行了研究。结果表明,随预聚物中DMPA质量分数的增加,分散液由牛顿流体转变为非牛顿流体。当DMPA质量分数为6．68％时,PUA水分散液的粒径为40～70nm,ζ电位为-66．00mV,黏流活化能为59．08J／mol。     

以二聚脂肪酸聚酯二元醇为软段合成水性聚氨酯-脲

以C36二聚脂肪酸聚酯二元醇为软段,合成了一系列贮存稳定性优异的聚氨酯-脲(PUU)水分散液。与由己二酸聚酯二元醇制备的PUU水分散液相比,这类PUU水分散液的粒径减小,成膜后的耐水性和力学性能明显提高,其中硬段质量分数为35%的水分散液(DPU 35)成膜后的吸水率最低,仅为1. 3%。进一步在DPU 35中添加少量的含氟聚丙烯酸酯乳液,发现水在这种改性PUU膜表面的接触角上升到96°,表现出良好的疏水性,材料的力学性能也更高。     

含氟丙烯酸醋微乳液改性水性PUA

以全氟辛酸铵／十二烷基硫酸钠为复合乳化剂，过硫酸铵为引发剂，合成了丙烯酸丁酯(BA)与甲基丙烯酸-2-(全氟壬烯氧基)乙酯(FNEMA)共聚物微乳液(粒径为72nm)，并将其与聚氨酯脲-丙烯酸酯(PUA)水分散液进行了共混改性。结果表明，在基本上不影响改性PUA膜吸水率的前提下，改性PUA水分散液的表面张力明显下降，改性膜表面的疏水性显著增强。     

水性光致变色聚氨酯的制备及其性能研究

采用2种不同方式将螺吡喃与聚氨酯相结合制备水性光致变色聚氨酯,一种方式是将合成的水性聚氨酯分散液与螺吡喃的乙醇溶液进行物理共混,得到共混光致变色聚氨酯乳液(BPPU);另一种方式是将有机光致变色螺吡喃分子作为终端引入聚氨酯预聚体中,水分散得到水性光致变色聚氨酯乳液(CPPU)。利用紫外-可见分光光度计分别研究了BPPU乳液、CPPU乳液及其成膜的光致变色性能,并利用SEM观察了共混、共聚薄膜的微观结构。结果发现:BPPU乳液不稳定,涂膜中螺吡喃成分容易聚集;CPPU乳液和膜均具有良好的光致变色性能,涂膜中螺吡喃组分分布较均匀。     

用于压裂返排液超支化交联剂的合成及其性能评价

以聚乙烯亚胺、乙二醇、多元醇、硼砂为主要原料合成超支化聚氨基硼和四乙烯五胺硼酸酯交联剂,并对产物进行结构表征及压裂返排液重复配液性能测试。将0.35%羟丙基胍胶溶液与合成的聚超支化氨基硼交联剂以100∶0.4交联比交联,形成的压裂液冻胶体系在7 min左右达到压裂液黏度要求,在80℃、170 s^-1连续剪切70 min时压裂液黏度在100 mPa·s左右,满足行业标准要求(黏度>50 mPa·s)。对此过程进行破胶,破胶液黏度最终为3.2 mPa·s,破胶液中的残渣浓度为198 mg/L。与之相比,四乙烯五胺硼酸酯交联剂体系不能满足返排液的配液要求。用破胶后的压裂返排液再次进行配液,将温度设置到80℃、170 s^-1不间断剪切70 min,将压裂液中的黏度调整至50 mPa·s以上,破胶液黏度为3.4 mPa·s。该交联剂使压裂返排液能重复利用。这对节约水资源、降低环境污染具有广阔的工业化前景。     

菱镁板吸塑用聚氨酯胶粘剂的研制

选用低聚物二元醇、二异氰酸酯、二元胺及硅烷偶联剂等合成了菱镁板吸塑聚氯乙烯(PVC)所需的聚氨酯胶粘剂。讨论了多元醇及二异氰酸酯种类、异氰酸酯指数、偶联剂加入方法和用量及胶粘剂相对分子质量等对聚氨酯胶粘性能的影响。结果表明,以聚酯多元醇(PNBA)、甲苯二异氰酸酯(TDI)、扩链剂(IPDA)和偶联剂(KH-550)等原料合成的聚氨酯胶粘剂性能优异,相对分子质量为25 000~40 000,黏度为200 mPa.s~600 mPa.s(固含量30%)。将其喷涂于菱镁板上,真空吸塑PVC后,初黏力大,24 h后终黏剥离强度可达到4.1 N/mm,已达到菱镁板或PVC的破坏程度,满足了使用需要。     

水性聚氨酯分散液的研究进展

评述了水性聚氨酯分散液的作用和重要性,综述了水性聚氨酯分散液的研究进展,对水性聚氨酯分散液的合成制备方法进行了归纳总结,认为在制备水性聚氨酯过程中,同时利用异氰酸酯基和不饱和双键的反应活性,形成互穿聚合物网络体系是目前合成制备水性聚氨酯分散液的主要思路和方法,最后,对水性聚氨酯分散液的应用发展趋势进行了展望。     

脂肪族水性聚氨酯脲的改性研究

采用原位聚合法,通过聚醚多元醇、异佛尔酮二异氰酸酯和二羟甲基丙酸反应合成聚氨酯预聚体,以有机硅单体和乙二胺为扩链剂,得到有机硅改性的脂肪族水性聚氨酯脲分散液.改性后的水分散液呈蓝光透明或乳白色,且稳定性良好.与未改性聚氨酯脲相比,改性后聚氨酯脲水分散液的粒径有所增大,但粒径分布基本不变.改性水分散液成膜后的热稳定和冻融...     

Electrospinning of polyurethane fibers

A segmented polyurethaneurea based on poly(tetramethylene oxide)glycol, a cycloaliphatic diisocyanate and an unsymmetrical diamine were prepared. Urea content of the copolymer was 35 wt%. Electrospinning behavior of this elastomeric polyurethaneurea copolymer in solution was studied. The effects of electrical field, temperature, conductivity and viscosity of the solution on the electrospinning process and morphology and property of the fibers obtained were investigated. Results of observations made by optical microscope, atomic force microscope and scanning electron microscope were interpreted and compared with literature data available on the electrospinning behavior of other polymeric systems.     

Synthesis and characterization of novel optically active poly(urethane urea)s: Effect of left/right rotation conformation

Helical R/S‐poly(urethane urea)s (R/S‐HPUUs) were synthesized successfully with R/S‐1,1′‐binaphthyl‐2′,2‐diol, toluene 2,4‐diisocyanate, and 1,4‐diaminobenzene by a simple hydrogen‐transfer addition reaction. The structure and optical properties of R/S‐HPUUs were investigated systematically with Fourier transform infrared spectroscopy, ¹H‐NMR spectra, absorption and circular dichroism, thermogravimetry, differential scanning calorimetry, and X‐ray diffraction measurements. Fourier transform infrared spectra showed that all the ? NH and carbonyl groups in R/S‐HPUUs were hydrogen‐bonded. R‐HPUU and S‐HPUU were two enantiomorphs with wonderful mirror‐image symmetry according to circular dichroism spectroscopy analysis. R/S‐HPUUs exhibited optical activity, and the optical rotations were +54.7 and ?60.7°, respectively. R/S‐HPUUs showed excellent thermal stability because of the plane‐bifurcated interchain hydrogen bonds and helical stereostructures according to thermogravimetry, differential scanning calorimetry, and X‐ray diffraction analysis. Moreover, the left‐handed rotation was more stimulative for the construction of hydrogen bonds than the right‐handed rotation, so S‐HPUU showed higher thermal stability and better crystallizability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Distribution of hydrophilic monomer units and its effect on the property of the water dispersion of polyurethaneurea anionomer

Water dispersion of polyurethaneurea anionomer based on polyurethane synthesized by using “one‐step process” and water dispersion of polyurethaneurea anionomer based on polyurethane synthesized by using “two‐step process” were prepared. Spectra of ¹³C‐NMR proved that the distribution of the hydrophilic monomer units along the macromolecular chain resulted from the latter process was more uniform than that by the former process. Uniform distribution of hydrophilic monomer units led to smaller average size and polydispersity of the polyurethaneurea particles dispersed in water, as well as higher stability of the water dispersion. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 634–640, 2007     

Preparation,characterization, and properties of silicate/polyurethaneurea composites based on dipropylene glycol dibenzoate

The silicate/polyurethaneurea composites based on dipropylene glycol dibenzoate were prepared via a room‐temperature‐cured process. Characterization of the composites was accomplished using scanning electron microscope, X‐ray diffraction, Fourier transformation infrared spectrum, and Raman spectroscopy, and the mechanism, mechanical properties and stability were discussed in detail. The obtained results indicated that a durable silicate/polyurethaneurea composite with inorganic‐organic network structure had been successfully prepared. The composites were thermally stable below 210°C and the compressive and flexural strength of the material could reach 42.6 and 29.2 MPa after curing for 6 h, respectively. POLYM. COMPOS., 37–43, 2016. © 2014 Society of Plastics Engineers     

Mechanical and thermal properties of UV cured mixtures of linear and hyperbranched urethane acrylates

The properties of urethane acrylate resin mixtures based on the linear and hyperbranched aliphatic polyesters were examined. Linear polyester was synthesized from neopentil glycol and adipic acid. Hyperbranched polyester of the third generation was synthesized from 2,2-bis(hydroxymethyl)propionic acid and di-trimethylol propane. The modification of 60% of hyperbranched aliphatic polyester OH end groups was carried out with isononanoic acid or with soybean fatty acids. Two hyperbranched urethane acrylates, with the same degree of acrylation, and one linear urethane acrylate were obtained by reaction of appropriate polyester and isophorone diisocyanate and 2-hydroxyethyl acrylate. The influence of added amount of HUA and nature of non-acrylic end groups on the rheological, mechanical and thermal properties of the uncured and UV cured mixtures diluted with 20 wt.% hexanediol diacrylate was examined. The nature of non-acrylic end groups have great effect on the interaction between linear and hyperbranched urethane acrylates, which further has a crucial influence on the examined properties of uncured and UV cured mixture samples.     

可再生原料为交联剂制备水性聚氨酯脲

以二苯基甲烷二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)为硬段,聚氧化丙烯二元醇(GE210)为软段,乙二胺(EDA)为扩链剂,制备了具有良好分散性的阴离子水性聚氨酯脲(PUU)分散液。并用可再生的氧化玉米淀粉对其进行了交联改性。测试结果表明,加入氧化交联淀粉后,水性PUU分散液的表面张力增加,成膜后的力学性能得到改善。同时随氧化淀粉用量的增大,水性PUU膜的拉伸强度也逐渐增大。     

Separation of phenol from aqueous solution by membrane pervaporation using modified polyurethaneurea membranes

Hydroxy‐terminated polybutadiene‐based porous and nonporous polyurethaneurea membranes were prepared and used to study the phenol separation efficiency from dilute aqueous solution. The porosity was developed by incorporation of lithium chloride in polymer matrix with subsequent leaching of the same in hot water. The porous membrane showed higher phenol flux over that of nonporous membrane. Permeate containing about 97 wt % phenol was obtained from feed containing 7 wt % phenol, when pervaporation was carried out with porous polyurethaneurea membrane at 75°C. The activation energies for diffusion, permeation, and pervaporation were calculated from Arrhenius plots. From the activation energy values, it was observed that the pervaporation process became easier with increased phenol concentration in the feed and porosity of the membrane used. The membrane boundary resistance was observed to decrease with increase in temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1857–1865, 2006     

A polyamide thin-film composite membrane modified by Michael addition grafting of hyperbranched poly(amine ester)

In this work polyamide thin-film composite membrane (TFC) surface modified via Michael addition grafting of a hydrophilic hyperbranched poly(amine ester). For this purpose, amine-rich polyamide layer formed by interfacial polymerization on a polyethersulfone support, and then acrylated hyperbranched poly(amine ester) (AC-HBPAE) was used as grafting moiety. The membrane surface was characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM) and water contact angle techniques. Field emission scanning electron microscopy (FE-SEM) was used to evaluate surface and cross-section morphology of samples. Filtration performances and bio-fouling resistance were also studied using a nanofiltration cell. Surface chemical composition and contact angle indicated the successful grafting of acrylated poly(amine ester) to the membrane surface. The results also indicated there is a solid relationship between acrylation percentage of hyperbranched polymer and membrane properties such as fouling resistance. A uniform and hydrophilic surface observed for TFC membrane modified with 5% acrylated hyperbranched poly(amine ester).     

Dynamic mechanical behavior and nanostructure morphology of hyperbranched‐modified polypropylene blends

Polypropylene (PP) was modified utilizing two types of polyesteramide‐based hyperbranched polymers (amphiphilic PS and hydrophilic PH). A maleicanhydride‐modified PP (PM) was used as a reactive dispersing agent to enhance the modification by grafting the hyperbranched polymers onto the PP chains. Pure PP, two different non‐reactively modified samples, i.e. excluding PM, and two different reactively modified samples, i.e. including PM, were studied. Investigating the morphology of the samples was performed by scanning electron microscopy. To follow the effect of the modification on the dynamic mechanical properties, dynamic mechanical analysis experiments both in the melt (rheometric mechanical spectrometry) and in solid state (dynamic mechanical thermal analysis) were carried out. In the next step, the nanocrystalline structure of the samples was studied by small angle X‐ray scattering (SAXS) in two different modes, i.e. static and recrystallization. Hundreds of SAXS patterns were analyzed automatically using procedures written in PV‐WAVE image‐processing software. The chord distribution function (CDF) was calculated and the long period (l_p) of the crystal lamellae was extracted from the CDFs. The rheometric mechanical spectrometry results show that both hyperbranched polymers decrease complex viscosity η^* and enhance liquid‐like behavior. This happens more significantly when PM is included. The dynamic mechanical thermal analysis results reveal that T_g decreases when PS and PH are added. In the reactively modified samples this reduction is compensated most probably because of the crosslinked structure formed through the grafting reaction between the hyperbranched polymers and PM. Such structure is confirmed by SAXS data and calculated CDFs in the recrystallization mode. Static SAXS data also show enhancement in the crosshatched morphology of the crystalline lamellae of PP for reactively modified samples compared with non‐reactively modified samples. © 2013 Society of Chemical Industry