Polyurethane dispersions derived from polycarbonatediols and m‐di(2‐isocyanatopropyl)benzene

Aqueous polyurethane dispersions derived from various polycarbonatediols, m‐di(2‐isocyanatopropyl)benzene(TMXDI), and various carboxylic diols including dimethylol propionic acid (DMPA), dimethylol butyric acid (DMBA), and a carboxylic polycaprolactonediol (Placcel 205BA) were prepared by a method in which the dispersing procedure was modified to enhance the molecular weight. The NH₂/NCO ratio during chain extension affected the molecular weight of the polyurethanes, significantly, and an optimum ratio of 0.67:1.0 was used. The molecular weight, particle size, tensile properties, and thermal properties of the polyurethane dispersions were investigated. The effect chemical structure of the polycarbonatediols on the properties shows no obvious trend, but the polyurethane dispersions derived from the carboxylic polycaprolactonediol exhibit smaller particle size and softer tensile properties when compared with those derived from DMPA and DMBA. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Aqueous polyurethane dispersions derived from polycarbonatediols

Aqueous polyurethane dispersions derived from polycarbonatediols, isophorone diisocyanate, and carboxylic diols including dimethylol propionic acid and dimethylol butyric acid were prepared. The effect of dispersing procedure is investigated by FT IR, GPC, and the tensile film properties. The polyurethane dispersions prepared by a standard procedure exhibit lower molecular weights due to the overhydrolysis of the NCO groups. The polyurethane dispersions prepared by a modified procedure exhibit significantly higher molecular weights due to more effective chain extension, and their cast films exhibit higher tensile strength. The particle size, tensile properties, thermal properties, and dynamic mechanical properties are investigated. The chemical structure of the polycarbonatediols seems to affect the tensile strength. The glass transition temperature of the soft segments, T_g(S), of the polyurethane dispersions can be seem from the DSC and DMA data. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1723–1729, 2004     

Effect of composition on aqueous polyurethane dispersions derived from polycarbonatediols

Aqueous polyurethane dispersions derived from isophorone diisocyanate, various polycarbonatediols of different molecular weights, and dimethylol butyric acid were prepared by a dispersing procedure modified to enhance molecular weight. Particle size, average molecular weight, and tensile properties were determined. The molar ratio of reactants affected the properties of the polyurethane dispersions significantly, with the trends described as the effects of their ionic group and polycarbonatediol soft‐segment contents. The molecular weight of the polycarbonatediols also significantly affected the particle size of the aqueous polyurethane dispersions and the film properties. As the molecular weight of the polycarbonatediols decreased, the particle size of the aqueous polyurethane dispersions decreased, and the moduli of the cast films increased, as expected. However, the tensile strength of the cast films decreased as the molecular weight of the polycarbonatediols decreased because of the decrease in elongation at break. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4419–4424, 2006     

Clear polyurethane dispersions of nanometer size derived from carboxylic polycaprolactonediols

Aqueous polyurethanes dispersions of nanometer size derived from various carboxylic polycaprolactonediols of different molecular weights, carboxylic diols, including 2,2‐di(hydroxymethyl)propanoic acid (DMPA), 2,2‐di(hydroxymethyl)butanoic acid (DMBA), and di(4‐isocyanatocyclohexyl)methane (HMDI) were prepared by a method in which the dispersing procedure was modified to enhance the molecular weight. The molecular weight, particle size, and UV–vis spectra of the polyurethane dispersions were investigated. The tensile properties of the cast films were determined. The modified dispersing procedure gave polyurethane dispersions with higher molecular weight and better tensile strength. As the molecular weight of the carboxylic polycaprolactonediol decreases, the content of the ionic groups increases, the particle size decreases accordingly. As the molecular weight of the carboxylic polycaprolactonediol used is 1000 g/mol or below, the polyurethanes dispersions become completely clear. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

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.     

Synthesis and properties of aqueous polyurethane dispersions: Influence of molecular weight of polyethylene glycol

Aqueous polyurethane dispersions (PUDs) have recently emerged as important alternatives to their solvent-based counterparts for various applications due to increasing health and environmental awareness. A series of aqueous polyurethane dispersions containing carboxylate anion as hydrophilic pendant groups were synthesized through step growth polymerization reaction using hexamethylene diisocyanate (HDI), 1,4-butanediol (1,4-BDO), dimethylol propionic acid (DMPA) and polyethylene glycol (PEG) of different molecular weight. Effect of PEG molecular weight was investigated on molecular structure, contact angle measurement, and physical and adhesive properties of PU emulsions. Fourier transform infrared spectroscopy (FT-IR) was used to check the completion of polymerization reaction. Contact angle measurement indicated that the hydrophilicity of polymer increases by increasing molecular weight of PEG with a corresponding decrease in contact angle. Results of T-peel test showed a decrease in peel strength by increasing molecular weight of PEG. Moreover, solid contents%, drying time and storage stability suggested fast drying properties and greater stability of aqueous PU dispersions.     

Aqueous dispersion of polyurethanes from H12MDI,PTAd/PPG,and DMPA: Particle size of dispersion and physical properties of emulsion cast films

Aqueous dispersions of ionic/nonionic polyurethane (PU) were prepared from hydrogenated diphenylemthane diisocyanate (H₁₂MDI), poly(tetramethylene adipate) glycol (PTAd), polypropylene glycol (PPG), monofunctional ethylene-propylene oxide ether, and dimethylol propionic acid (DMPA). The effects of DMPA, PTAd/PPG ratio, and the average molecular weight of PPG on the state of dispersion, mechanical, and viscoelastic properties of the emulsion cast films were determined using Authosizer, Instron, and Rheovibron.     

Fluorinated segmented polyurethane anionomers for water–oil repellent surface treatments of cellulosic substrates

Three model structures of linear segmented anionomeric polyurethanes based on perfluoropolyether dimethylol‐terminated oligomers, isophorone diisocyanate, and dimethylol propionic acid were synthesized and obtained in the form of aqueous dispersions. The structures differed from each other in the chemical nature of the chain extender (diol or diamine) and in the content of carboxylic acid. Dispersions and polymer films were characterized by dynamic light scattering, dynamic mechanical analysis, differential scanning calorimetry, and contact angle measurements. Diluted aqueous dispersions were also evaluated as protective sizing agents in paper treatment, both as bulk modifiers and as surface treatments. Paper sheets characterized by high water and oil repellence were obtained. The results showed that performance is mainly related to the ionic group content of the polymer and to its molecular architecture. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1364–1372, 2005     

Surfactant-free core–shell hybrid latexes from soybean oil-based waterborne polyurethanes and poly(styrene-butyl acrylate)

Novel surfactant-free core–shell hybrid latexes have been successfully synthesized by seeded emulsion polymerization of 10–60 wt% vinyl monomers (styrene and butyl acrylate) in the presence of a soybean oil-based waterborne polyurethane (PU) dispersion as seed particles. The soybean oil-based waterborne polyurethanes, synthesized by reacting isophorone diisocyanate with methoxylated soybean oil polyols and dimethylol propionic acid, form the latex shell, serve as a polymeric high molecular weight emulsifier, while the vinyl polymers form the core. The structures and thermal and mechanical properties of the PU dispersions and the resulting core–shell latexes have been characterized by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and measurement of the mechanical properties. The core–shell hybrid latex films show a significant increase in thermal stability and mechanical properties when compared with the pure polyurethane films, and exhibit a change in mechanical behavior from elastomeric polymers to tough and hard plastics, due to grafting and crosslinking in the hybrid latexes.     

Waterborne anionomeric polyurethane–ureas from functionalized fluoropolyethers

A family of anionomeric segmented polyurethane–ureas made from α‐ω dimethylol‐terminated perfluoropolyethers (M_n = 1000–2000), isophorone diisocyanate, dimethylol propionic acid, and ethylenediamine was obtained in form of stable aqueous dispersions. The dispersions were characterized by viscometry and dynamic laser light scattering. The main compositive parameters explored were the amount of COOH groups and the length of the fluorinated macromer. The new polyurethane–ureas were characterized by dynamic mechanical analysis obtaining information on modulus, thermal transition, and phase segregation. Surface properties and chemical resistance were estimated through measurements of static contact angles and spot tests with different solvents. Although surface hydrophobicity was not affected by composition, water‐sorption behavior was sensitive to the ionic character (COOH level) of the polymer. Diffusion and permeability coefficients of polymer films, having different carboxyl contents, were estimated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 136–144, 2004     

Effect of dicarboxylic acids on the performance properties of polyurethane dispersions

A series of low molecular weight linear polyester polyols were synthesized by using various diacids, neopentyl glycol, as a diol, and a trimethylol propane, as a branching monomer. Polyurethane dispersions were prepared primarily from isophorone diisocyanate, polyester polyol, and dimethylol propionic acid, as potential ionic center for water dispersibility, and were subsequently chain extended with ethylene diamine. The effect of polyester polyols based on variable diacids, on the physico‐chemical and thermal properties of polyurethane dispersions were evaluated by hardness, flexibility, impact resistance, solvent resistance, thermogravimetric analysis, and differential scanning calorimetry. Particle size was evaluated by particle size analyzer. It was observed that the number of alkylene groups present in the polyester polyol soft segment in addition to its molecular weight had a pronounced effect on the particle size, physico‐chemical, and thermal properties. With a proper selection of the soft segment, it is possible to fine‐tune properties of aqueous polyurethane dispersion coatings with respect to the final application. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

水性聚氨酯相对分子质量的影响因素及胶膜力学性能

采用异佛尔酮二异氰酸酯(IPDI)和聚醚二元醇(N-220)为主要原料,二羟甲基丙酸(DMPA)为亲水扩链剂,乙二胺(EDA)为后扩链剂,合成了一系列聚醚型聚氨酯(WPU)水分散体。考察了nNCO/nOH和中和度的变化对聚氨酯相对分子质量的影响以及聚氨酯相对分子质量与聚氨酯胶膜的力学性能和耐水性的关系。结果表明,随着nNCO/nOH的降低,聚氨酯的相对分子质量呈现先上升后下降的规律;随着中和度的增加,聚氨酯的相对分子质量增加;当nNCO/nOH为1.25时,水性聚氨酯相对分子质量最高,胶膜的力学性能和耐水性最好。     

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.     

乙二胺后扩链TDI型聚氨酯水分散体的过程

以甲苯二异氰酸酯（TDI）、聚氧化丙烯二醇和二羟甲基丙酸等为主要原料制备了聚氨酯水分散体,研究了水、扩链温度、原料的-NCO/-OH摩尔比及扩链比对乙二胺（EDA）后扩链TDI型聚氨酯水分散体过程的影响。FT-IR测试表明,分散体中的H₂O可通过与聚氨酯中残留异氰酸酯基团（-NCO）的竞争反应影响EDA的后扩链过程。分子量及粒径与zeta电位测试表明,H₂O扩链导致分散体失稳;低扩链比时,H₂O对EDA的后扩链过程影响明显,但高扩链比时,后扩链聚氨酯的分子量降低;扩链温度升高,经EDA后扩链聚氨酯的分子量降低,而分散体粒径增大。当原料的-NCO/-OH摩尔比为1.20、扩链温度为30℃、扩链比为60%时,可有效降低H₂O对EDA后扩链聚氨酯过程的影响。     

不同相对分子质量PEG制备DDI型水性聚氨酯及其织物整理应用

以二聚脂肪酸二异氰酸酯( DDI)、不同相对分子质量的聚乙二醇(PEG)、二羟甲基丙酸( DMPA)为主要原料,采用丁酮法制备预聚体,然后在乳化剂存在下制成水性聚氨酯(WPU).研究了PEG相对分子质量对WPU的影响以及其应用到织物整理上的效果.结果表明,当PEG相对分子质量为1000和1500时,DDI型水性聚氨酯整...     

Effect of ionic content,solid content,degree of neutralization,and chain extension on aqueous polyurethane dispersions prepared by prepolymer method

There are many variables in the preparation of aqueous polyurethane (PU) dispersions. Carboxylic acid content, solid content, degree of pre/postneutralization of the carboxylic acids, and chain extension all impact dispersion particle size, viscosity, pH, molecular weights, and glass transition temperature. This study evaluated the impact of these variables on a given PU dispersion formulation prepared from isophorone diisocyanate, an aliphatic polyester polyol, dimethylol propionic acid, and hexamethylene diamine with triethyl amine as the neutralizing base and N‐methyl pyrrolidone as the cosolvent. Changes in carboxylic acid content, degree of preneutralization, and chain extension were found to have the expected impacts on dispersions properties. Increased ionic content in the dispersion step led to lower particle size and higher viscosity, increased chain extension with its concurrent increase in molecular improved subsequent film properties. Surprising results were obtained by varying the amount of postneutralization and from increased solids content at the time of dispersion. Unexpectedly, both of these variations led to much higher dispersion viscosities and particle size in solution. To have these changes take place, it is theorized that there is a major change in solution morphology caused by these modifications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2514–2520, 2005     

Effects of TDI and FA‐703 on physico‐mechanical properties of polyurethane dispersion

A series of water dispersion polyurethanes dispersions (PUDs) were prepared by polyaddition reaction using isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), poly(oxytetramethylene) glycol (PTMG), dimethylol propionic acid (DMPA), and triol (trade name FA‐703). Various formulations were designed to investigate the effects of process variables such as TDI and FA‐703 on the physico‐mechanical properties of PUD. IR spectroscopy was used to check the end of polymerization reaction and characterization of polymer. Evolution of the particle size distribution, contact angle, T_g, molecular weight, viscosity, and mechanical properties of the emulsion‐cast films were significantly affected by variable content of TDI and FA‐703. Average particle size of the prepared polyurethane emulsions and contact angle decrease with increase of content of FA‐703 and TDI. Molecular weight, T_g, tensile strength, tear strength, hardness, viscosity and elongation at break increase with increase of content of FA‐703 and TDI. The increase of molecular weight, tensile strength, tear strength and elongation at break properties are interpreted in terms of increasing hard segments, chain flexibility, and phase separation in high content of FA‐703 and TDI‐based polyurethane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Influence of Diisocyanate Structure on the Synthesis and Properties of Ionic Polyurethane Dispersions

A number of aqueous polyurethane dispersions based on polytetramethylene glycol (PTMG), 1,4-butanediol (1,4-BDO), dimethylol propionic acid (DMPA) and diisocyanates of differing structures such as toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (H₁₂MDI) were prepared. IR Spectroscopy was used to check the end of polymerization reaction and also the polymer characterization. The effects of diisocyanate structure on the particle size, contact angle, mechanical and thermal properties of the emulsion-cast films were studied. Average particle size of prepared polyurethane emulsions change by different diisocyanate based polyurethane. TDI based PU shows higher average particle size and contact angle than the others. Tensile strength, hardness, and elongation at break were higher in the case of MDI based polyurethane. Thermal property and thermal stability is also affected by variation of diisocyanate molecular structure.     

The influence of the degree of neutralization,the ionic moiety,and the counterion on water‐dispersible polyurethanes

A number of polyurethane anionomers based on isophorone diisocyanate, polytetrahydrofuran, and cyclohexane dimethanol were prepared as aqueous dispersions. The dispersions were stabilized by the use of an internal emulsifier. The principal ionic moiety used was dimethylol propanoic acid, but dimethylol butanoic acid and an experimental suphonate diol sodium salt were also used. The consequence of the neutralization step, the degree of neutralization, the type of ionic component, and the type of counterion were investigated for their effect on the mechanical and colloidal properties of the polyurethanes. Dynamic mechanical thermal analysis, tensiometry, solvent spot testing, and swelling studies were used for the characterization of the materials. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 556–566, 1999     

Highly branched and tartaric acid‐based water‐borne resins

In this study, water‐borne polyurethane resins were produced using poly(propylene‐ethylene) copolymer triol, toluene diisocyanate, and hydrophilic monomers, dimethylol propionic acid and tartaric acid. The hydrophilic monomers were used separately. In either case, the ratio of isocyanate functional groups to the sum of hydroxyl groups of polyol and hydrophilic monomer was kept constant. The increase in the amount of hydrophilic monomer increased the hardness of resins when used as varnish. Tartaric acid resulted in higher hardness than dimethylol propionic acid. The dispersions made by using tartaric acid had much larger particle sizes than those of dimethylol propionic acid. In another set of experiments, the samples carrying the optimum properties from the two sets were mixed with methylol urea that served as crosslinker in the baking step. The physical and mechanical properties were determined by changing the weight percentages of the two types of samples in the mixture, and by changing the methylol urea percentage of the mixture which exhibited the maximum hardness. All samples showed superior impact resistance, adhesion, and flexibility. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 604–612, 2001