阳离子水性聚氨酯的合成与性能

采用不同聚合工艺对5种聚酯或聚醚二元醇、4种二异氰酸酯与N.甲基二乙醇胺亲水扩链剂合成阳离子水性聚氨酯进行了研究.结果表明,多元醇中加入亲水扩链剂后再加入多异氰酸酯进行加成聚合的工艺有较好的适用性,可制备稳定的阳离子水性聚氨酯.在35℃下进行水分散所得阳离子聚氨酯的乳液性能和膜力学性能好于70℃水分散的聚氨酯,其中拉伸强度最大可提高3倍以上.对不同亲水扩链剂含量和硬段含量的阳离子水性聚氨酯的研究表明,硬段含量达到30%(ω)以上时,亲水扩链剂用量增加,乳液的粒径变小,稳定性增加,聚氨酯膜的拉伸强度提高.由热性能分析可知,硬段含量达40%(ω)以上时,水性阳离子聚氨酯膜中的软、硬段有序结构被破坏,而其玻璃化转变温度在15℃以上.     

硬段阻燃改性水性聚氨酯的研究

以聚醚210(N-210)、异佛尔酮二异氰酸酯(IPDI)为基本单体,以FRC-5作为扩链剂,用硬段改性的方式将阻燃元素N、P引入到水性聚氨酯中,合成了一系列不同程度改性的阻燃水性聚氨酯。研究了FRC-5的用量对水性聚氨酯阻燃性能、热性能的影响。结果表明,用FRC-5进行扩链可以提高水性聚氨酯的阻燃性和热稳定性。     

偶联剂改性水性聚氨脂木器涂料

以甲苯二异氰酸酯（TDI）、聚醚二醇（N210）、二羟甲基丙酸（DMPA）为基本原料,在无溶剂的条件下,利用硅烷偶联剂通过合成和扩链的方法改性水性聚氨酯,制得了一系列不同含量硅烷偶联剂改性的水性聚氨酯乳液.性能测定表明：以此乳液再配以其他助剂制得的水性聚氨酯建筑用木器涂料,具有优异的粘附力、耐水性和力学性能.     

不同软链段对水性聚氨酯性能的影响

以低聚物多元醇、IPDI(异佛尔酮二异氰酸酯)、亲水扩链剂DMPA(2,2-二羟甲基丙酸)和成盐剂三乙胺为主要原料,合成一组软段成分不同的水性聚氨酯乳液。通过测定水性聚氨酯乳液的固含、黏度、结构,以及水性聚氨酯胶膜的耐水性、力学性能、T型剥离强度等,对比了不同类型软段对乳液及胶膜性能的影响。研究结果表明:由含6个碳的聚酯多元醇为软段合成的水性聚氨酯的黏度、耐水性、机械强度、T型剥离强度等数据较好。     

MDI体系聚氨酯弹性体的力学性能研究

考察了多元醇种类、扩链交联剂配比及合成工艺等因素对MDI体系聚氨酯弹性体力学性能的影响。结果表明,使用聚酯类多元醇合成的聚氨酯弹性体力学性能较好;使用半预聚物法合成的聚氨酯弹性体较使用两步法合成的聚氨酯弹性体综合性能优异;扩链交联剂种类及硬段含量对聚氨酯弹性体力学性能起重要作用。     

双组分遇水膨胀聚氨酯弹性体的性能研究

采用预聚物法合成遇水膨胀聚氨酯弹性体,考察了多元醇并用、硬段含量改变、扩链剂并用及配比变化等对聚氨酯弹性体力学性能与遇水膨胀性能的影响。实验发现,多元醇配比以及硬段含量对聚氨酯力学性能和亲水性能有重要影响,扩链剂种类与配比对聚氨酯吸水膨胀性能有重要影响。     

水性聚氨酯胶粘剂的合成与性能研究

采用芳香族聚酯二元醇与二异氰酸酯反应合成了一系列水性聚氨酯胶粘剂,探讨了影响水性聚氨酯稳定性、机械性能及热性能等的有关因素.研究发现用芳香族聚酯二元醇与TDI/HDI合成的水性聚氨酯乳液有较好的稳定性,当控制NCO/OH物质的量比为1.4左右,扩链剂EDA的加入量约为3%时,水性聚氨酯胶粘剂有较好的综合性能.     

磺酸型水性聚氨酯分散液的制备方法与性能

叙述了磺酸型水性聚氨酯分散液的分散性、固含量以及胶膜性能,除与低聚物二元醇、二异氰酸酯、扩链剂种类及合成工艺有关外,与磺酸根在聚氨酯大分子中的引入方式密切相关.从磺酸根不同引入方式,即磺酸根是从链端引入还是在链上引入,链上引入又分软段引入和硬段引入,详细介绍了不同引入方式和制备磺酸型水性聚氨酯分散液的工艺及性能.     

超支化水性聚氨酯共混改性纳米SiO_2水性聚氨酯的制备及性能研究

采用异佛尔酮二异氰酸酯(IPDI)、聚丙二醇(PPG-2000)和PPG-纳米SiO_2溶胶为原料合成聚氨酯预聚体,用2,2-二羟甲基丙酸(DMPA)作亲水扩链剂并用1,4-丁二醇(BDO)、三羟甲基丙烷(TMP)作小分子扩链剂进一步提高相对分子质量,再用乙酸酐封端的超支化水性聚氨酯(AWHBPU)进行共混改性,采用内乳化法制备了超支化水性聚氨酯共混改性纳米SiO_2水性聚氨酯。研究了超支化水性聚氨酯共混改性纳米SiO_2水性聚氨酯乳液的粒径及稳定性、黏度以及胶膜的热性能和力学性能。结果表明,AWHBPU含量4%的乳液体系较稳定;随着AWHBPU的引入,乳液黏度先减小后增大,当AWHBPU添加量为4%时,乳液黏度最小为66.55 mPa·s;当AWHBPU添加量为6%时,试样的最大拉伸强度可达到18.92MPa。     

偶联剂改性水性聚氨酯建筑用木器涂料

目前水性聚氨酯木器涂料还存在耐水性不强，与基材的粘附力不够强等缺点，较大程序地影响了它的推广应用。本文作者侯孟华、刘伟区等在无溶剂的条件下，利用氨基硅烷偶联剂通过溶液和扩链两种不同的方法改性水性聚氨酯，制得了一系列不同含量硅烷偶联剂改性的水性聚氨酯乳液。这种乳液再配以其它助剂制得的水性聚氨酯建筑用木器涂料，具有优异的粘附力、力学性能和耐水性。     

Lower purity dimer acid based polyamides used as hot melt adhesives: synthesis and properties

Hot melt polyamides exhibit high adhesive strength. The polyamides synthesized from dimer fatty acids and diamines can present low crystallinity and a broad range of melting temperatures. In this work, polyamides with different compositions of dimer fatty acids, piperazine, ethylenediamine, sebacic acid and stearic acid and different content of secondary diamine (piperazine) and primary diamine (ethylenediamine) were synthesized. Polyamides with higher purity of dimer acids showed greater molecular weight, adhesion performance and a better mechanical resistance evaluated in stress/strain test. Softening point increased with increase in monomers content. By differential scanning calorimetry analysis, it was observed that polyamides with low percentage of monomer content show only one narrow melting peak in 100 °C. The increase in the acids monomer content leads to a larger temperature range of melting peak. The use of dimer fatty acid with a low content of monomers (up to 6%) in the polyamides synthesis promotes the formation of hot melt adhesives with good adhesion performances. The lowest monomer content leads to an increase in molecular weight, viscosity and mechanical properties of polyamide. Increase in the content of primary amines in polyamides increases crystallinity, viscosity and mechanical properties due to the higher number of hydrogen bonds formed by amide groups.     

Waterborne polyurethane dispersions obtained with polycarbonate of hexanediol intended for use as coatings

Three waterborne polyurethane dispersions derived from polycarbonate of hexanediol (PCD) with molecular weight of 1000 Da were synthesized by the acetone method and used as coatings for stainless steel plates. Different hard segments content in the polyurethanes were obtained by varying the isocyanate/macroglycol (NCO/OH) molar ratio. A decrease in the NCO/OH ratio produced an increase in the mean particle size as well as a decrease in the Brookfield viscosity of the dispersions. Furthermore, the greater the NCO/OH ratio the higher the urea and urethane hard segment content, the higher the glass transition temperature value and the higher the elastic modulus of the polyurethane was. On the other hand, the NCO/OH ratio affected the adhesion of the polyurethanes. The adhesion was evaluated by using three different procedures: T-peel strength tests of flexible PVC/waterborne polyurethane dispersion/flexible PVC joints; single lap-shear tests of aluminium/waterborne polyurethane dispersion/aluminium joints and cross-cutter adhesion test of polyurethane coatings on stainless steel pieces. Finally, several properties of the polyurethane coatings on stainless steel pieces were tested including Persoz hardness, gloss, chemical resistance and yellowness index.     

软段对热塑性聚氨酯弹性体结构及性能的影响

以二苯基甲烷-4,4′-二异氰酸酯(MDI)和扩链剂1,4-丁二醇(BDO)为聚氨酯弹性体硬段(控制硬段质量分数32%),以实验室自制聚己二酸乙二醇酯二醇(PEA)和聚己二酸乙二醇丙二醇酯二醇(PEPA)为软段,经预聚体法合成不同结构的热塑性聚氨酯弹性体(TPU)。研究了弹性体软段部分对其硬度、力学性能和结晶性能的影响。结果表明,控制热塑性聚氨酯弹性体硬段部分不变,改变软段,材料硬度变化不大;软段聚酯二元醇随其相对分子质量的增加,TPU力学性能和结晶性能均增强;研究不同PG含量的软段PEPA-TPU发现,当PG质量分数为10%时,TPU力学性能与结晶性能最好。     

硬段对热塑性聚氨酯弹性体结构及性能的影响

以实验室自制聚己二酸乙二醇酯二醇PEA为软段,二苯基甲烷-4,4’二异氰酸酯(MDI)为硬段,分别采用乙二醇(EG、1,4-丁二醇)、BOD和1,6-己二醇、HG为扩链剂,经预聚体法合成了硬段不同的聚氨酯弹性体。研究了硬段结构和硬段含量对弹性体硬度及力学性能的影响。采用旋转流变仪研究了弹性体在降温条件下的非等温结晶过程。结果表明,当硬段含量相同时,BDO-TPU结晶性能最好,拉伸强度最大;HG-TPU断裂伸长率最好。在BDO-TPU体系中,随硬段含量增加,材料硬度和强度增加,伸长率减小;结晶起始温度逐渐增大,结晶性能增强。     

复合软包装用水性聚氨酯油墨的制备与性能

用不同结构的聚酯二元醇或聚醚二元醇制备水性聚氨酯( WPU)油墨,分别探讨了不同二元醇结构制备的WPU油墨对基材附着牢度、聚己二酸乙二醇-丁二醇酯(PBA)体系的硬段含量对水性油墨抗返粘性、交联剂对水性油墨耐湿性、乙醇溶剂对水性油墨干燥速度的影响.结果表明,用PBA制备的WPU油墨具有较好的附着牢度;硬段质量分数40％...     

PUA共聚乳液及其胶囊的性能研究

采用甲苯二异氰酸酯(TDI)、聚乙二醇(PEG)。丙烯酸为原料,通过分子设计合成了带有双键的PU预聚体。用此预聚体与丙烯酸酯类单体进行共聚,通过测定乳液的粘度、粒径分布、胶膜的机械性能和热性能等方法,讨论了此预聚体用量对乳液和胶膜性能的影响。结果显示：随着预聚体用量的增加,共聚乳液的稳定性、粘度逐渐下降、乳液粒径有较大的变化;PUA共聚乳液胶膜的光泽度、附着力在预聚体用量为4％时最好,其胶膜的抗冲击强度及硬度均好于相应的PA乳液胶膜。     

软段含离子基团的阴离子型水性聚氨酯胶粘剂的研究(Ⅱ)——硬段结构的影响

以含有不同离子基团的聚酯多元醇为软段,采用丙酮法合成了一系列水性聚氨酯乳液。研究了不同硬段结构和硬段含量和扩链剂对其干膜物理机械性能和吸水率的影响。     

含氟二元胺为扩链剂的聚氨酯弹性体的合成和表征

以2,2-双(4-羟基苯基)六氟丙烷(全氟双酚A)为原料合成了2,2-双[4-(4-氨基苯氧基)苯基]六氟丙烷(BAPF6P),以此二元胺为扩链剂制备了一系列不同硬段含量的含氟聚氨酯弹性体(FPUE)。通过FTIR、TG、EA、WAXD、1H-NMR、DMA分析及拉伸试验,对BAPF6P和由其制备的FPUE的结构和性能进行了研究。结果表明,所得产物BAPF6P的结构与预期设计相符;由于FPUE的硬段间的强氢键作用和偶极效应,使得微区中部分链段排列有序形成微晶结构;随着硬段含量的提高,Tg逐渐升高,FPUE的耐寒性能逐渐降低,而耐热氧化性逐渐提高;FPUE的热分解温度在200℃以上,具有良好的耐热性能及优异的力学性能,BAPF6P是一个好的聚氨酯扩链剂。     

Morphology–properties relationship in high‐renewable content polyurethanes

The effect of diisocyanate nature and hard segment content on the morphology and properties of high‐renewable content segmented thermoplastic polyurethanes was studied. Vegetable oil‐based polyether diol and corn sugar derived chain extender were used as renewable reactants together with an aliphatic (1,6‐hexamethylene diisocyanate, HDI) or aromatic (4,4′‐diphenylmethane diisocyanate, MDI) diisocyanate as hard segment. Segmented thermoplastic polyurethanes were synthesized by two‐step bulk polymerization. Morphology and physicochemical, thermal and mechanical properties were analyzed by Fourier‐transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, atomic force microscopy, and mechanical testing. The effect of mechanical deformation over the microstructure was also analyzed. Changes in crystallinity and hard segment hydrogen bonding after mechanical testing were evaluated by Fourier‐transform infrared spectroscopy and differential scanning calorimetry. The increase of physical crosslinking sites by aromatic diisocyanate and chain extender ratio in the polyurethane results in hard segment crystalline domains with spherulitic morphology, which enhance the stiffness and hardness whereas percentage elongation at break diminish. The flexible, linear aliphatic nature of HDI favors the arrangement of urethane groups thus creating strong hard segment interactions and hard segment crystal microdomains composed of fibrillar morphology are observed. POLYM. ENG. SCI., 54:2282–2291, 2014. © 2013 Society of Plastics Engineers