Influence of the hard-to-soft segment ratio on the adhesion of water-borne polyurethane adhesive

Three water-borne polyurethane dispersions were synthesised by the pre-polymer mixing process. Different hard segment contents in the polyurethanes were obtained by varying the diisocyanate/macroglycol (NCO/OH) molar ratio. A decrease in the NCO/OH ratio produced an increase in the mean particle size and in the pre-polymer viscosity, as well as a decrease in the molecular weight of the polyurethane. On the other hand, the lower the NCO/OH ratio, the more crystalline the polyurethane and the lower the resistance to flow at high temperature. Lower NCO/OH ratios improved the thermal degradation stability of the polyurethane. Finally, a high initial adhesion to PVC was obtained in all joints produced with the aqueous polyurethane dispersions and the final adhesion increased as the NCO/OH ratio in the water-borne polyurethane adhesive decreased.     

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。     

水性聚氨酯/聚甲基丙烯酸甲酯杂化乳液的合成

用异佛尔酮二异氰酸酯(IPDI)、聚丙二醇(PPG)和二羟甲丙酸(DMPA)合成了水性聚氨酯分散体(WPU),讨论了PPG摩尔质量,NCO/OH及PPG/DMPA比例对WPU乳液和涂膜性能的影响。以WPU为种子与甲基丙烯酸甲酯进行乳液聚合制备杂化乳液,研究了不同PU/PMMA物质的量比例对杂化乳液及涂膜性能的影响,并采用TEM对WPU及杂化乳液粒子进行了表征。结果表明,在以PPG1000为原料,NCO与OH物质的量比为1.4∶1,PPG与DMPA物质的量比为1∶0.8条件下制备的WPU杂化乳液,随着PMMA比例增加,杂化乳液的稳定性和成膜性变差,聚合物膜断裂伸长率降低,但铅笔硬度、耐水性及耐乙醇性均得到了改善。     

Properties and paper sizing application of waterborne polyurethane emulsions synthesized with isophorone diisocyanate

In this work, a two-step synthesis methodology has been used to synthesize a series of waterborne polyurethane (WPU) emulsions with isophorone diisocyanate (IPDI), poly-caprolactone diol (PCL) and dimethylol propionic acid (DMPA) as monomers and ethylenediamine (EDA) as the chain extender, respectively. The influences of the NCO/OH molar ratio, DMPA content, chemicals-adding sequence, and acetone content on the physical properties of the resultant emulsions have been investigated in detail. The results show that the emulsion viscosity increases with an increase in the NCO/OH molar ratio or DMPA content whereas it declines sharply as the acetone amount increases. The emulsion particle size is seen to increase with the NCO/OH molar ratio but it decreases as the DMPA content increases. The chemicals-adding sequence is observed to strongly affect the particle size and viscosity of the resultant emulsions. For cast films, with an increase in the NCO/OH molar ratio, the elongation monotonically decreases while the tensile strength is seen to increase at first and then deceases. The film water absorption capacity is found to go up as the DMPA content increases. Furthermore, after sized with the emulsions, the paper water resistance is markedly improved and the 30s Cobb value is seen to decrease by 63% as compared to the unsized counterpart. The paper folding resistance and the tensile index are also improved to certain extents. For producing well-performed WPU emulsions for sizing paper sheets, an NCO/OH molar ratio of 1.6–1.8 and a DMPA content of 6.0–7.0 wt.% are preferably chosen.     

环氧树脂改性水性聚氨酯的合成与性能研究

采用环氧树脂（EP）、聚酯二元醇、异佛尔酮二异氰酸酯（IPDI）、二羟甲基丙酸（DMPA）等制备了环氧树脂改性水性聚氨酯。实验选择环氧树脂E-51为改性剂,讨论了EP含量、NCO／OH比值、DMPA含量对体系耐水性、粘接性及力学性能的影响。实验结果表明：EP质量分数为6％～8％、NCO／OH比值为1．3～1．4、DMPA质量分数为6％时,水性聚氨酯样品的性能较好。     

遇水膨胀型聚氨酯的制备与性能研究

以异佛尔酮二异氰酸酯(IPDI)、聚酯二元醇、二羟甲基丙酸(DMPA)、三羟甲基丙(烷TMP)等为原料,合成了遇水膨胀型聚氨酯。用FTIR对该聚氨酯进行了结构表征,并对其遇水体积膨胀率和力学性能进行了研究。结果表明:NCO/OH摩尔比(异氰酸酯指数)为1.3～1.4时试样遇水体积膨胀率较高;随着DMPA用量的增加,试样的遇水体积膨胀率增大,拉伸强度保持率降低;加入TMP后,聚氨酯形成化学交联,拉伸强度保持率得到改善但,是试样的体积膨胀率随着TMP用量的增加而降低。     

阴离子型水性聚氨酯胶粘剂的合成研究

文章以二异氰酸醣、聚醚二元醇、二羟甲基丙酸（DMPA）等为基本原料制备了一种稳定的聚醚型阴离子水性聚氨酯胶粘剂,分析了水性聚氨酯胶粘剂的制备条件、催化剂用量、增稠剂等因素对水性聚氨酯胶粘剂乳液、胶膜及剥离强度的影响。     

层压复合用PBA-IPDI型水性聚氨酯胶粘剂的制备

以聚己二酸-1，4-丁二醇酯二醇(PBA)、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DM-PA)等为原料，采用内乳化法合成了阴离子型水性聚氨酯胶粘剂。研究：NCO／OH摩尔比、封端剂用量、PBA相对分子质量、存放时间以及助溶剂用量对胶粘剂性能的影响。     

高固含量水性聚氨酯分散体的合成

引　言水性聚氨酯是水溶型、水分散型和水乳化型聚氨酯的统称 .水性聚氨酯与溶剂型相比较 ,具有生产、运输和使用安全 ,不污染环境的优点 ,在涂料、黏合剂和皮革涂饰剂等方面的应用备受重视[1] ,成为近 10年来全世界的研究热点 .水性聚氨酯的弱点是其制成的涂料和涂饰剂的机械性能、耐水性不如溶剂型聚氨酯 .克服这些弱点 ,是近年来各国研究者努力的方向[2 ] .在改善水性聚氨酯性能方面有大量研究报道 ,诸如降低亲水基团含量 ,增大乳液粒径 ,采用强力机械分散增加乳液贮存稳定性 ,改善乳液对涂膜基材表面的润湿性、黏附力等等[3] .但很少见…     

硅烷偶联剂改性高固含量水性聚氨酯的合成

以聚四氢呋喃二醇、聚己二酸乙二酯和异佛尔酮二异氰酸酯等为主要原料,以硅烷偶联剂KH550为改性剂,2,2-二羟甲基丙酸(DMPA)和(1,3-二氨基)-丁基磺酸钠(HSJ)为亲水扩链剂,采用自乳化和外乳化相结合的方法合成阴离子型高固含量硅烷偶联剂改性水性聚氨酯(WPU)乳液。考察了乳化剂、扩链剂、硅烷偶联剂用量,异氰酸酯基与羟基摩尔比(R值)等对乳液和胶膜性能的影响。通过傅里叶变换红外光谱、热重分析和接触角测试分析了改性前后WPU的结构。结果表明:DMPA,HSJ,乳化剂,硅烷偶联剂的质量分别占总固体质量的1.60%,0.26%,1.60%,1.50%,R值为1.20时,可得到固含量54%、黏度低、稳定性好、耐水、耐热性能优异的WPU乳液。     

稳定水性聚氨酯分散液的合成研究

以聚酯、聚醚混合低聚物二醇为原料 ,采用二级扩链技术[1] 合成了阴离子分散液 ,并研究了聚酯二醇/聚醚二醇、NCO/OH等因素对其性能的影响 ;当原料为 PBA/PEG=(1～ 4)∶ 1 ,NCO/OH=(1 .5～ 1 .8)∶ 1时能够得到黏度、硬度、柔韧性、吸水率、拉伸强度、断裂伸长率、分散性、机械稳定性等综合性能优良的分散液。     

聚酯型水性聚氨酯的合成和性能研究

以甲苯二异氰酸酯(TDI)、聚酯二元醇、二羟甲基丙酸等为主要原料合成了聚酯型水性聚氨酯乳液。研究了三羟甲基丙烷(TMP),二羟甲基丙酸(DMPA),异氰酸酯基与羟基物质的量比(n/n)等对水性聚氨酯耐水性能、稳定性以及力学性能等的影响。结果表明,当n/n为NCO OH NCO OH2,DMPA含量为6%,TMP加入量0.6%,水性聚氨酯性能最佳。     

羧酸型水性聚氨酯分散液的制备与性能研究

以聚己二酸丁二醇酯二醇(PBA3000)、异佛尔酮二异氰酸酯(IPDI)和2,2-二羟甲基丙酸(DMPA)为主要原料,合成了羧酸型水性聚氨酯(WPU)。结果表明:一步法和两步法制成的WPU分散液及其胶膜特性相近,但一步法制备工艺更加简单;随着DMPA含量不断增加,预聚过程中体系黏度和分散液电导率上升,WPU胶膜的拉伸强度、硬度和吸水率增大,断裂伸长率和分散液粒径(100 nm)减小;当n(PBA)∶n(DMPA)=2∶3时,R值越大,预聚过程中体系黏度越低,WPU胶膜的拉伸强度和硬度越大,而断裂伸长率和吸水率越小;当w(-COOH)=1.09%～2.37%时,WPU分散液的稳定性较好。     

Effect of the NCO/OH ratio on the properties of Mesua Ferrea L. seed oil‐modified polyurethane resins

A series of polyurethane resins with varying NCO/OH ratios (0.8–2.0) has been synthesized from the monoglyceride of Mesua Ferrea L. seed oil, poly(ethylene glycol) (M_n, 200 g mol^?1) and 2,4‐toluene diisocyanate in the presence of dibutyl tin dilaurate as the catalyst. The effects of the NCO/OH ratios of the synthesized resins on the physical properties, such as hydroxy values, acid values, saponification values, iodine values, specific gravities and isocyanate values have been studied. The formation of the polyurethane resins was confirmed by viscosity measurements, and FTIR, UV and ¹H NMR spectroscopic studies. Performance characteristics, such as impact resistance, flexibility, gloss, hardness, adhesive strength and chemical resistance, of the cured resins were investigated as a function of the varying NCO/OH ratios, with an influence of these ratios being observed for most of the above properties. Thermogravimetric analysis (TGA) demonstrated that the thermal stabilities of the cured resins increased with an increase in the NCO/OH ratios. The amounts of char residues at 550 °C were also found to be greater for higher NCO/OH ratios of the oil‐modified polyurethane resins. Copyright © 2005 Society of Chemical Industry     

羟乙基封端聚二甲基硅氧烷改性水性聚氨酯的合成

以聚四氢呋喃二醇、异佛尔酮二异氰酸酯（IPDI）和2,2-二羟甲基丙酸（DMPA）为主要原料,羟乙基封端聚二甲基硅氧烷（SHG）为改性剂,采用自乳化法合成了阴离子型有机硅改性水性聚氨酯（WPU）。考察了异氰酸酯基与羟基的量之比（R值）、DMPA用量及SHG用量对WPU及其胶膜性能的影响;通过荧光显微镜分析了改性前后WPU的结构。结果表明：当异氰酸酯基与羟基的量之比为1.2、DMPA质量分数为4%、SHG质量分数为2%时,改性WPU的黏度低、稳定性好;其胶膜的吸水率从17%下降至6%,接触角从30.3°提高至75.7°,耐热性提高;微观形态更规整。     

聚酯-聚醚混合型水性聚氨酯的合成工艺研究

以聚己二酸丁二醇酯二醇（PBAG）和聚乙二醇（PEG）为软链段,以异佛尔酮二异氰酸酯（IPDI）和二羟甲基丙酸（DMPA）为硬链段,采用预聚体法制备了水性聚氨酯（WPU）,研究了R值（NCO／OH摩尔比）、DMPA用量、聚酯与聚醚摩尔比等对乳液的粘度、粒径、稳定性和聚氨酯胶膜力学性能的影响。结果表明,选用尺值为2．0、DMPA质量分数为3．5％、聚酯与聚醚摩尔比为2．5,制备的聚酯-聚醚混合型WPU的粒径可以达到310nm,粘度达到65mPa·s,其离心稳定性和wPU膜力学性能良好。经WPU涂层整理织物的耐静水压达到6．08kPa,透湿量达4550g／（m2×24h）,符合服用性能的要求。     

HDI型水性聚氨酯胶粘剂的制备与性能研究

以聚酯二元醇、二异氰酸酯(HDI)与2,2-二羟甲基丙酸(DMPA)为主要原料,采用丙酮法合成了HDI型水性聚氨酯(WPU),探讨了亲水扩链剂DMPA用量对WPU乳液粒径、耐水性、耐热性及剥离强度等性能的影响。结果表明:随着DMPA含量不断增加,WPU乳液粒径减小,WPU膜的吸水强度、耐热性和剥离强度先升高后降低。当R(NCO/OH)值为2.226,扩链剂DMPA的加入量为3.5~4%时,可获得综合性能较好的水性聚氨酯。     

水性聚氨酯电导率与聚沉值的研究

研究了软（硬）段含羧基的水性阴离子纳米聚氨酯体系的n(NCO)/n(OH)比值，COOH的质量分类，反离子各类，合成方法与电导率关系及产生的原因；探讨了该体系的n(NCO)/n(OH)值，COOH的质量分数，合成方法与临界聚沉值（Cc.c)的关系和规律。并分析，比较了软（硬）段含羧基的水性阴离子聚氨酯体系电导率与Cc.c二者关系，得出了随COOH的质量分数升高，二者变化相同，随n(NCO)/n(OH)比值升高,二者变化相反的结论。     

AAS/DMPA对水性聚氨酯胶膜结晶性能的影响

以聚己二酸1,4-丁二醇酯(PBA)、六亚甲基二异氰酸酯(HDI)、异佛尔酮二异氰酸酯(IPDI)为主要原料,以混合的乙二胺基乙磺酸钠(AAS)和二羟甲基丙酸(DMPA)为亲水性扩链剂,通过丙酮法合成了固含量为50%的磺酸/羧酸盐型水性聚氨酯(WPU)乳液。采用DSC、XRD、透光率等测试技术表征了AAS/DMPA摩尔比对WPU胶膜结晶性的影响,并从吸水率和热失重两个方面分析了结晶性对胶膜耐水性和耐热性的影响。研究结果表明,随着AAS/DMPA摩尔比的增大,WPU胶膜的结晶性提高,胶膜的耐水性和耐热性在一定程度上得到了改善。     

水性聚氨酯皮革涂饰剂的合成

以聚四氢呋喃醚和异佛尔酮二异氰酸酯为原料,在预聚反应中引入二羟甲基丙酸亲水扩链荆,以三乙胺为中和剂,采用内乳化法合成了阴离子型水性聚氨酯皮革涂饰剂。研究了NCO/OH摩尔比、DMPA引入量、乙二胺用量、封端荆正丁醇用量和存放时间对涂饰剂及膜性能的影响。