Synthesis and properties of crosslinked waterborne polyurethane

Waterborne polyurethane prepolymer was prepared by the reaction of isophorone isocyanate(IPDI), polyether polyol(PTMG), dimethylol propionic acid(DMPA) and trimethylol propane(TMP), which was modified by silicane coupling agent(APTES) to form highly crosslinked polyurethane emulsion. The films of the waterborne polyurethane were prepared. The structure of the polyurethane was characterized by Fourier transform infared spectrometer (FTIR), X-ray diffraction (XRD) and differential scanning calorimeter (DSC). The mechanical properties and water absorption of the films were measured. FT-IR indicates that APTES reacted with -NCO of polyurethane. XRD and DSC shows that crystallinity of polyurethane decreased with the increase of w(APTES). Tensile strength increases as the NCO/OH ratio increases. Tensile strength of films increases with increase of w(DMPA) and elongation at break decreases. The water absorption decreases with the increase of w(TMP) when w(TMP) is lower than 1.8%. As the mass fraction of APTES increases from 0% to 10%, the tensile strength of PU films increased from 18 MPa to 28 MPa, water absorption and ethanol absorption decreased.     

Preparation and properties of waterborne cationic fluorinated polyurethane

Waterborne cationic fluorinated polyurethane (WCFPU) micro-emulsion was prepared by the reaction of isophorone diisocyanate (IPDI), polytetramethyleneether glycol (PTMG1000), 1,4-butanediol (BDO), N-methyldiethanolamine (MDEA), trimethylolpropane (TMP) and perfluoroalkylethyl octanol (FEOH), and then the films of the WCFPU were prepared. The influence on the mechanical properties and water absorption of the films, such as the molar ratio of NCO to OH, the dosage of MDEA, TMP and FEOH, was investigated. Their structure, morphology and heat performance were characterized by fourier transform infared spectrometer (FT-IR), dynamic light scattering (DLS), transmission electron microscope (TEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and thermogravimetry (TG). The results revealed that the best mechanical properties and water resistance could be obtained under the condition that NCO/OH molar ratio was 1.25, w(TMP) was 1.1%, w(MDEA) was 7.29% and w(FEOH) was 22.3%. In addition, WCFPU was endowed with low surface energy of its film and the membrane surfaces had excellent water and oil repellency. Furthermore, the thermal stability of the waterborne cationic fluorinated polyurethane increased with the incorporation of perfluoroalkyl chain. And XRD, DSC and TG showed that micro-crystallinity of polyurethane increased with the increase of FEOH, which was benefit to the micro-phase seperation.     

Waterborne polyurethane-silica nanocomposite adhesives based on castor oil-recycled polyols: Effects of (3-aminopropyl)triethoxysilane (APTES) content on properties

Waterborne castor oil-recycled polyol based polyurethane-silica nanocomposite adhesives (WPU) with polymer matrix and silica nanoparticles chemically bonded have been successfully prepared through a sol-gel process. A series of waterborne polyurethane adhesives with hard segment contents from 71.3 to 74.5 wt%, were synthesized using an isophorone diisocyanate, 2-bis(hydroxymethyl) propionic acid, recycled castor oil-based as soft segments and (3-aminopropyl)triethoxysilane (APTES) as chain extender. The depolymerized oligoester obtained from glycolysis of poly(ethylene terephthalate) (PET) waste using triethylene glycol (TEG), was transesterified with castor oil (CO) which resulted in the formation of hydroxyl-functional polyester polyol, with hydroxyl value of 414 mgKOH g⁻¹. The molecular structures and mass of glycolyzed PET oligoesters, castor oil-based polyol and castor oil-based polyurethane-silica nanocomposite adhesives were estimated by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The structure and properties of the resulting films were investigated by FTIR, wide angle X-ray diffraction measurement (XRD), thermogravimetry (TG) and differential scanning calorimetry (DSC). TG analysis indicated that APTES can improve the thermal stability of WPU. XRD showed that the crystallinity of WPU decreased with the increase alkoxysilane content. The extent of crosslinking was investigated to show a dependence on silica concentration, which increased the glass transition temperature and particle size of polyurethane nanocomposites with increasing alkoxysilane content due to the condensation of the alkoxysilane groups. The hardness, adhesion and gloss quality of the polyurethane films were also determined considering the effect of APTES content, so this paper confirmed the suitability of using these castor oil-based waterborne polyurethane-silica nanocomposites as new adhesive materials with high performance coatings materials. The experimental results reveal that the APTES and the hard segment content play a key role in controlling the structure and properties of the PU cast films based on castor oil-recycled polyols.     

Effect of nanosilica content on properties of polyurethane/silica hybrid emulsion and its films

Polyurethane/silica hybrid emulsion (PUSi) was synthesized by the reaction of isophorone isocyanate, polyether polyol, hydrophilic nanosilica (A200), dimethylol propionic acid, trimethylol propane, and 3‐aminopropyltriethoxysilane (KH550). The films of the waterborne polyurethane (WPU) were prepared. The structure of the polyurethane was characterized by Fourier transform infrared spectrometer (FTIR), thermogravimetry (TG), and differential scanning calorimetry (DSC). The particle size distribution and morphology of emulsion were examined. Influence of nanosilica content on the mechanical properties and solvent absorption of the cast films were also measured quantificationally. FTIR indicates that  NH₂ of KH550 reacted with  NCO of polyurethane. TG analysis indicates that nanosilica can improve thermal stability of polyurethane. There is no clear effect of nanosilica on the glass transition of soft segments. It was found that greater mechanical properties of WPU were obtained when chemical networks were formed by sol‐gel process. As the nanosilica content increases, water absorption and ethanol absorption decreased. The particle size increases with increase of A200 content. PUSi hybrid emulsions are endowed with pseudoplasticity. The apparent viscosity of emulsions increased and then decreased with addition of A200. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and Performance of Waterborne Polyurethane/Nanosilica Hybrid Materials

The polyurethane prepolymer was synthesized, and hydrophilic nano-sized silica (A200) was added to the prepolymer with KH550 as a coupling agent, then a waterborne polyurethane/nanosilica hybrid material (WPUNS) was obtained by a sol-gel process. The structure and performance of the WPUNS films were studied by FTIR, TG, DSC and physical mechanical testing. The particle size and distribution of WPUNS hybrid emulsion was analyzed by a dynamic light scatter (DLS). The morphology of emulsion and films were observed by Transmission Electron Microscope (TEM) and Atomic Force Microscope (AFM), respectively. FTIR analysis indicates the formation of chemical bond between WPU and A200. TEM images display that A200 particles were encapsulated by PU macromolecules and formed a composite particles structure. As the mass fraction of A200 increased from 0 to 2%, the particle size increased from 79.9 nm to 139.9 nm, the tensile strength of the films increased from 6.32 MPa to 20.46 MPa, water absorption decreased from 28.3% to 6.3%, and the hardness was also improved. The TG result indicates that A200 can improve thermal stability of WPUNS. DSC shows that there is no clear effect of nanosilica on the glass transition of soft segments. AFM displays that the smoothness of the films increases with A200 addition.     

Effects of polydimethylsiloxane concentration on properties of polyurethane/polydimethylsiloxane hybrid dispersions

A series of waterborne polyurethane (WPU) derived from isophorone isocyanate and poly(tetramethylene glycol) were modified by hydroxyl‐terminated polydimethylsiloxane (HPMS). The solutions were then cast into films named as PUHS. Rheological behavior of the emulsions were studied using Rheometer and morphology was studied with transmission electron microscope. Meanwhile, the casting films were prepared from the WPU/HPMS hybrid dispersions, and their glass transition behavior, miscibility, water resistance, and medium resistance were studied with differential scanning calorimeter (DSC), wide‐angle X‐ray diffraction (WAXD), and so on. The results revealed that the emulsions' particle size decreases with increasing HPMS content and the particles are more easily affixed to each other when the HPMS content is more than 15%, and emulsions are endowed with pseudoplasticity and thixotropy. WAXD and DSC figures manifested that the casting films all exhibited a certain degree of miscibility. The degrees of crystallinity (x_c) decreased with increasing HPMS content, and the PUHS films were almost amorphous. It is noticed that water and medium absorption increased in the HPMS/PU compared to pure PU, which demonstrate that the membrane surfaces have excellent water and chemical medium repellency. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5538–5544, 2006     

Modified cellulose nanocrystals enhancement to mechanical properties and water resistance of vegetable oil-based waterborne polyurethane

Environmentally friendly and lightweight silylated cellulose nanocrystal (SCNCs)/waterborne polyurethane (WPU) composite films that exhibit excellent mechanical properties and water resistance were prepared. The cellulose nanocrystals (CNCs) of the filamentous structure were surface-modified by γ-aminopropyltriethoxysilane (APTES) and then introduced into a castor oil-based aqueous polyurethane (WPU) matrix by in situ polymerization. The morphology and silylation degree of CNCs were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier infrared transform spectroscopy at different APTES concentrations. The results showed that the surface of the nanocellulose crystal has the best silylation morphology and thermal stability with incorporation of 6 wt % APTES. The thermal stability, mechanical properties, surface morphology, and water resistance of the nanocomposites were investigated by TGA, tensile test, SEM and optical contact angle, water absorption test, and mechanical property test after immersed in water. It was found that the effective introduction of modified CNCs resulted in a significant increase in tensile strength at high levels, and the thermal stability and hydrophobicity of the material were improved simultaneously, reaching the percolation threshold at a 0.50 wt % SCNCs as determined theoretically. This study provided an approach to the design and development of surface-modified CNCs/vegetable oil-based polymer composites by using an appropriate concentration of silane coupling agent to modify CNCs and improve the compatibility between nanocellulose and vegetable oil-based polymer matrices. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48228.     

HDI/IPDI对水性聚氨酯及胶膜性能的影响

采用预聚体分散法制备了一系列固含量为50%的水性聚氨酯(WPU),并通过傅里叶红外光谱(FT-IR)、粒径分析仪、X射线衍射(XRD)、差示扫描量热分析(DSC)、拉力试验机等仪器进行表征,研究了HDI/IPDI摩尔比对WPU的乳液性能和胶膜结晶性能、力学性能、耐水性能,以及基材EVA/PVC粘接性能的影响,分析了不同摩尔比的HDI/IPDI和粘接时间与WPU胶黏剂对EVA/PVC粘接性能的关系。研究发现,随着HDI/IPDI摩尔比增加,水性聚氨酯的乳液性能、软硬段的结晶性都得到提高,而胶膜拉伸强度呈先增大后减小的趋势,断裂伸长率则先减小后增大。所有WPU胶膜都有很好耐水性,胶膜吸水率都在5.0%（质量）以下。粘接实验结果表明,WPU胶黏剂对EVA/PVC具有优异的粘接性能,24 h后可对基材产生界面破坏,随着HDI/IPDI摩尔比增加,胶黏剂的粘接强度增大。当HDI/IPDI=7∶1时,水性聚氨酯的综合性能最好。     

碳点/水性聚氨酯复合材料的制备及性能

以异氟尔酮二异氰酸酯(IPDI)和聚氧化丙烯二醇(PPG)为原料制备水性聚氨酯,以此为碳源,采用水热法制备碳点,再以IPDI和聚己二酸-1,4-丁二醇酯二醇(PBA)为原料,将不同质量分数的碳点加入反应体系中,制得碳点/水性聚氨酯复合材料。采用FTIR、TEM、SEM、TGA、DSC、UV-Vis、荧光光谱以及力学性能测试等对复合材料结构和性能进行检测和表征。结果显示,复合胶膜的热稳定性、荧光性能、力学强度都因碳点的加入得到提高,当碳点加入质量分数达0.5%时,复合胶膜的量子产率和荧光寿命分别为4.15%和2.43 ns,胶膜的拉伸强度和断裂伸长率分别为36.80 MPa和660%,比未加碳点的样品分别提高了29.7%和33.3%。     

Study on the preparation of PU/HBP‐NH2 blend film and its properties

The blend films of polyurethane (PU) and amino‐terminal hyperbranched polymers (HBP‐NH₂) were prepared successfully by mixing HBP‐NH₂ solution and PU. The rate of moisture absorption and mechanical properties were determined. The results showed that the rates of moisture absorption and vapor permeability were improved from 0.34% to 7.51% and from 161 gm^?2 d^?1 to 879 gm^?2 d^?1, respectively. The addition of HBP‐NH₂ is helpful to improve the hygiene properties of PU films. Then, the structures of the blend films were characterized by IR, XRD, TG, and SEM at the same time. The results indicated that HBP‐NH₂ and PU had hydrogen‐bond interaction and a certain phase separation. The blend films had good heat stability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41383.     

甲基丙烯酸羟乙酯改性水性聚氨酯的合成与应用

以甲苯二异氰酸酯(TDI)和聚乙二醇(PEG)为原料,选用2,2-二羟甲基丁酸(DMBA)为扩链剂合成水性聚氨酯(WPU),通过甲基丙烯酸羟乙酯(HEMA)对水性聚氨酯进行封端,采用自乳化法,制备了HEMA改性水性聚氨酯乳液(HEMA-WPU)。通过红外、核磁和热重法(TG)分别表征了WPU和HEMA-WPU的分子结构及其热分解行为。结果表明,与WPU相比,HEMA-WPU的耐热性能明显提高,用该乳液上胶处理后的碳纤维/环氧树脂复合材料的层间剪切强度(ILSS)与未上胶的样品相比提高了7.5%,达到64.5 MPa。     

二-(4-羟基丁基)聚二甲基硅氧烷改性聚氨酯/脲的合成及性能研究

以二-(4-羟基丁基)聚二甲基硅氧烷(HB-PDMS)和聚乙二醇为(PEG)软段,2,4-甲苯二异氰酸酯(TDI)为硬段,合成了一系列不同硬段含量的聚氨酯/脲(PU)和有机硅改性聚氨酯/脲(SiPU)。通过FT-IR、DSC、TG及吸水率表征了PU和SiPU的结构及性能。结果表明,相对于PU,SiPU的耐水性随SiPU中HB-PDMS含量的增大而逐渐增强,聚硅氧烷的引入虽然降低了PU的初始热降解温度,但其在高温区的热稳定性增强。     

Properties Study of Poly(L-lactic acid)/Polyurethane-Blend Film

Poly(L-lactic acid) (PLLA)/polyurethane (PU)-blend films were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLLA/PU-blend films were investigated by scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PLLA/PU-blend films were studied by differential scanning calorimetry (DSC), tensile tests, and contact angle testing. It was indicated that the addition of PU could exert marked effects on the properties of PLLA films.     

Preparation and characterization of waterborne polyurethane/silica hybrid dispersions from castor oil polyols obtained by glycolysis poly(ethylene terephthalate) waste

Castor oil polyols (COLs) have been synthesized from glycolyzed oligoester polyol in order to produce waterborne polyurethane (WPU)/silica hybrid dispersions. Soft drinks poly(ethylene terephthalate) (PET) bottles were depolymerized by glycolysis with different molar ratio of poly(ethylene glycol) ( PEG 400), in the presence of zinc acetate as catalyst. The obtained glycolyzed products were reacted with castor oil (CO) to attain castor oil polyols by the process of transesterification. Five castor oil polyols were used with hydroxyl values of 255, 275, 326, 366 and 426 mg KOH g⁻¹. Several castor oil-based, polyurethane/silica hybrid dispersions having soft segment content of 39.6% to 28.2% and two concentrations of SiO₂ nanoparticles (0.5 and 1.0) have been prepared.The incorporation effect of SiO₂ nanoparticles into the PU matrix and the hydroxyl functionality of the COLs on the thermal and mechanical properties of resulting polyurethane films has been examined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TG) and measurement of the mechanical properties. The degree of phase separation (DPS) between oxide nanoparticles and hard segment, and particle size in the polyurethane, depends to some extent on nanosilica content and the hydroxyl functionality of the polyols employed in the polyurethane preparation process.Thermal stability of obtained hybrid materials depends on the hydroxyl functionality of the COLs and nanosilica content. The T_10% and T_50% (the temperature where 10 and 50% weight loss occurred) of WPU films decreased with the rise of OH functionality of castor oil polyols, caused by the increase of hard segment content. Glass transition temperature increased with increasing OH functionality and SiO₂ content. The hardness, adhesion and gloss quality of the polyurethane films were also determined with a view to assessing the effect of mole ratios of PET to glycol in glycolyzed products, the hydroxyl functionality and the SiO₂ content.     

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。     

改性纳米SiO2/聚氨酯-含氟丙烯酸酯无皂乳液合成及其胶膜性能表征

引言水性聚氨酯相对溶剂型聚氨酯具有不燃、气味小、不污染环境等优点[1-2],从而广泛用于涂料[3]、胶黏剂[4]、油墨[5]等领域。目前,常用于软包装领域的薄膜主要是表面能很低的非极性膜,而水性聚氨酯胶黏剂具有较高的表面自由能,对非极性膜的润湿性差,因此需要降低水性聚氨酯的表面张力,达到润湿非极性膜的目的。     

醋酸纤维素改性水性聚氨酯的制备及性能

以醋酸纤维素(CDA)、异佛尔酮二异氰酸酯(IPDI)、聚醚2000(PPG2000)为主要原料,二月桂酸二丁基锡(DBTDL)为催化剂,二羟甲基丙酸(DMPA)为亲水扩链剂制备了一系列CDA改性的水性聚氨酯(WPU)。研究了CDA的乙酰基含量及CDA用量对乳液的粒径、黏度及对胶膜的力学性能、耐磨性、硬度的影响。利用红外光谱(FT-IR)及热重分析(TG)研究了胶膜的性能。结果表明:当CDA的乙酰基含量为43.5%,CDA的用量为6.8%,DMPA的用量为6.67%时,改性后胶膜的综合性能比较好。FT-IR表明,CDA成功接枝到PU分子骨架上;TG结果表明,CDA改性PU后,胶膜的热稳定得到明显提高。     

Improved corrosion resistance based on APTES-grafted reduced sulfonated graphene/waterborne polyurethane coatings

In this work, reduced sulfonated graphene (RSG) containing free amine groups was prepared and modified by 3-aminopropyltriethoxysilane (APTES) and reduction by diethanolamine (DEA). In addition, waterborne polyurethane (WPU) composite coatings were prepared by adding RSG as an anticorrosive filler to WPU. From the results of Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy (SEM), it can be found that sulfonated graphene was modified with APTES and successfully reduced by DEA. The SEM images illustrated that RSG was uniformly doped in the WPU. With increasing RSG content, the hydrophobicity of the RSG/WPU films increased due to the strong covalent interaction between RSG and WPU. Finally, the corrosion resistance of the coating was characterized by polarization curves and salt spray tests.     

硅烷偶联剂改性氧化石墨烯/水性聚氨酯复合物的合成与性能

采用改进的Hummers方法制得氧化石墨烯(GO),利用硅烷偶联剂改性氧化石墨烯后经氨水还原得到硅烷化还原氧化石墨烯(KRGO),再与水性聚氨酯(WPU)预聚体复合得到KRGO/WPU复合物。采用FTIR、XRD、SEM、TEM、TGA和电子万用机对复合物的结构和性能进行表征。结果表明,KRGO/WPU复合物热稳定性较纯WPU有所提高,KRGO/WPU-1质量损失为5%时的温度(T5%)比WPU大约高20℃;随着KRGO质量分数的增加,复合材料的拉伸强度先增大后减小,当KRGO质量分数为0.5%时,KRGO/WPU复合物的拉伸强度达到最大值(20.2 MPa),较纯WPU(10.8 MPa)提高了187.1%;另外,KRGO/WPU复合材料疏水性能较纯WPU也有明显改善。     

聚酯聚醚混合二元醇对水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯(IPDI)和异佛尔酮二胺(IPDA)为硬段,分别以聚四氢呋喃二醇(PTMEG2000)、聚己二酸新戊二醇酯二醇(PNA2000)及其混合物为软段,制备了系列水性聚氨酯(WPU)乳液.通过ATR-FTIR对聚氨酯结构进行了表征分析,采用拉伸测试、热失重分析、动态力学分析及耐水性测试等手段对WP U胶...