Maleopimaric acid‐modified two‐component waterborne polyurethane for coating applications

Maleopimaric acid (MPA), an important rosin derivative, was used to partially substitute isophthalic acid for the preparation of an anionic polyol (MPP) dispersion. The MPP dispersion was then applied to prepare a novel maleopimaric acid‐modified two‐component waterborne polyurethane (MPP‐2K‐WPU). The influences of NCO:OH molar ratio on the thermal properties, water absorption, surface free energy, and application properties of MPP‐2K‐WPU films were investigated. With increasing NCO:OH molar ratio, the thermal stability, pencil hardness, and ethanol resistance of MPP‐2K‐WPU films were improved, but the water resistance was enhanced firstly and then weakened. The surface free energy of MPP‐2K‐WPU films mainly depended on the dispersion interaction which was related to the structure of macromolecules. In addition, compared with the control sample of PP‐2K‐WPU(1.5:1) film, the MPP‐2K‐WPU(1.5:1) film exhibited improved thermal stability, water resistance, gloss, pencil hardness, and ethanol resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43292.     

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。     

Preparation and characterization of a polydimethylsiloxane‐modified,epoxy‐resin‐based polyol dispersion and its crosslinked films

Waterborne polydimethylsiloxane‐modified epoxy‐resin‐based polyol dispersions were synthesized by the reaction of 2,4‐toluene diisocyanate with 2,2‐bis(hydroxymethyl) propionic acid, hydroxypropyl‐terminated polydimethylsiloxane (HTPDMS), and bisphenol A epoxy resin based polyol. These HTPDMS‐modified polyol dispersions exhibited a small particle size and an excellent dispersion stability. Two‐component waterborne polyurethane (2K‐WPU) was prepared from the HTPDMS‐modified polyol dispersion and a hydrophilic‐modified polyisocyanate. The structure of the HTPDMS‐modified polyol and its crosslinked 2K‐WPU films (SEFs) were characterized with Fourier transform infrared and NMR spectroscopies. The effects of the HTPDMS content on the mechanical and thermal properties of the resulting SEFs were investigated. The results show that the thermal stability of the crosslinked SEFs was enhanced with increasing HTPDMS content, whereas the modulus, tensile strength, and pencil hardness values of the films decreased with increasing HTPDMS content. Siloxane segments migrated onto the surface during the film‐formation process. The contact angle of the films increased from 71 to 96 °, and the water absorption ratio of the films decreased from 6.6 to 5.0% when the HTPDMS content in the films increased from 0 to 10%. These results indicate that the water resistance of the films was enhanced by the introduction of HTPDMS into the 2K‐WPU networks. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44342.     

Crosslinking reaction and properties of two‐component waterborne polyurethane from terpene‐maleic ester type epoxy resin

A two‐component waterborne polyurethane (2K‐WPU) is prepared with the terpene‐maleic ester type epoxy resin‐based polyol dispersion and a hydrophilically modified hexamethylene diisocyanate tripolymer. Laser particle size analyzer and transmission electron microscopy are used to characterize the particle size distribution and the micromorphology of the 2K‐WPU. Crosslinking reaction kinetics of the 2K‐WPU is examined by fourier transform infrared spectrometry (FTIR) spectra. In the preliminary stage of the crosslinking reaction, it shows a very good fit with a second order reaction kinetics, and the apparent activation energy is 94.61 kJ mol^?1. It is also shown from the FTIR spectra that the complete crosslinking reaction of the 2K‐WPU needs 7 h at 70°C. The crosslinked products of the 2K‐WPU have good thermal resistant properties, with glass‐transition temperatures (T_g) in the range of 35–40°C and 10% weight loss temperatures (T_d) in the range of 275–287°C. The films obtained from the crosslinked products have good water‐resistance, antifouling, blocking resistance properties and impact strength of >50 cm, flexibility of 0.5 mm, adhesion of 1 grade, pencil hardness of HB‐2H. The pencil hardness and thermal‐resistant properties of the crosslinked products increase with the molar ratio of isocyanate (? NCO) group to hydroxyl (? OH) group. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effects of the reagent molar ratio on the phase separation and properties of waterborne polyurethane for application in a water‐based ink binder

Waterborne polyurethane (WPU) dispersions with a high solid content and low viscosity were prepared successfully by a two‐step polymerization with isophorone diisocyanate, poly(propylene glycol), and dimethylol propionic acid as the main raw materials. The molar ratio of hard segments to soft segments was controlled to investigate its influence on the particle size, particle morphology, stability of dispersions, and final properties of the WPU films. Measurements including attenuated total reflectance/Fourier transform infrared spectroscopy, transmission electron microscopy, differential scanning calorimetry, thermogravimetric analysis, X‐ray diffraction, polarizing optical microscopy, and contact angle tests were used to characterize the bulk structures, phase separation, thermal stability, crystallinity, and wettability of the WPU dispersions. The results indicate that all of the WPU dispersions with a high solid content (ca. 40 wt %) and low viscosity (ca. 20–50 mPa s) displayed excellent stability. The prepared WPU dispersions with acetone contents of 5–7 wt % could be used directly as an ink binder without removing the acetone; this is beneficial to industrial applications of water‐based ink binders. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45406.     

Properties and paper sizing application of waterborne polyurethanemicroemulsions: Effects of extender,cross‐linker,and polyol

A series of waterborne polyurethane (WPU) microemulsions were synthesized through self‐emulsification methodology, using toluene‐2,6‐diisocyanate, polytetramethylene glycol (PTMG), poly‐caprolactonediol (PCL), and dimethylol propionic acid (DMPA) as monomers; isophorone diamine (IPDA) as chain extender; and aziridine as cross‐linking agent. The resultant WPU microemulsions were utilized as surface‐sizing agents for cellulose fiber paper. The influences of IPDA content, PTMG/PCL molar ratio, and aziridine content on the physicochemical properties of the resultant emulsions and sized paper have been investigated in detail. The WPU microemulsion displayed better surface sizing properties when it was prepared under the following conditions: the IPDA content of 2.96%, PTMG/PCL molar ratio of 0:4, and aziridine content of 2.0 wt %. The relationships between the WPU structure and properties of WPU films and sized paper were clearly illustrated. The mechanical properties and water resistance of sized paper were not only depended on the interactions, chain entanglements, and cross‐linking density among the WPU chains, but also relied on the interactions among polymers and fibers, as well as the polarity and stiffness of surface sizing agent. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43211.     

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。     

高性能水性UV固化聚氨酯的合成与性能研究

用环氧丙烯酸酯(EA)、羟基硅油合成了环氧/有机硅改性水性光固化聚氨酯乳液(WPU);研究了EA、羟基硅油、亲水扩链剂二羟甲基丁酸(DMBA)的用量,中和度和硅烷偶联剂的添加量对乳液和涂膜性能的影响。用红外光谱和接触角测量仪对树脂进行表征。结果表明:通过EA、羟基硅油改性的水性光固化聚氨酯涂膜的硬度高、附着力强、耐水性较好,克服了未改性水性光固化聚氨酯的缺点。当EA用量为4%、羟基硅油为2%、DMBA为8%、中和度为80%、硅烷偶联剂的添加量为1%时,水性光固化聚氨酯乳液的综合性能较好,树脂接触角大大提高。     

The physical properties of nonionic waterborne polyurethane with a polyether as side chain

A series of nonionic waterborne polyurethanes (WPU) based on hydrogenated methylene diphenylene diisocyanate, polybutylene succinate diol, polybutylene adipate diol, polyethylene glycol, and diethylene glycol as chain extender were synthesized with a polyether, MPEG‐(OH)₂, as side chain. The physical properties such as tensile strength, elongation, hardness, molecular weight, kinetic viscosity, and so on were detected. The WPUs made with polyesters have the best tensile strength but the lowest elongation. Because of the hydrophilic property of MPEG‐(OH)₂ grafted on the WPUs, they have obvious increases of solid contents and water absorptions with the ratio of MPEG‐(OH)₂. The functional group ratio of NCO/OH is another reason affecting the hydrophilic properties of the WPUs. In addition, the water ratios of the dispersions dramatically affect the stability of WPU systems. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

环氧改性水性聚氨酯涂料的合成与性能研究

采用环氧树脂与聚醚、二羟甲基丙酸（DMPA）和甲苯二异氰酸酯（TDI）反应制备水性聚氨酯涂料。研究发现随着所用的环氧树脂的环氧值的降低，改性水性聚氨酯涂膜的硬度和拉伸强度逐渐提高，断裂伸长率则随着降低。选用环氧值为0．44的环氧树脂所合成的改性水性聚氨酯的涂膜硬度达到玻璃硬度0．70；随着环氧树脂添加量增大，涂膜机械性能增加。采用后添加环氧树脂的合成工艺，可制备贮存稳定的水性聚氨酯乳液；凝胶渗透色谱（GPC）分析表明环氧树脂改性水性聚氨酯提高了聚氨酯的分子量。性能测试表明环氧改性水性聚氨酯涂料具有涂膜硬度高、耐水性好和耐溶剂性好等优点。     

Transparent polyester polyol-based polyurethane coatings: the effect of alcohols

A series of polyester polyols were synthesized using 1,6-hexanediol (HDO), 1,4-cyclohexanedimethanol (1,4-CHDM) and trimethylol propane (TMP), alone or in combination with 1,4-cyclohexanedicarboxylic acid and adipic acid. The polyester polyols were reacted with isocyanate trimers to form polyurethane (PU) coatings. Physical properties of the polyesters such as hydroxyl value, acid value, molecular weight, viscosity, and glass transition temperature (T _g) had been determined, and the IR spectroscopic analyses of polyesters/PU were reported. The properties (impact resistance, film flexibility, hardness, optical transmittance, chemical resistance, water absorption, thermostability, and phase separation) of the PU coatings so prepared were characterized. The viscosities of polyester polyols were dependent on the structure of the alcohols. Polyester polyol containing only linear aliphatic diol (HDO) was a transparent liquid at room temperature. The viscosity was increased by raising the molar ratio of 1,4-CHDM and/or TMP. All PU coatings had excellent flexibility, impact resistance, and hardness. The coatings derived from diol CHDM had the highest hardness, and the PU derived from diol HDO had the lowest hardness. The chemical resistance and water absorption improved with greater molar ratios of 1,4-CHDM or TMP. Results of differential scanning calorimetry and wide-angle X-ray diffraction indicated that there was no obvious crystallinity in the PU networks. Dynamic mechanical analysis (DMA) results revealed that both CHDM and TMP can increase the T _g of PU, and the crosslinking density improved with increased molar ratio of TMP. Atomic force microscope (AFM) and DMA analysis revealed that the PU coatings had no obvious microphase separation, which enabled them to have excellent properties, and the different composition in polyols did not have significant influence on transmittance in the visible region. Results of thermogravimetric measurements indicated that all the PU coatings had good thermal stability.     

Synthesis and characterization of ambient-temperature self-crosslinked waterborne polyurethanes with a novel diol chain extender bearing two ketone groups

A series of ambient-temperature self-crosslinked waterborne polyurethanes denoted as WBPUs were successfully synthesized by incorporating a novel diol chain extender bearing two ketone groups, 2,2-bis(4-(2-hydroxypropoxy levulinate)phenyl)-propane (BHLPP), which was prepared using 2,2-bis(4-(2,3-epoxypropoxy)phenyl)-propane and levulinic acid, with 4,4-methylenedicyclohexyl diisocyanate, poly-neopentylene adipate glycol, and dimethylolpropionic acid. After post-adding adipic dihydrazide (ADH), self-crosslinking was achieved by the reaction between the ketone (–CO–) of BHLPP and the hydrazine (–NHNH₂) of ADH during film formation. For comparison, noncrosslinked waterborne polyurethane (WPU) without BHLPP and ADH was prepared. The structure of BHLPP was characterized by IR and NMR. The properties of the WPU and WBPU dispersions were investigated by measuring the stability, particle size, and morphology. The effects of the ratio of n(–NHNH₂)/n(–CO–) and the content of BHLPP were studied in terms of hardness, water resistance, solvent resistance, and thermal properties of WPU and WBPU films. The WBPU dispersions exhibited excellent stability, bimodal distribution, and regular spheroid morphology. The optimal ratio of n(–NHNH₂)/n(–CO–) for ketone–hydrazine self-crosslinking was 0.75:1. Importantly, the WBPU films showed superior hardness, water resistance, solvent resistance, and thermal properties to WPU film.     

端羟基聚丁二烯改性水性聚氨酯的合成与性能

以端羟基聚丁二烯(HTPB)、聚醚二元醇(N-220)、异佛尔酮二异氰酸酯(IPDI)为主要原料,制备了改性水性聚氨酯(WPU)。研究了端羟基聚丁二烯(HTPB)的含量对聚氨酯乳液粒径、贮存稳定性,以及对涂膜耐水性、力学性能、低温柔韧性的影响。结果表明:在预聚反应中,固定总n(—NCO)∶n(—OH)为1.3,w(DMPA)为6%,HTPB添加量在40%(占聚醚N-220的量)以下时,粒径变化不大,乳液稳定性较好;针对不同HTPB添加量,控制好亲水基团的含量,可以获得分散性良好、贮存稳定的聚氨酯乳液;随着HTPB添加量逐渐增大,涂膜的拉伸强度逐渐增大后变小,断裂伸长率和吸水率逐渐减小后变大,低温柔韧性变好。当HTPB添加量在30%左右,涂膜的综合性能最佳。     

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     

卡基材料用水性聚氨酯覆膜胶的合成及应用

以异佛尔酮二异氰酸酯(IPDI)、聚己二酸丁二醇酯(PBA)、聚氧化丙烯二醇(PPG)、聚四氢呋喃二醇(PTMG)、二羟甲基丁酸(DMBA)和甲基丙烯酸-β-羟乙酯(HEMA)等为主要原料,合成了卡基材料用阴离子型WPU(水性聚氨酯)覆膜胶。研究结果表明:采用单因素试验法优选出制备WPU覆膜胶的最优配方是初始R=n(-NCO)/n(-OH)=4、m(PPG):m(PTMG):m(PBA)=10:20:70、w(DMBA)=5.5%和w(HEMA)=4.5%(相对于预聚体用原料总质量而言),此时活泼的-NCO基已被封闭,羟基丙烯酸酯已成功引入到WPU大分子链中;与普通WPU覆膜胶相比,由最优配方制成的WPU覆膜胶的固含量(41%)较高、剥离强度较大且稳定性较佳,将其应用于卡基材料中,可得到高剥离强度和高耐湿热老化性能的覆膜色卡。     

Structure and properties of regenerated cellulose films coated with polyurethane–nitrolignin graft‐IPNs coating

A regenerated cellulose film (RC) was coated with a graft‐IPNs coating, which was composed of castor oil‐based polyurethane and 2.8 wt % nitrolignin (NL), to obtain water‐resistant films. The effects of NCO/OH molar ratio and different polyols, such as 1,4‐butanediol (BDO) and trimethanol propane (TMP), on the structure and properties of the coated RC films were investigated. With an increase of the NCO/OH molar ratio, the tensile strength of the coated films increased, but the water resistivity and size contraction hardly changed. The coated films with TMP exhibited the higher breaking elongation at 1.5 of the NCO/OH molar ratio, while those with BDO have more excellent tensile strength, water resistivity, and dimensional stability. The coated films with the graft‐IPNs coating exhibited superior water resistivity and dimensional stability. The light transmittance of the coated films was more excellent than that of the RC film. Moreover, the results from the IR and electron probe microanalysis (EPMA) showed that the chemical bonding occurred between cellulose and coating, and the introduction of NL plays an important role in the enhancement of the interface adhesion of the coated films. Atomic force microscopy (AFM) depicted the flat and dense surface of the coated films, which restricted the water vapor penetration and the size contraction, resulting in the enhancement of water resistivity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1799–1806, 2002     

Preparation and properties of Waterborne polyurethane/nanosilica composites: A diol as extender with triethoxysilane group

Waterborne polyurethane (WPU) was prepared from toluene diisocyanate, polypropylene glycol, 2,2‐bis(hydroxymethyl)propionic acid and a diol containing triethoxysilane group as the chain extender which was synthesized via Michael addition between 3‐triethoxysilylpropylamine and 2‐hydroxyethylacrylate. Different amounts of nanosilica were incorporated into the WPU to prepare WPU/nanosilica composites. The results showed that the particle size of the emulsions increased and their viscosity decreased first and then increased with increasing the amount of nanosilica. Incorporation of nanosilica into WPU enhanced the water contact angle and thermal stability of the composites films, meanwhile, their tensile strength and hardness increased first and then decreased. However, increasing the amount of nanosilica resulted in reduction in the elongation at break of the films. It suggested that nanosilca was anchored into the side chain of WPU due to the condensation process between the triethoxysilane group in the side chain of WPU molecular and the silanols group on the surface of nanosilica. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40526.     

The effect of acrylate on structure and properties of waterborne polyurethane porous coated fabrics

Porous‐coated fabrics used for synthetic leather were prepared by mechanical foaming method using blends of waterborne polyurethanes (WPUs) and polyacrylate (AC). The effect of AC on structure and properties of WPU/AC coated fabrics was investigated. Fourier transform infrared spectroscopy and differential scanning calorimetry results indicated that there is hydrogen bonding between WPU and AC and the compatibility of the blend system gets worse after AC/WPU ratio is higher than 30/70. Thermogravimetric analysis demonstrated that the thermal stability of porous coatings is improved with increasing AC. Scanning electron microscopy images showed that porous coatings have semi‐open cellular structure with a great number of surface pores and window pores, imparting excellent air permeability and water vapor permeability to coated fabrics. On the basis of morphology analysis, the forming process of cell structure of WPU/AC coated fabrics was proposed. Performance tests showed that the overall performance of coated fabrics is best with AC/WPU ratio ranging from 15/85 to 30/70. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45783.     

Synthesis and properties of waterborne poly(urethane urea)s containing polydimethylsiloxane

To obtain flexible waterborne poly(urethane urea) (WBPU) coatings with functionalities such as shape recovery and water resistance, we synthesized a series of WBPUs by a prepolymer mixing process from hexamethylene diisocyanate, polyol, 2,2‐bis(hydroxymethyl) propionic acid, ethylenediamine, and triethylamine with polyol blends [hydroxyl‐terminated polydimethylsiloxane (PDMS) with a number‐average molecular weight of ≈ 550 and poly(tetramethylene oxide) glycol (PTMG) with a number‐average molecular weight of 650] of different molar ratios. The effects of the PDMS content in PDMS/PTMG on the dynamic thermal and mechanical properties, hardness, tensile properties, water resistance (water absorption, contact angle, and surface energy), and shape‐memory properties of WBPU films were investigated. As the molar percentage of PDMS in WBPUs increased, the storage modulus, tensile strength and modulus, elongation at break, hardness, and shape‐retention rate (30–15%) decreased; however, the water resistance and shape‐recovery rate (80–90%) increased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and properties of UV‐curable waterborne polyurethane–acrylate emulsion

Polyurethane–acrylate oligomer terminated with multiple unsaturated bonds was prepared using isophorone diisocyanate, (IPDI), methylene diphenyl diisocyanate, and polyols as monomers, using 2,2‐dimethylol propionic acid as hydrophilic chain extender, together with pentaerythritol triacrylate (PETA) as end‐capper. The UV‐curable waterborne polyurethane–acrylate (UV‐WPUA) composite emulsion was obtained by mixing the PUA oligomer with certain content of reactive diluents and then dispersing the mixture in water. The molecular structure of the polyurethane prepolymer, PUA oligomer, and UV‐cured polymer was investigated by Fourier transform infrared spectroscopy. The influence of the composition and content of the diluents and end‐capper on UV‐WPUA properties, including the emulsion stability, thermal property, water resistance, adhesion, hardness, glossiness of polymer film were studied. The results show that the WPUA emulsion has excellent stability, and the UV‐cured film features good hardness and remarkable water resistance when PETA is used as end‐capper and the end‐capping ratio of the polyurethane prepolymer is 70% and dipentaerythritol hexaacylate/dipropylene glycol diacrylate (mass ratio 1:1) is used as diluent. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45208.