Aqueous Dispersion of Polyurethane Anionomer from Aliphatic Diisocyanates and Poly(Hexamethylene Carbonate) Diol

Abstract

Water dispersible polyurethanes (PUs) were prepared from poly(hexamethylene carbonate) (PHC) diol, isophorone diisocyanates (IPDI), hexamethylene diisocyanate (HDI), and dimethylolpropionic acid (DMPA) as latent anionic sites. After neutralization of the carboxyl group from the DMPA unit with triethylamine (TEA), the PU anionomers were dispersed by adding water, following by crosslinking using triethylenetetramine (TETA). The particle size of the dispersion decreased with the content of DMPA and increased with HDI in the HDI-IPDI system, and it exhibited a minimum when the number-average molecular weight (M _n) of the prepolymer was 3000 and 4500, respectively. PUs with a higher content of hard segments from DMPA or TETA, or with a higher content of IPDI rather than HDI, had higher tensile moduli and storage moduli at room temperature. Ultimate tensile properties increased with an increase of the prepolymer molecular weight and the DMPA and HDI content.     

Structure-property relationship of polyurethane ionomer

Polyurethane (PU) ionomers were prepared using various types of polyol (PTAd, PCL, PTMG, and PPG) and isocyanate (MDI, HDI, and IPDI), together with different extender (DMPA) contents, degree of neutralization, and number average molecular weight (M _n) of polyol. Modulus (E), strength (_b), and glass transition temperature (T _g) significantly increased with the increased amount of extender and extender neutralization. Among three of the iocyanate used, PU from MDI gave the highest modulus, strength, andT _g. With regard to theM _n of PTAd (600, 1000, 2000), PU from PTAd 600M _n gave the highest modulus, strength, andT _g, due probably to the highest hard segment content and phase mixing. On the other hand, PU from PTAd 2000M _n gave significantly improved strength over PTAd 1000M _n, and the highest elongation. The results were interpreted in terms of soft-segment crystallization, and soft-hard phase separation, which was concluded from the lowered softT _g.     

Semibatch emulsion polymerization of methyl methacrylate using different polyurethane particles

Aqueous acrylic‐polyurethane (AC–PU) hybrid emulsions were prepared by semibatch emulsion polymerization of methyl methacrylate (MMA) in the presence of four polyurethane (PU) dispersions. The PU dispersions were synthesized with isophorone diisocyanate (IPDI), 1000 and 2000 molecular weight (MW) poly(neopentyl) adipate, 1000 MW polytetramethyleneetherglycol, butanediol (BD), and dimethylol propionic acid (DMPA). MMA was added in the monomer emulsion feed. We studied the effect of the use of different PU seed particles on the rate of polymerization, the particle size and distribution, the number of particles, and the average number of radicals per particle. The PU rigidity was controlled by varying the polyol chemical structure, the polyol MW (M_n), and by adding BD. The monomer feed rate was varied to study its influence on the process. It was observed that the PU particles that had been prepared with a higher MW polyol swelled better with MMA before the monomer‐starved conditions occurred. There seemed to be no significant discrepancies between the series with different PU seeds in the monomer‐starved conditions. The overall conversion depended on the monomer addition rate, and the polymerization rate acquired a constant value that was comparable to the value of the monomer addition rate. The instantaneous conversion increased slightly. The average particle size increased, and the total particle number in the reactor was constant and similar to the number of PU particles in the initial charge. The average number of radicals per particle increased. The differences between the system with a constant particle number and average number of radicals per particle and the system with a fixed radical concentration are discussed. The semibatch emulsion polymerization of MMA in the presence of PU particles studied was better compared to the system with a fixed radical concentration. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 844–858, 2005     

水性聚氨酯胶粘剂结构与性能的研究

以聚醚烽异氟尔酮二异氰酸酯为主要原料,以二羟甲基酸为亲水单体制备了一组不同配方组成的聚氨酯乳胶粘剂。通过粘度测定、粒度分析、力度性能的测试以及DSC分析,研究了新水剂含量、软链段的类型和加料方法对乳液及其胶膜性能的影响。结果表明：二羟甲基丙酸含量在3％－8％之间可获得比较稳定的乳液,并且两步法较一步法制得的乳液分散性好,但胶膜力学性能方面,一步法较好。     

氨基硅油扩链改性水性聚氨酯的研究

通过将由甲苯二异氰酸酯与聚四氢呋喃,二羟甲基丙酸反应制得的聚氨酯预聚体在低浓度氨基硅油的水乳液中扩链,合成了一种硅氧烷改性的聚氨酯水乳液,并用傅立叶红外光谱,ＥＳＣＡ能谱,接触角仪,电子拉力试验机,吸水率测定及乳液稳定性测试对其进行研究。     

水性聚氨酯硬段含量对其氢键相互作用及性能的影响

异佛尔酮二异氰酸酯（IPDI）、二羟甲基丙酸(DMPA)作为硬段,合成了水性聚氨酯。 研究了硬段含量（质量分数）对乳液稳定性、膜耐热和力学性能等的影响。 当硬段质量分数低于26%时,乳液贮存稳定性较差。 随着硬段含量增加,聚氨酯膜拉伸强度迅速增加,断裂伸长率略有降低;红外光谱显示,自由的N-H伸缩振动峰强度减弱,氢键化N-H的振动峰强度增加;同时C=O伸缩振动峰整体向低波数方向移动,C=O伸缩振动峰峰形有明显的变化;DSC测试在50～125 ℃出现明显的氢键解离现象,吸热峰增强,证实了氢键作用力随着硬段含量的增加逐渐增强。 TG测试表明,水性聚氨酯硬段和软段分步解离,随着硬段含量的增加,硬段分解温度降低,水性聚氨酯耐热性能下降。     

Effects of altered reaction conditions on the synthesis of polyurethane-poly(2,2,2-trifluoroethyl methacrylate) triblock copolymer aqueous dispersion

Polyurethane-poly(2,2,2-trifluoroethyl methacrylate) (PU-PTFEMA) triblock copolymer aqueous dispersions were synthesized by three-step polymerization. In the first step, polyurethane prepolymers (PU) based on 2,4-toluene diisocyanate (TDI), polyether binary alcohol (N₂₂₀), α,α-dimethylol propionic acid (DMPA), hydroxypropyl acrylic acid (HPA), and butanediol (BDO) were prepared with butanediol as the chain extender and methylethylketon as solvent. The next step involved neutralization and dispersion in water, where prepolymers were neutralised by the addition of triethylamine (TEA). The last step was the seeded emulsion polymerization, where PU emulsion was used as seed, kalium persulfate (KPS) as initiator and 2,2,2-trifluoroethyl methacrylate (TFEMA) as comonomer. Factors influencing the synthesis of PU-PTFEMA copolymer aqueous dispersion were studied. Experimental data indicate that factors influencing the synthesis of PU-PTFEMA copolymer aqueous dispersion mainly involve reaction temperature, reaction time, the concentration of initiator, DMPA content, TFEMA content. Rotational viscometer and dynamic light scattering (DLS) were used to characterize the properties of copolymer aqueous dispersion.     

Control synthesis of isocyanate and alkoxy-silane terminated macromers

The kinetics of the reactions in bulk of 4,4′-dicyclohexyl methane diisocyanate (H₁₂ MDI) and 5-isocyanato-1,3,3-trimethylcyclohexylmethyl isocyanate or isophorone diisocyanate (IPDI) with benzylic alcohol (BZA) and α-hydroxy-ω-methyl ether-terminated polyethylene oxide PEO (M?_w = 350) were studied by size exclusion chromatography (SEC) and ¹³C nuclear magnetic resonance (¹³C-NMR). The substitution effect is exhibited in the case of H₁₂ MDI reactivity. The kinetic constants were calculated by a numerical method. The second-order kinetic mechanism was shown to be valid. In the IPDI case, the cycloaliphatic isocyanate group is shown to be more reactive than the aliphatic group in our conditions, without catalysis, in agreement with previous results from the literature, in our obtained by ¹H-and ¹³C-NMR without any catalyst. The reactivity ratio is found to be on the order of 3. This difference in reactivity of the two isocyanate groups is used for the control synthesis of isocyanate and alkoxy-silane-terminated macromers.     

Synthesis and characterization of polyurethane–urea nanoparticles containing methylenedi‐p‐phenyl diisocyanate and isophorone diisocyanate

Water‐based polyurethane–urea (WPUU) nanoparticles containing 4,4′‐methylenedi‐p‐phenyl diisocyanate (MDI) and isophorone diisocyanate (IPDI) were synthesized by a stepwise prepolymer mixing process, that is, the consecutive formation of hydroxyl‐terminated and isocyanate‐terminated polyurethane prepolymers. The reaction behavior, chemical structure, and consequent morphology of the polyurethane prepolymers and WPUU were investigated with Fourier transform infrared (FTIR), gel permeation chromatography, and NMR techniques with MDI concentrations ranging from 0 (pure IPDI) to 50% with respect to the total moles of isocyanate. Wide‐angle X‐ray diffraction and differential scanning calorimetry patterns showed that the crystallinity of WPUU, which mostly originated from crystallizable poly(tetramethylene adipate) polyol, was significantly affected by the MDI content. Both the crystallinity and melting temperature of WPUU decreased as the MDI content increased. Deconvoluted relative peak areas of the carbonyl region in the FTIR spectrum revealed that the effect of hydrogen bonding among the hard segments became favorable as the MDI content increased, whereas the hydrogen bonding of the soft segments significantly decreased. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4353–4369, 2004     

氨基硅油扩链改性水性聚氨酯的合成及性能研究

采用甲苯二异氰酸酯(TDI)、聚氧化丙烯二醇(PPG)、2,2-二羟甲基丙酸(DMPA)为原料,先制备成聚氨酯预聚体,再通过在乳化过程中以侧链氨基硅油(AEAPS)或直链氨基硅油(ATPS)扩链制得了一系列水性聚氨酯乳液,并对涂膜的红外光谱、耐水性、力学性能和表面疏水性等进行了研究。结果表明,通过氨基硅油改性的聚氨酯涂膜,在保持力学性能基本不变的情况下,其耐水性、表面疏水性等性能都有明显提高。其中,侧链氨基硅油(AEAPS)比直链氨基硅油(ATPS)具有更好的改性效果。     

软段对水性聚氨酯结构与性能的影响

以低聚物多元醇、异氟尔酮二异氰酸酯(IPDI)、亲水单体二羟甲基丙酸(DMPA),乙二胺为主要原料,制备了一组不同组成的聚氨酯乳液。通过粘度测定、粒度分析、力学性能和耐水性能测试、原子力显微镜(AFM)分析,研究了软段类型、软段分子量对乳液及其胶膜性能的影响。结果表明,分子结构规整、易结晶的软段合成的聚氨酯树脂力学性能和耐水性能都较好,对聚己二酸酯而言,分子量减小,其合成的水性聚氨酯拉伸强度提高,耐水性能却有很大程度的下降。     

Basic structure–property behavior of polyurethane cationomers

Polyurethane (PU) cationomers were synthesized from polytetramethylene adipate glycol (PTAd), isophorone diisocyanate (IPDI), and N-methyl diethanolamine (MDEA) according to a prepolymer mixing process. Basic structure-property behavior of the emulsion (obtained by adding water to the ionomer solution) and emulsion cast film was studied with regard to the molecular weight (M_n) of PTAd, MDEA content, degree of neutralization, and extender functionality. Particle size decreased asymptotically with increasing M_n of PTAd due to the increased chain flexibility, and with the degree of neutralization due to the increased hydrophilicity of the PU. Emulsion viscosity generally showed the opposite tendency with particle size dependence. The major transition temperature, corresponding to the glass transition (T_g) of phase mixed PU or hard segment-rich phase of the PU monotonically increased with MDEA content, degree of neutralization, and with increasing extender functionality. However, with increasing M_n of PTAd, T_g first decreased (M_n = 1000) and then increased (M_n = 1500, 2000), due respectively to the increased hard fraction of phase mixed PU, and soft segment crystallization. Tensile strength increased and elongation at break decreased with MDEA content, degree of neutralization, and extender functionality. © 1994 John Wiley & Sons, Inc.     

脂肪族水性聚氨酯的力学性能研究

考察了软段的种类、分子量大小、混合软段的组成对产物力学性能的影响作用。同时还研究了二羟甲基丙酸(DMPA)用量以及中和剂的影响作用．实验结果表明。软段结构对脂肪族水性聚氨酯成膜的力学性能影响很大，聚酯型产物具有较高的模量和拉伸强度。聚醚型产物则具有较高的伸长率．混合软段对产物力学性能的影响较为复杂，随着软段中聚醚含量的升高，产物的硬度和模量均大幅度下降，但拉伸强度和伸长率的变化并不是一个线性关系．产物的模量随软段分子量的提高而降低，但伸长率和拉伸强度却有所提高．当DMPA用量较高时。产物的模量和拉伸强度均较高：当DMPA用量较低时，产物则具有较高的伸长率．中和剂的种类对产物力学性能的影响明显，当以NaOH为中和剂时，产物具有较高的硬度、模量、拉伸强度：以三乙胺为中和剂时，产物具有较高的伸长率．     

硅氧烷改性水性聚氨酯的制备及性能

A series of novel aqueous emulsion of siloxane modified polyurethane (PU(PE-PSI)) were synthesized based on poly(propylene glycol) (PPG), polyether-grafted polysiloxane (PE PSI), 2,4-tolylene diisocyanate (TDI), dimethylol propionic acid (DMPA) and 1,4 butanediol (BDO) through a direct water emulsification of triethylamine (TEA). The aqueous emulsion was transparent and had a good stability. Fourier transform infrared spectroscopy (FTIR) was used to identify the structure of PU (PE PSI), indicating that the polysiloxane segment had been incorporated with polyurethane chain. Investigation of Electron Spectroscopy for Chemical Analysis (ESCA) and the water contact angle demonstrated that the siloxane migrated to the surface of film. The results also showed that PU(PE-PSI) was still a very good elastomer. With increasing the content of PE PSI, the resistance to water improved and tensile strength increased, while the ultimate elongation decreased slightly for the PU(PE-PSI) film.     

Study of elastomeric polyurethane nanocomposites prepared from grafted organic–montmorillonite

4,4′-Diphenylmethane diisocyanate (MDI) was grafted on to organic–montmorillonite (OMMT) by reaction between hydroxyl groups (−OH) on surface of the montmorillonite and the isocyanate groups (−NCO) of MDI, thus forming grafted organic–montmorillonite (MOMMT). Intercalated nanocomposites based on polyurethane (PU) and MOMMT were prepared by solution intercalation technology. The interface interaction of PU/MOMMT nanocomposites was better than that of PU/MMT composites. The tensile strength, elongation at break, and tear strength of the PU/MOMMT nanocomposites increased for MOMMT content up to 5% w/w, and then decreased with further increase in MOMMT content. At the same filler content, the tensile strength and tear strength of PU/MOMMT nanocomposites were higher than those of PU/OMMT nanocomposites, whereas the elongations at break of PU/MOMMT nanocomposites were smaller than those of PU/OMMT nanocomposites. The initial temperatures of weight loss of PU/MOMMT nanocomposites were lower than for PU/MMT composites in the first step of thermal degradation, whereas in the second step initial temperatures of weight loss were higher for PU/MOMMT nanocomposites.     

Preparation and properties of PU/MCMMT nanocomposites

The cetyltrimethyl ammonium bromide (CTAB) was used as a swelling agent to be intercalated into the galleries of the montmorillonite (MMT) platelets to get the organic MMT (CMMT). Then 4,4′‐diphenylmethane diisocyanate (MDI) were grafted on CMMT by the reaction between hydroxyls in organic MMT platelets and MDI to synthesize the MDI modified CMMT (MCMMT). Polyurethane (PU)/MCMMT composites were prepared by situ polymerization. The MCMMT platelets dispersed in a PU matrix in nanometer scale. The dispersion and intercalation degree of the MCMMT platelets decreased with increase in the content of MCMMT. Under the same content of fillers, the tensile strength and tear strength of PU/MCMMT nanocomposites were higher than those of PU/organic MMT nanocomposites. The reinforcing effect of the MCMMT platelets to the PU was better than that of the organic MMT platelets. With increase in the content of MCMMT, the tensile strength and tear strength of the PU/MCMMT nanocomposites were increased, while the extent of the increase slowed down. Compared with those of PU, the thermal stability of PU/MCMMT nanocomposites was increased. Copyright © 2009 John Wiley & Sons, Ltd.     

UV-curable poly(ethylene glycol)–based polyurethane acrylate hydrogel

Poly(ethylene glycol) (PEG) with molecular weight (M_n) of 1000, 2000, 3000, and 4000 g/mol, four types of diisocyanate [hexamethylene diisocyanate (HDI), 4,4′-dicyclohexylmethane diisocyanate (H₁₂MDI), isophorone diisocyanate (IPDI), and toluene diisocyanate (TDI)], two types of comonomers [acrylamide (AAm) and acrylic acid (AAc)] that comprised up to 60% of the total solid were used to prepare UV-curable PEG–based polyurethane (PU) acrylate hydrogel. The gels were evaluated in terms of mechanical properties, water content as a function of immersion time and pH, and X-ray diffraction profiles of dry and swollen films. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2703–2709, 1999     

Biodegradable Polyurethanes from Plant Components

Abstract

Polyurethane (PU) sheets and foams having plant components in their network were prepared by using the following procedure. Polyethylene glycol (PEG) was mixed with one of the following; molasses, lignin, woodmeal, or coffee grounds. The mixture obtained was reacted with diphenylmethane diisocyanate (MDI) at room temperature, and precured PUs were prepared. The precured PUs were heat-pressed and PU sheets were obtained. In order to make PU foam, the above mixture was reacted with MDI after the addition of plasticizer, surfactant (silicone oil), catalyst (di-n-butyltin dilaurate), and droplets of water under vigorous stirring. The glass transition temperature, tensile and compression strengths, and Young's modulus of the PU sheets and foams increased with an increasing amount of plant components. This suggests that saccharide and lignin residues act as hard segments in PUs. It was found that the PUs obtained were biodegradable in soil. The rate of biodegradation of the PUs derived from molasses and coffee grounds was between that of cryptomeria (Cryptomeria japonica) and beech (Fagus sieboldi).     

Structure-property relationships in polycaprolactone-polyurethanes

The structure-property relationships of polycaprolactone-based segmented polyurethanes were studied using differential scanning calorimetry (DSC), small-angle x-ray scattering (SAXS), wide-angle x-ray diffraction (WAXD), dynamic mechanical, and stress-strain testing. The materials studied varied in hard-segment type [4,4′-diphenylmethane diisocyanate/butanediol (MDI/BD) or 4,4′-dicyclohexyl methane diisocyanate/butanediol (H₁₂MDI/BD)], soft-segment molecular weight (830 or 2000 MW polycaprolactone), hard-segment content (23–77% by weight), and thermal history. The materials with aromatic (MDI/BD) hard segments had semicrystalline hard-segment domains, while the materials with aliphatic (H₁₂MDI/BD) hard segment had mostly amorphous domains. Materials with the shorter polycaprolactone soft segment (830 MW) exhibited thermal and mechanical behavior which indicated a considerable degree of hard- and soft-segment compatibility. The materials which contained a 2000-MW polycaprolactone soft segment exhibited better-defined microphase separation. SAXS was used to characterize the microphase structure of each system. The effects of hard-segment content and soft-segment molecular weight were similar for the aromatic (MDI) and aliphatic (H₁₂MDI) hard-segment-based block copolymers. Changing the hard segment from aromatic to aliphatic gave materials with larger interfacial area and slightly higher tensile strength. A range of morphologies between isolated hard domains in a rubbery matrix and isolated rubbery domains in a hard matrix was observed.     

Structural, thermal and morphological properties of aqueous hybrid emulsion of silylated poly (urethane)/organic modified montmorillonite nanocomposites based on a new silicone and imide ring containing vinylic macromonomer

A new silicone and imide ring containing vinylic macromonomer, N-trimethylsiloxyethyltrimellitilimidomethacrylate (TMSETMIM), has been synthesized for the formulation of waterborne polyurethane (PU). A vinyl group containing silicone, the (3-methacryloyloxypropyl) trimethoxysilane (MPTMS) was used for comparison of the effects of silicone type with TMSETMIM on the PU. Then, a series of new siliconized PU hybrid nanocomposites, were successfully synthesized by the emulsion polymerization in the presence of organic modified montmorillonite (OMMT) and an aqueous PU dispersion using ammonium peroxodisulfate (APS) as an initiator. The PU dispersion was synthesized by a polyaddition reaction of hexamethylene diisocyanate (HMDI), on polypropylene glycol (PPG-1000) and dimethylol propionic acid (DMPA) as a chain extender. The obtained NCO chain ends reacted with water (which acts as a further chain extender producing some urea bonds). The structural elucidation of monomer was carried out by FTIR, ¹H-NMR, and ¹³C-NMR spectroscopic techniques. The copolymers were also characterized by using FTIR. Thermal properties of the copolymers were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphologies of the copolymers were characterized with scanning electron microscopy (SEM) and transition electron microscopy (TEM) and then the effects of silicone concentrations on the water absorption ratio was examined. The formed film from the hybrid emulsion containing TMSETMIM could provide obviously higher water-resistance property in comparison with MPTMS. Also, the heat stability increases while the T _g decreased.