Emulsifyable air drying urethane alkyds

A novel monomer, acrylamido (A) tertiary (T) butane (B) sulfonic (S) acid (ATBS) a commercially available ionic moiety was used as a replacement of dimethylol propionic acid (DMPA) in synthesis of polyurethane dispersion. IR technique was used to confirm the chemical structure and formation of polyurethane dispersions. Polyurethane dispersions were investigated for various coating properties, such as drying times, pencil hardness, adhesion, chemical and solvent resistance. Polyurethane dispersion based on ATBS showed better thermal, chemical and coating properties than those prepared by DMPA anionomer.     

Preparation and characterization of thermoplastic water‐borne polycarbonate‐based polyurethane dispersions and cast films

Stable water‐borne polyurethane dispersions (PUDs) were prepared from bifunctional aliphatic polycarbonate‐based macrodiol, 2,2‐bis(hydroxymethyl)propionic acid (DMPA), 1,6‐diisocyanatohexane, 1,4‐butanediol (BD), and triethylamine. Water‐borne dispersion particles are thus solely formed from self‐assembled linear PU chains. Both PUDs and PUD‐based films were characterized with regards to the concentration of DMPA (ionic species content) and BD (hard‐segment content). Average particle size of PUDs decreased and their long‐term stability increased with increasing DMPA and decreasing BD concentration. Functional properties of cast films made from PUDs are substantially influenced by the character of the original colloidal particle dispersions. The swelling behavior of the films, their surface morphology, and mechanical properties are more influenced by DMPA than BD contents. At DMPA concentrations higher than 0.2 mmol g^?1 of the solid mass of polyurethane, distinct self‐organization of individual nanoparticles into fibril‐like structures was detected by atomic force microscopy and scanning electron microscopy. PU films made from PUD containing high BD as well as high DMPA concentrations have the best utility properties namely sufficient tensile properties and a very low swelling ability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42672.     

Selection of coalescing solvents for coatings derived from polyurethane dispersions utilizing high throughput research methods

Reduction of volatile organic compounds (VOCs) in coatings is being driven by regulation and consumer preference. Development of binders that are capable of delivering expected performance at low VOC is a major thrust of coatings research and development. Toward this end, polyurethane dispersions (PUDs) from natural oil polyester polyols (NOPs) have been developed. These hydrophobic NOP-based PUD coatings exhibit exceptional early water resistance and hydrolytic stability, excellent acid resistance, and good toughness & abrasion resistance. Most high performance PUDs require large amounts of solvent to form crack-free films with good properties. However, with the right choice of process and solvent parameters, PUDs have been shown to require reduced amounts of coalescing solvents to yield the desirable array of end-user properties with ambient temperature drying. High-throughput research (HTR) was used as a means to accelerate formulation and product development of PUDs. Rapid formulation and testing allows for probing of interactions between variables in greater depth and breadth than conventional formulation techniques, leading to rapid development of robust products and formulations. The HTR methods for coatings applications include the use of specially designed experiments, robotic formulation, coating, and characterization tools as well as informatics for data visualization, extraction, and modeling. This paper details the use of HTR capability to explore the effect of cosolvents on end-use properties of NOP based PUD coatings as well as the proposed mechanisms of film formation in NOP-PUDs. The results provide a basis for guidelines for selection of cosolvents for PUD coatings with high performance and low VOC (<100 g/L VOC).     

Surface modification with waterborne fluorinated anionic polyurethane dispersions

Waterborne fluorinated anionic polyurethane dispersions (FAPUDs) were synthesized from tris(6‐isocyanatohexyl) isocyanurate, N‐ethyl‐N‐2‐hydroxyethyl‐perfluorooctanesulfonamide, poly(oxytetramethylene glycol) (PTMG), dimethylolpropionic acid (DMPA), hexamethylene diisocyanate, 1,4‐butanediol, and two different neutralizing agents (triethylamine and sodium carbonate). Waterborne polyurethane dispersions (PUDs) were synthesized from isophorone diisocyanate, PTMG, DMPA, and ethylenediamine as chain extenders. The particle size of the FAPUDs, based on the fluorine content and degree of neutralization (DN), was measured with dynamic light scattering. So that the surface modification and morphology variations of the PUDs through the addition of the FAPUDs could be observed, the surface energy and thermal properties of the blending films [fluorine PUD mixtures (FPMs)] were measured with contact‐angle analysis and differential scanning calorimetry. The particle size of the FAPUDs increased as the fluorine content in the FAPUDs increased and decreased as the DN increased. The surface energy of the FPM films made from the blending of the FAPUD T series (neutralization with triethylamine) gradually decreased above the critical fluorine concentration (0.02797 wt %). However, for the blending of the FAPUD 25Na series (neutralization with sodium carbonate), the surface energy increased above the critical fluorine concentration (0.02797 wt %) because of the increase in Na salts. The FAPUDs showed the native thermal behavior of the fluorine. However, the thermal properties of the blending films were like those of pure PUDs. This showed that the morphology of the PUDs was rarely unchanged when the FAPUDs were added. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3322–3330, 2002     

含有磺酸基/羧基高固含量聚氨酯分散体的合成与表征

以磺酸盐聚醚二元醇(SPPG)作为软段亲水单体,DMPA作为硬段亲水单体,聚己二酸己二醇新戊二醇酯(PHNA)、异佛尔酮二异氰酸酯(IPDI)、六亚甲基二异氰酸酯(HDI)、三乙胺(TEA)、哌嗪为原料,采用丙酮法合成了固含量50%以上软硬段均含亲水的聚氨酯分散体(PUD)。研究表明,PUD的ζ电位处于-52～-72mV之间,具有良好的稳定性。亲水基团含量(HGC)、HDI/IPDI摩尔比的增加使胶粒平均粒径变小,粒径分布变窄,黏度增加;—SO3Na/—COOH摩尔比的减小,使小粒子体积分数在21%～28%,黏度显著减小。透射电镜(TEM)显示,分散体胶粒多为大小不一的球形结构,呈多元分布。DMA显示PUD胶膜具有良好的软硬段相容性和耐寒性。     

不同软段结构的磺酸盐阴/非离子型高固含量聚氨酯分散体的研究

以磺酸盐聚醚二元醇和聚乙二醇单甲醚作为亲水单体,不同软段结构的多元醇、异佛尔酮二异氰酸酯(IPDI),乙二胺(EDA)为原料,采用预聚体法制备固含量50%以上的聚氨酯分散体(PUD).研究表明:PUD的ζ电位处于-50～-80 mV之间,分散体具有良好稳定性.平均粒径处于100～140 nm之间,粒径多分布于90～160 nm范围内.透射电镜(TEM)表征显示:分散体胶粒呈大小不一的球形结构.PUD的黏度随剪切速率的增加而下降,呈现假塑性流体的特征.PCDL/PTMG基PUD膜具有优良的耐水性和力学性能.     

Polyester polyols for waterborne polyurethanes and hybrid dispersions

In this study, environmentally friendly polyester based polyurethane dispersions (PUDs) were synthesized using various combinations of isophthalic acid, adipid acid and maleic anhydride (IPA-AA-MA). A triangular empirical model was employed to optimize total number of experiments for optimal performance of polyurethane dispersions. In addition to PUDs, polyurethane/acrylate hybrid dispersions (PU/AC) were synthesized using graft copolymerization method to enhance the performance/properties of PUDs and for potential cost benefit.     

Synthesis of high‐solid content sulfonate‐type polyurethane dispersion by pellet process

A novel method to prepare polyurethane dispersions (PUDs) is introduced in this article. Water dispersible polyurethane ionomer pellets were synthesized without solvent; these pellets were then dissolved in acetone and dispersed in water. Then PUDs were obtained after acetone was distilled off. Polyurethane ionomers were synthesized from polyether diol containing sulfonate as hydrophilic monomer and poly(1,4‐butylene adipate glycol) with an average molecular weight of 3000 as soft segments, isophorone diisocyanate and 1,4‐butanediol as hard segments, and dibutyltin dilaurate as catalyst. The properties of PUDs were measured by Laser particle size analyzer, Brookfield viscosity, and TEM analysis. High‐solid content and low viscosity PUDs were obtained. Meanwhile, PUDs exhibited excellent stability and polydispersity according to the above analysis. Tensile tests and dynamic mechanical analysis showed good mechanical and thermodynamic properties of PUD films. Some typical characteristics of crystalline polymers were revealed in the tensile stress–strain curves of PUD films. Peel strength test (PVC/PVC) yielded a maximum initial peel strength value of 6 N/mm and T‐peel strength value of 10 N/mm. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Stimuli-Responsive Polyurethane Dispersions – Aqueous Auto-Dispersion

We report a single-pot synthesis of polyurethanes (PUs) in solvent that utilizes an hydroxyl imidazolium bromide salt (ionic liquid) as a chain terminating group. This material, after being desolvated under activation, spontaneously disperses in water to form auto-dispersing polyurethane dispersions (PUDs). These PUDs comprise aggregates, that separate under further activation (sonication) to form sub-micron to sub-100-nm dispersions that are stable. Their size changes during such (auto) dispersion processing are examined by dynamic light scattering. Anion-dependent stimuli-responsiveness is observed upon anion exchange. This stimuli-responsiveness is based on imidazolium-anion pair solubility changes induced by anion exchange. Dispersion destabilization can be induced by selection and anion exchange for particular “hydrophobic” anions. Film formation and wetting are observed to exhibit stimuli-responsiveness to anion exchange. Coatings based on PUD comprising tripropylene glycol are less hydrophilic than coatings incorporating PEO-based PUDs.     

水性聚氨酯的交联改性及其性能

阴离子水性聚氨酯(PU)含有羧基起内乳化剂作用稳定水性聚氨酯分散体(PUD),同时也使PU膜具有高的亲水性.为提高PUD涂膜性能,采用氮丙啶和聚碳化二亚胺对其进行交联改性.利用红外光谱和热重分析表征了PUD固化涂膜,结果表明:在室温下氮丙啶和聚碳化二亚胺可与PUD链上的羧基反应,PUD涂膜性能的提高取决于固化剂种类:如氮丙啶能显著改善涂膜耐水性、耐溶剂性及耐污染性,因其能提高涂膜的凝胶含量至92.63%,涂膜硬度至0.72,其最佳的氮丙啶与羧基的质量比为5.84;另一方面,聚碳化二亚胺能改善涂膜的附着力、柔韧性及抗冷脆性,最佳的聚碳化二亚胺与羧基的质量比为10.37.TGA曲线表明聚碳化二亚胺能提高PUD涂膜的热稳定性,而氮丙啶则降低涂膜的热稳定性.     

Synthesis and characterization of low crystalline waterborne polyurethane for potential application in water-based ink binder

Waterborne polyurethane dispersions (PUDs) with low crystallization and narrow nanoparticles distribution were synthesized from poly(propylene glycol) (PPG), isophorone diisocyanate (IPDI), dimethylolpropionic acid (DMPA) via a environmental and simple process combined prepolymer isocyanate process with acetone process. For used as ink binder, the acid numbers of PUDs were analyzed. It was found that the acid number changed with the solid content and mainly increased with increasing hard-/soft-segment molar ratio. Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance spectroscopy (¹H NMR), transmission electron microscope (TEM), differential scanning calorimetry (DSC), thermogravimetric (TG), X-ray diffractometer (XRD) and polarizing optical microscopy (POM) measurements were utilized to characterize the bulk structures and thermal properties of PUDs. The results show that nanoscale waterborne polyurethane dispersions synthesized through the combined process have good thermal stability and weakly crystallinity, which is suitable for the use of water-based ink binder. The performance of PUDs can be optimized for the application as ink binder when the hard-/soft-segment molar ratio is 4 or 5.     

二羟甲基丙酸用量对聚氨酯-丙烯酸酯离聚物乳液性能的影响

用甲苯二异氰酸酯、聚己二酸新戊二醇酯多元醇(PDGA)、二羟甲基丙酸(DMPA)和甲基丙烯酸-2-羟乙酯合成了聚氨酯-丙烯酸酯(PUA)离聚物乳液,讨论了DMPA用量对其性能的影响。结果表明,当DMPA与PDGA的摩尔比增大时,PUA离聚物乳液的平均粒径减小,粒径分布变窄,黏度增大,稳定性提高,但DMPA用量过高时,会使具有高表面能的小粒子团聚,从而给PUA离聚物的乳液性能带来负面影响。     

Automated parallel polyurethane dispersion synthesis and characterization

The synthesis of waterborne polyurethane dispersions (PUDs) using an automated parallel reactor system was explored. Waterborne PUDs are an important class of polymer dispersion that can be used in many applications such as coatings for wood finishing, glass fiber sizing, adhesives, automotive topcoats, and other applications. Herein, we present the synthesis of aqueous PUDs using a Chemspeed Autoplant A100™ automated parallel reactor system. This is the first time a PUD has been synthesized using an automated parallel reactor system. The synthesis involves the formation of an isocyanate-terminated prepolymer followed by neutralization, dispersion in water, and chain extension. Details of the methodology are discussed with respect to the process of writing the program for the synthesis to synthesizing the PUD itself with the Chemspeed. It is demonstrated that an aqueous PUD can be synthesized with an automated parallel process and the unit-to-unit results are similar. Process variables such as agitator design, rate of neutralization, and rate of water dispersion are varied as these are the three major factors which lead to the desired end product property. The controlled addition of neutralizer, water, and chain extender is an added advantage with this automated technique and gave consistent results in all the units. The PUDs were characterized for their particle size, viscosity, and percent solids.     

Aqueous dispersion of polyurethane anionomers from H12MDI/IPDI,PCL, BD,and DMPA

Polyurethane anionomer dispersions were prepared from hydrogenated diphenylmethane diisocyanate (H₁₂MDI) or isophorone diisocyanate (JPDI), poly(caprolactone) (PCL) diol, 1,4-butane diol (BD), and dimethylolpropionic acid (DMPA). Upon neutralization of the DMPA with triethylamine (TEA), the NCO-terminated polyurethane (PU) ionomers were self-emulsified by adding water, followed by chain extension using triethylenetetramine (TETA) in aqueous media. Polyurethanes from H₁₂MDI showed coarser dispersion and better tensile properties over those from IPDI. Polyurethanes prepared by the one-shot method had better dispersion and tensile properties over those by the two-shot method. When some of the PCL diol was replaced by DMPA or BD, tensile strength increased and ductility decreased due mainly to the increased chain rigidity and intermolecular forces. © 1994 John Wiley & Sons, Inc.     

Effect of counterion on the properties of anionic waterborne polyurethane dispersions developed from cottonseed oil based polyol

A series of maleated cottonseed oil polyol (MAHCSO) based, DMPA (dimethylol propionic acid) free, catalyst free waterborne polyurethane dispersions (PUDs) were synthesized. Four different tertiary amines, were employed as neutralizing agents to investigate the role of countercation on the physico-chemical properties of PUDs and their corresponding cured films. The developed PUDs were characterized by particle size analysis, zeta potential distribution, viscosity and storage stability and the cured film samples were characterized by FT-IR (ATR), DMTA (Dynamic mechanical and thermal analysis), UTM (Universal testing machine) and contact angle analyses. It was found that the waterborne PUD with countercation having more number of hydroxy alkyl chains exhibit a larger particle size, a less negative zeta potential, higher viscosity and lower storage stability, where as the corresponding cured film possesses lower thermal stability, mechanical strength and poor surface properties.

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Graphical abstract Synopsis: Cottonseed oil based ionisable polyol was synthesized by insitu ring opening hydrolysis of epoxy cotton seed oil (ECSO) followed by maleanisation to introduce carboxylic groups. The maleated polyol was used as ionic soft segment to synthesize four types of waterborne polyurethane dispersions (PUDs) using different neutralizing agents.

     

Air-drying bio-based polyurethane dispersion from cardanol: Synthesis and characterization of coatings

Exploring bio-renewable materials to replace petroleum-based building blocks for advanced coatings has been a major thrust area for researchers for the development of eco-friendly and sustainable products. For the last few decades, there has been significant interest among coating researchers around the world to design water-based polyurethane dispersions (PUDs) that can be cured at ambient conditions. In the present work we synthesized auto-oxidizable PUDs based on cardanol as sustainable material that also provides self-crosslinking attribute to the PUDs. Such types of PUDs are expected to be suitable for water-based industrial protective primers. The cardanol-based intermediates and final products are characterized by FTIR spectroscopy for conformation of synthesis reaction and their structures. The dried films of the coatings, formulated using a suitable drier catalyst, exhibited improvement in mechanical properties and solvent resistance. The oxidative curing has also been investigated by FTIR and differential scanning calorimetry (DSC). The corrosion resistance properties of the coatings on steel substrate, as studied by using electrochemical impedance spectroscopy (EIS) technique also showed better performance for cross-linked films.     

基于磺酸基/羧基高固含量聚氨酯分散体膜性能的研究

以磺酸盐聚醚二元醇(SPPG)和二羟甲基丙酸(DMPA)作为亲水单体,以聚己二酸己二醇新戊二醇酯(PHNA)、异佛尔酮二异氰酸酯(IPDI)、六亚甲基二异氰酸酯(HDI)、哌嗪为原料,采用丙酮法合成了固含量(固体质量分数,以下同)50%左右的聚氨酯分散体(PUD)。研究表明,PUD平均粒径在100～250 nm,黏度均在650mPa.s以下,PUD胶膜的断裂伸长率最高可达2 400%,拉伸强度最大为15 MPa;动态力学分析表明,胶膜的玻璃化温度在-50～-35℃,随n(—NCO)/n(—OH)增加,PUD胶膜的玻璃化转变温度升高;热重分析显示,PUD胶膜在280℃开始分解,PUD胶膜的吸水率在3%～7%。     

Polyurethane–urea anionomer dispersions. I

Polyurethane–urea anionomer dispersions with different stoichiometric DMPA/polyol and NCO/OH ratios were preapred from poly(oxypropylene)glycol, toluene diisocyanate (TDI), dimethylolpropionic acid (DMPA), and ethylenediamine (EDA). The dispersion-cast films were prepared and characterized by mechanical properties, dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC). Increasing the hard-segment content by either increasing the DMPA/polyol or the NCO/OH ratios affects the glass transition temperature (T_g) of the soft segments. © 1994 John Wiley & Sons, Inc.     

基于芳香族聚酯的磺酸盐型聚氨酯分散体的合成与表征

以磺酸盐聚醚二元醇(SPPG)为亲水单体,聚邻苯二甲酸酐己二醇酯(PHPA)、六亚甲基二异氰酸酯(HDI)和乙二胺(EDA)为原料,采用丙酮法合成了固含量50%以上的芳香聚酯型聚氨酯分散体(PUD)。研究表明,分散体表面张力处于34~45 m N/m,对基材有较好的润湿能力;PUD平均粒径100~250 nm,粒径分布多处于50~200 nm,具有良好的稳定性。分散体表面张力、平均粒径、黏度、粒径分布受亲水基团含量、R值和扩链度的影响,呈现一定变化规律。透射电镜(TEM)显示,PUD胶粒为大小不一的球形结构,呈二元分布。分散体呈假塑性流体特征。黏合强度测试表明,样品对不同种类的PVC、木材具有良好的黏合性能。     

Preparation and Properties of Water-borne Polyurethanes

Following a prepolymer mixing process, polyurethane (PU) anionomer dispersions were prepared from polyethylene adipate glycol (PEA), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI) and dimethylol propionic acid (DMPA) as a potential ionic centre. Effects of prepolymer molecular weight, PEA molecular weight, hard segment content, DMPA content, degree of neutralization and mixed diisocyanates have been studied in terms of particle size and viscosity of emulsion, and surface, mechanical and dynamic mechanical properties of the emulsion-cast films. Particle size decreased and emulsion viscosity increased with increase in prepolymer molecular weight and PEA molecular weight, DMPA content, the degree of neutralization and IPDI content in mixed isocyanate systems. The decrease in particle size was due to increased chain flexibility and/or hydrophilicity of the PU. The mechanical and dynamic mechanical properties of the PU ionomer dispersions were interpreted in terms of soft segment–hard segment phase separations, hard segment content, chain flexibility and coulombic forces. © of SCI.