水性聚氨酯预聚反应影响因素浅探

以TDI、N210、DMPA为基本原料，用丙酮法合成了稳定的聚氨酯乳液（WPU）。探讨了反应温度、溶剂、催化剂及用量等影响因素对预聚反应的影响。结果表明，以丙酮为溶剂，以二月桂酸二丁基锡为催化剂、反应温度80℃最为适宜。     

反应条件对水性聚氨酯预聚反应的影响

以TDI、N210、DMPA为基本原料,用丙酮法合成了稳定的聚氨酯乳液（WPU）。探讨了反应温度、溶剂、催化剂及用量对预聚反应的影响。结果表明：以丙酮为溶剂,以二月桂酸二丁基锡为催化剂（用量0．03％）,反应温度80℃最为适宜。     

影响水性聚氨酯预聚反应的因素

以TDI、N210、DMPA为基本原料，用丙酮法合成了稳定的聚氨酯乳液(WPU)。研究了反应温度、溶剂、催化剂及用量对预聚反应的影响。结果表明：以丙酮为溶剂，以二月桂酸二丁基锡为催化剂(用量0．03％)，反应温度80℃它最为合适。     

影响TDI-TMP预聚物贮存稳定性的因素

讨论了甲苯二异氰酸酯－三羟甲基丙烷（TDI－TMP）预聚物的固体分、投料比、反应温度和溶剂等因素对预聚物对贮存稳定性的影响，确定了制备贮存稳定性好的TDI－TMP预聚物的工艺条件。     

一种新型光固化聚氨酯乳液的合成研究

采用丙酮法的合成工艺,以2,4-甲苯二异氰酸酯（TDI）、聚己二酸丁二醇酯（PBAl000）、二羟甲基丙酸（DMPA）、自制的三羟基中间体为主要原料,制备了一种新型光固化聚氨酯乳液。实验表明：当DMPA用量为6％～8％,三羟基中间体用量为5％时,所得乳液的综合性能良好,50℃恒温贮存30d不分层、无沉底。固化后漆膜硬度2H,耐丁酮擦拭性100次以上不透底。     

水性聚氨酯的合成与改性

以甲苯二异氰酸酯(TDI)、聚醚二元醇(N220)和二羟甲基丙酸(DMPA)为主要原料,采用三羟甲基丙烷(TMP)进行交联改性合成了水性聚氨酯(WPU),研究了n(-NCO)/n(-OH)、DMPA及TMP对WPU的耐水性、稳定性和力学性能的影响。研究发现,改性后的乳液常温贮存稳定性好,适度交联可提高胶膜的拉伸强度及耐水性。     

有机硅改性水性聚氨酯乳液的制备及其性能研究

以甲苯二异氰酸酯(TDI)、聚醚二元醇(N-220)、1,4-丁二醇(BDO)、二羟甲基丙酸(DMPA)和硅烷偶联剂(KH-550)等为主要原料,采用丙酮法合成了有机硅改性WPU(水性聚氨酯)乳液。结果表明:KH-550和DMPA的加料方式对WPU乳液稳定性影响较大;当w(DMPA)=3%～5%时,WPU乳液及其胶膜的综合性能较好。     

双羟基染料改性有色水性聚氨酯的制备与性能

为了探究双羟基染料不同引入方式对水性聚氨酯（WPU）乳液及其成膜性能的影响,采用异佛尔酮二异氰酸酯、聚四氢呋喃（PTMG）、2,2-二羟甲基丙酸和1,4-丁二醇（BDO）合成了WPU乳液。将酸性红87作为扩链剂部分替代BDO制备了有色化学共聚聚氨酯（ARWPUA-1～3）乳液;将酸性红87作为软段部分替代PTMG制备了有色化学共聚聚氨酯（ARWPUB-1～3）乳液;将酸性红87与WPU共混制备了WPU/AR。采用FTIR、1HNMR和UV-Vis对样品的结构进行了表征;考察了不同有色WPU的贮存稳定性、耐溶剂性、颜色特征值、耐干/湿摩擦色牢度以及力学性能,并对其进行了分子动力学模拟。结果表明,由n(酸性红87)∶n(BDO)=1∶4制备的ARWPUA-2具有优异的贮存稳定性;在不同溶剂中均不会发生溶解脱色现象;具有良好的耐干/湿摩擦色牢度和较高的力学性能,其拉伸强度22.6 MPa,断裂伸长率为810%。     

PVC板门用单组份湿固化聚氨酯胶黏剂的研制

采用组合异氰酸酯和组合聚醚多元醇合成可室温固化的单组分聚氨酯胶黏剂。考察NCO／OH的物质的量比对贮存稳定性、反应时间、剥离强度的影响,并论述了引入TDI的作用以及组合溶剂的确定。通过优化配方,合成了用于粘接PVC板材和松木材的新型胶黏剂,并获得良好的粘接强度。结果表明：反应时间随着NCO／OH物质的量比的增大而增加;NCO／OH物质的量比低时,胶的贮存稳定性变差,当比值高时,胶的贮存稳定性好;NCO含量在9％时,胶的剥离强度最高;PAPI：TDI=7：3时,胶的剥离强度达到3．25N／mm。组合溶剂二氯甲烷：丙酮=5：1时,胶的剥离强度达到3．20N／mm。     

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...     

木材加工用水性聚氨酯胶粘剂的研究

为了获得稳定性较好的水性聚氨酯(WPU)胶粘剂,以丙酮为溶剂、聚醚(N210)为软段、二苯基甲烷-4,4′-二异氰酸酯(MDI)为硬段、二羟甲基丙酸(DMPA)为亲水性扩链剂、三乙胺(TEA)为成盐剂和聚乙烯醇(PVA)为增稠剂等,制备了环保型木材粘接用WPU胶粘剂。研究了MDI、N210、DMPA、TEA和PVA用量等对乳液稳定性、胶粘剂剪切强度及黏度的影响。结果表明:当n(MDI)∶n(N210)∶n(DMPA)∶n(TEA)=2.4∶1∶0.8∶0.64、w(PVA)=2.0%～3.0%时,可制得常温(20～30℃)存放90 d以上、剪切强度超过4.2 MPa的稳定WPU胶粘剂。     

聚碳酸酯二醇型水性聚氨酯胶粘剂的研究

采用预聚体分散法制备了一系列聚碳酸酯二醇(PCDL)型水性聚氨酯(WPU)胶粘剂,并借助傅里叶变换红外光谱(FT-IR)法来跟踪预聚体的合成过程,同时还考察了该WPU胶粘剂的粘度、热稳定性和初粘强度等性能。实验结果表明,PCDL的结构和相对分子质量对该WPU胶粘剂的性能影响很大;以PCDLT-6002为原料制备的WPU胶粘剂,其粘度最低(175 mPa.s)、热稳定性最好、软链段玻璃化转变温度(Tg)最低(-33.97℃)、有软段结晶熔融峰且初粘强度最高(81N/25 mm,此时活化温度为70℃)。     

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。     

Influence of preparation method on adhesion and drying performances of polyurethane dispersion

Waterborne polyurethane (WPU) dispersions with a high solid content were prepared by one-step and two-step methods with polyester and polyether type macromolecular diols as the main raw materials. The effects of two synthesis methods on the properties of WPU of polyester and polyether were studied. Fourier transform infrared spectroscopy, particle size and distribution, and Thermogravimetric analysis (TGA) measurements were utilized to characterize the structure. The dryness test results showed that the WPU synthesized with polyester diol as the soft segment by the two-step method had the best drying. In addition, the microstructure of WPU was characterized by transmission electron microscopy, which confirmed that WPU was mainly spherical structure. TGA and scanning electron microscopy results showed that the microphase separation between the soft and hard segments of WPU prepared by the two-step method was weaker, the hydrogen bonding was stronger, the adhesion, and thermal stability of WPU was improved.     

Preparation of waterborne polyurethane adhesives based on macromolecular-diols containing different diisocyanate

ABSTRACT

Three different macromolecular diols were synthesized by the reaction of Poly(1,4-butanediol adipate) diol (PBA) and diisocyanate (Isophorone diisocyanate (IPDI), Hexamethylene diisocyanate (HDI) and Methylene-bis(4-cyclohexylisocyanate)(HMDI)) at the ratio of 2:1. Based on these macromolecular diols, waterborne polyurethane (WPU) adhesives were prepared. The structure and molecular weights of the WPU were characterized by Nuclear magnetic resonance spectroscopy (¹H NMR), Fourier Transform Infrared Spectroscopy (FTIR) and Gel permeation chromatography (GPC) respectively. Furthermore, the hydrogen bonding interaction of WPU were analyzed by the deconvolution FTIR spectra. The results showed that the hydrogen bonded NH was increased when carbamate was in the soft segment. The crystallinity of WPU was tested by X-ray diffraction (XRD) and Differential scanning calorimetry (DSC). The results showed that the crystallinity of WPU2 (HDI) and WPU3 (HMDI) were enhanced, especially for WPU2. Meanwhile, the Tg,s as well as the mechanical strength, storage modulus, the contact angle and thermo-stability were increased with the introduced carbamate into soft segment. The T-peel tests of plasticized PVC/WPU/plasticized PVC joints and lap-shear tests of wood/WPU adhesive/wood joints were carried out. The results indicated that the carbamate in the soft segment could significantly enhance the adhesion of WPU at an appropriate activation temperature.     

Preparation and characterization of waterborne polyurethane containing PET waste/PPG as soft segment

Soft drinks poly(ethylene terephthalate) (PET) bottles were depolymerized by glycolysis using a 1 : 3 molar ratio of PET repeating unit to glycols like neopentyl glycol (NPG) and dipropylene glycol (DPG). Further, a series of waterborne polyurethanes (WPUs) was synthesized using pure polypropylene glycol (PPG), and glycolyzed oligoesters/PPG blends in different molar ratios as soft segment. Thermal property of WPU was tested by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Moreover, viscosity and particle size of WPU were also investigated. The results show that introduction of a certain amount of glycolyzed oligoester to soft segment makes the degree of hard‐soft domain microphase separation smaller, and can also improve thermal stability of WPU. Furthermore, WPUs synthesised from glycolyzed oligoesters and PPG blends possess larger particle size, better particle size distribution, relative lower and more stable viscosity. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42757.     

Structural characterization and mass transfer properties of polyurethane block copolymer: influence of mixed soft segment block and crystal melting temperature

An attempt has been made to investigate the influence of mixed soft segment on structure and mass transfer properties of segmented polyurethane (SPU). For this purpose polyurethane block copolymer containing soft segment such as polycaprolactone glycol (number‐average molecular weight 3000, PCL 3000), PCL 3000–polypropylene glycol (number‐average molecular weight 3000, PPG 3000), PCL 3000–polytetramethylene glycol (number‐average molecular weight 2900, PTMG 2900), PPG 3000–PTMG 2900, were synthesized using a two‐step or three‐step synthesis process. All the SPUs were modified with the hydrophilic segment, i.e. diol‐terminated poly(ethylene oxide) (number‐average molecular weight 3400, PEG 3400). Fourier‐transform infrared, wide‐angle X‐ray diffraction, differential scanning calorimetry, and dynamic mechanical thermal analysis were used to characterize the polyurethanes. The mass transfer properties were measured by equilibrium sorption and water vapor permeability measurements. Mixed blocks loosen the inter‐chain interaction due to phase mixing which decreases the crystallization of the soft segment in the resulting SPU. The crystallinity of mixed polyol block SPU increases when both polyols are crystallizable in the pure state. Highest loss tan δ value was observed for the sample containing PTMG 2900–PPG 3000 mixed soft segment due to their flexible and phase mixed structure which increases the chain mobility; this sample performed best among all four SPUs in equilibrium water sorption as well as water vapor permeability owing to their loose and nearly amorphous structure. Soft segment crystal melting further enhances the water vapor permeability significantly, which would make the membrane suitable for breathable textiles, packaging and medical applications. Copyright © 2006 Society of Chemical Industry     

Effects of a soft segment component on the physical properties of synthesized waterborne polyurethanes by using triblock ester-ether copolydiol as the soft segment

This paper examines the effect of an ester-ether soft segment structure on the physical properties of synthesized WBPUs. The CET series, CPT series, and CMT series anionic waterborne polyurethane (WBPU) were prepared with PCL-PEG-PCL, PCL-PPG-PCL, and PCL-PTMG-PCL triblock copolydiol as the soft segment. These copolydiols were synthesized from polyethylene glycol (PEG), polypropylene glycol (PPG), or polytetramethylene glycol (PTMG), respectively, by end capping with caprolactone (CL). Particle size and its distribution, solvent absorption, thermal properties, and the mechanical properties of the WBPUs were studied. The particle size of WBPU dispersion was in the sequence of CET > CPT > CMT series. The CET series WBPU had better phase mixing between the soft and hard segment, whereas the CMT series WBPU had good phase separation and better mechanical properties. In addition, both the phase mixing and mechanical properties increased with PCL content, except for the CMT series WBPU.     

Polarity measurements in block copolymers (polyurethaneimides) and correlation with their pervaporation features

EtOH/ETBE azeotropic mixture was separated by pervaporation through films of polyurethaneimides (PUI), i. e., alternating block copolymers varying in their structure only by their oligomeric soft blocks. Pervaporation performances strongly depend on the flexible segments: fluxes on the molecular weight and selectivity towards ethanol on the chemical structure in the decreasing order: PEG, PCL, PCD, PTMG, PPG. In order to correlate selectivity with segment polarity, a new solvatochromic polarity probe that was well soluble in PUI was synthesized. Using 13 solvents covering a wide polarity range, Vis λ^max of the photochromic indicator open form was linearly correlated with the E_T(30) polarity scale. By illumination of the dissolved dye, PUI polarity was investigated in relation to soft segment nature and size. The very high PUI polarity values and their splitting for highest size segments were assigned to preferential probe solvation by interblock urethane junctions combined with phase segregation. Polarity values consistent with the chemical structure of the flexible segments were provided by similar measurements on suitably end-capped precursors of these segments and were then linearly correlated with the related PUI pervaporation selectivity. © 1995 John Wiley & Sons, Inc.