Miscibility and properties of blend materials from waterborne polyurethane and carboxymethyl konjac glucomannan

We prepared composite materials by blending waterborne polyurethane (WPU) and carboxymethyl konjac glucomannan (CMKGM) with CMKGM content from 15 to 80 wt % in an aqueous system. The structures and properties of the blend materials were characterized by FTIR, dynamic mechanical analysis, ultraviolet spectroscopy, scanning electron microscopy, wide‐angle X‐ray diffraction, thermogravimetric analysis, and tensile testing. The results indicated that the blend sheet with 80 wt % CMKGM exhibited good miscibility and higher tensile strength (89.1 MPa) than that of both WPU (3.2 MPa) and CMKGM (56.4 MPa) sheets. Moreover, with an increase of CMKGM content, the tensile strength, Young's modulus, and thermal stability increased significantly, attributed to intermolecular hydrogen bonding between CMKGM and WPU. Based on the experimental results, the blend materials have good, or a certain degree of, miscibility over the whole range of composition ratio of WPU to CMKGM. In addition, the blend materials exhibited organic solvent resistance. This work not only provided a simple method to prepare environmentally friendly materials, but also expanded the application of CMKGM. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 77–83, 2004     

Effects of NCO/OH molar ratio on miscibility and properties of semiinterpenetrating polymer networks from polyurethane and benzyl konjac glucomannan

Semi‐interpenetrating polymer network (semi‐IPN) films with different NCO/OH molar ratios of the urethane prepolymer, coded as UB, were prepared from polyurethane (PU) and benzyl konjac glucomannan (B‐KGM) by a casting method. The effect of the NCO/OH molar ratio of the urethane prepolymer on the miscibility and properties of the UB films was investigated using Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical thermal analysis, thermogravimetric analysis, and swelling and tensile tests. The results indicated that, with an increase of the NCO/OH ratio, the crosslink density of the UB films increased, resulting in improved miscibility between PU and B‐KGM and a relatively high light transmittance of the UB films. However, the thermal stability of the UB films decreased with increase of the NCO/OH ratio of the urethane prepolymer, due to the depolymerization of the urethane bonds of the PU networks. When the NCO/OH ratio increased from 2 to 4, the tensile strength of the UB films increased from 15 to 27 MPa, while the breaking elongation decreased from 72 to 16%, resulting from the chemical and physical crosslinks, namely, the enhancement of the covalent bonds and hydrogen‐bonding networks. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1304–1310, 2003     

The influence of the NCO/OH ratio and the 1,6-hexanediol/ dimethylol propionic acid molar ratio on the properties of waterborne polyurethane dispersions based on 1,5-pentamethylene diisocyanate

1,5-Pentamethylene diisocyanate, a novel aliphatic diisocyanate formed from bio-based 1,5-pentamethylenediamine, has been used as a hard segmented material to synthesize polyurethane. In this study, several waterborne polyurethane (WPU) dispersions have been successfully prepared by a prepolymer process from 1,5-pentamethylene diisocyanate poly(polyether) with different NCO/OH ratios and 1,6-hexanediol (HDO)/dimethylol propionic acid (DMPA) molar ratios. The Fourier transfonn infrared (FTIR) spectra, thermogravimetric analysis, differential scanning calorimetry, X-ray diffiraction, and a mechanical tensile test were used to investigate the structures, thermal stability, phase separation, crystallinity, mechanical properties, and adhesive performance of the WPU dispersions. The FTIR results indicate that the degree of hydrogen bonding and the numbers of urea groups increase as the NCO/OH ratio and HDO/DMPA molar ratio increase. Furthermore, the phase separation increases and the thermal stability decreases as the NCO/OH ratio increases or the HDO/DMPA molar ratio decreases. Finally, WPU3.0-2.4 (NCO/OH = 3, HDO/DMPA = 2.4) exhibits a maximum tensile strength and shear strength, pointing to its possible use as an adhesive. These results could provide a very valuable reference for industrial applications of WPU.     

Properties and paper sizing application of waterborne polyurethane emulsions synthesized with isophorone diisocyanate

In this work, a two-step synthesis methodology has been used to synthesize a series of waterborne polyurethane (WPU) emulsions with isophorone diisocyanate (IPDI), poly-caprolactone diol (PCL) and dimethylol propionic acid (DMPA) as monomers and ethylenediamine (EDA) as the chain extender, respectively. The influences of the NCO/OH molar ratio, DMPA content, chemicals-adding sequence, and acetone content on the physical properties of the resultant emulsions have been investigated in detail. The results show that the emulsion viscosity increases with an increase in the NCO/OH molar ratio or DMPA content whereas it declines sharply as the acetone amount increases. The emulsion particle size is seen to increase with the NCO/OH molar ratio but it decreases as the DMPA content increases. The chemicals-adding sequence is observed to strongly affect the particle size and viscosity of the resultant emulsions. For cast films, with an increase in the NCO/OH molar ratio, the elongation monotonically decreases while the tensile strength is seen to increase at first and then deceases. The film water absorption capacity is found to go up as the DMPA content increases. Furthermore, after sized with the emulsions, the paper water resistance is markedly improved and the 30s Cobb value is seen to decrease by 63% as compared to the unsized counterpart. The paper folding resistance and the tensile index are also improved to certain extents. For producing well-performed WPU emulsions for sizing paper sheets, an NCO/OH molar ratio of 1.6–1.8 and a DMPA content of 6.0–7.0 wt.% are preferably chosen.     

水性聚氨酯电导率与聚沉值的研究

研究了软（硬）段含羧基的水性阴离子纳米聚氨酯体系的n(NCO)/n(OH)比值，COOH的质量分类，反离子各类，合成方法与电导率关系及产生的原因；探讨了该体系的n(NCO)/n(OH)值，COOH的质量分数，合成方法与临界聚沉值（Cc.c)的关系和规律。并分析，比较了软（硬）段含羧基的水性阴离子聚氨酯体系电导率与Cc.c二者关系，得出了随COOH的质量分数升高，二者变化相同，随n(NCO)/n(OH)比值升高,二者变化相反的结论。     

聚碳酸酯型水性聚氨酯乳液的制备与性能

以聚碳酸酯二元醇和异佛尔酮二异氰酸酯为主要原料,采用预聚法合成了聚碳酸酯型水性聚氨酯( WPU) ,用傅里叶变换红外光谱表征了WPU,考察了不同NCO/OH( 摩尔比) 对WPU 乳液粒径及薄膜的耐水性、拉伸性能的影响,并研究了WPU 的热稳定性。结果表明,随着NCO/OH 值的增大,WPU乳液的粒径增大,稳定性降低,薄膜的耐水性和拉伸强度提高,扯断伸长率降低; WPU 薄膜的热分解速率较快,硬段的热分解温度为193 ℃,最大失重温度为287 ℃; 软段的热分解温度为321 ℃,最大失重温度为364 ℃左右。     

蓖麻油改性聚醚型水性聚氨酯乳液的性能

以聚醚、甲苯二异氰酸酯(TDI)、一缩二乙二醇、蓖麻油为主要原料,二羟甲基丙酸(DMPA)为亲水扩链剂,三乙胺为中和剂制备了稳定的阴离子水性聚氨酯乳液(WPU),研究了NCO/OH摩尔比、DMPA及蓖麻油的加入量对WPU的耐水性、稳定性和力学性能的影响,结果表明:改性后的乳液具有较好的稳定性,适量的蓖麻油可提高胶膜的拉伸强度及耐水性。当聚醚与蓖麻油质量比为7︰3、DMPA为5%、NCO与OH摩尔比为1.3时,WPU综合性能最好。     

高固含量水性聚氨酯分散体的合成

引　言水性聚氨酯是水溶型、水分散型和水乳化型聚氨酯的统称 .水性聚氨酯与溶剂型相比较 ,具有生产、运输和使用安全 ,不污染环境的优点 ,在涂料、黏合剂和皮革涂饰剂等方面的应用备受重视[1] ,成为近 10年来全世界的研究热点 .水性聚氨酯的弱点是其制成的涂料和涂饰剂的机械性能、耐水性不如溶剂型聚氨酯 .克服这些弱点 ,是近年来各国研究者努力的方向[2 ] .在改善水性聚氨酯性能方面有大量研究报道 ,诸如降低亲水基团含量 ,增大乳液粒径 ,采用强力机械分散增加乳液贮存稳定性 ,改善乳液对涂膜基材表面的润湿性、黏附力等等[3] .但很少见…     

Preparation and properties of castor oil‐based polyurethane/α‐zirconium phosphate composite films

Novel castor oil‐based polyurethane/α‐zirconium phosphate (PU/α‐ZrP) composite films with different α‐ZrP loading (0–1.6 wt %) and different NCO/OH molar ratios were synthesized by a solution casting method. The characteristic properties of the PU/α‐ZrP composite films were examined by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile testing. The results from Fourier transform infrared spectroscopy indicated that strong intermolecular hydrogen bonding formed between α‐ZrP and PU, XRD and SEM results revealed that the α‐ZrP particles were uniformly distributed in the PU matrix at low loading, and obvious aggregation existed at high loading. Because of hydrogen bonding interactions, the maximum values of tensile strength were obtained with 0.6 wt % α‐ZrP loading and 1.5 of NCO/OH molar ratio in the matrix. Evidence proved that the induced α‐ZrP used as a new filler material can affect considerably the mechanical and thermal properties of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The chain extender content and NCO/OH ratio flexibly tune the properties of natural rubber‐based waterborne polyurethanes

The effects of chain extender content (ethylene diamine, EDA) and NCO/OH ratio on the properties of natural rubber‐based waterborne polyurethanes (WPUs) were investigated experimentally. The particle size of WPU increased significantly with the NCO/OH ratio, in the presence of the EDA chain extender, while it was unaffected by the EDA content. The water uptake of WPU film increased with the EDA content, while the swelling in various solvents decreased. In a thermal analysis, the second decomposition stage of a WPU film increased with the EDA content and with the NCO/OH ratio that also positively affected the dynamic mechanical and mechanical properties. These factors in WPU films had no the effect on the T_g. The stress–strain curves clearly showed the change in WPU films from soft elastomeric materials to ductile and hard plastics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42505.     

Properties of crosslinked casein/waterborne polyurethane composites

Waterborne polyurethane (WPU) and casein (1 : 1 by weight) were blended at 90°C for 30 min, and then were crosslinked by adding 1–10 wt % ethanedial to prepare a series of sheets. Their structure and properties were characterized by using infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, dynamic mechanical analysis, and tensile testing. The results indicated that crosslinked blend sheets exhibited a certain degree of miscibility, and exhibited much higher tensile strength and water resistivity than did the WPU, casein, and the uncrosslinked blend from WPU and casein. When the ethanedial content was 2 wt %, the tensile strength and elongation at break of crosslinked sheets achieved 19.5 MPa and 148% in the dry state, and 5.0 MPa and 175% in the wet state, respectively. A 2 wt % content of ethanedial plays an important role in the enhancement of mechanical properties, thermal stability, and water resistivity of the blends of WPU and casein as a result of intermolecular crosslinking. This work provided a new protein plastic with good water resistivity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 332–338, 2004     

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。     

稳定水性聚氨酯分散液的合成研究

以聚酯、聚醚混合低聚物二醇为原料 ,采用二级扩链技术[1] 合成了阴离子分散液 ,并研究了聚酯二醇/聚醚二醇、NCO/OH等因素对其性能的影响 ;当原料为 PBA/PEG=(1～ 4)∶ 1 ,NCO/OH=(1 .5～ 1 .8)∶ 1时能够得到黏度、硬度、柔韧性、吸水率、拉伸强度、断裂伸长率、分散性、机械稳定性等综合性能优良的分散液。     

Effect of starch addition on compression‐molded poly(3‐hydroxybutyrate)/starch blends

Because of their biocompatibility and total biodegradability, poly(3‐hydroxybutyrate) (PHB) and starch have attracted attention as promising raw materials for manufacture of single‐use plastic items and biomaterials. PHB/maize starch blends with starch contents in the range of 0–50 wt % were processed in an internal mixer, and their compression‐molded films were characterized by tensile tests, X‐ray diffraction, thermogravimetric analysis, wettability measurements, and scanning electron microscopy. Water and glycerol were used as plasticizers. The results indicated that the thermal degradation behavior of the blends were similar to that of pure PHB films. All the blends showed heterogeneous morphology, wherein starch granules were dispersed in continuous PHB‐rich matrix. Despite the decrease in elongation at break and tensile strength, starch incorporation of up to 30 wt % into PHB matrix resulted in materials as hard as pure PHB films, but exhibiting less crystallinity and more hydrophilic character, which might lead to a higher biodegradation rate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4338–4347, 2006     

新型TMPLA水性聚氨酯分散体的合成及助成膜性能

合成了新型扩链剂三羟甲基丙烷月桂酸单酯(TMPLA)并制备聚氨酯水分散体(n-PUD),取代小分子成膜助剂辅助高玻璃化温度(T_g)聚丙烯酸酯乳液(PA)成膜,以制备高性能超低挥发性有机化合物(VOC)含量水性木器涂料。研究了软/硬段质量比、NCO/OH及TMPLA/BDO摩尔比对n-PUD助成膜性能的影响。结果表明:随软/硬段质量比和NCO/OH摩尔比降低,PUD的助成膜能力增强;TMPLA引入能显著提高n-PUD的助成膜能力,优选TMPLA/BDO摩尔比4/2,NCO/OH摩尔比1.3,软/硬段质量比55/45时,n-PUD/PA按质量比25/75复配乳液在不加成膜助剂条件下能够在5℃形成连续透明成膜,制备的水性木器涂料VOC含量低至30 g·L^-1。     

Miscibility and properties of blend membranes of waterborne polyurethane and carboxymethylchitin

We prepared a series of blend membranes by blending waterborne polyurethane (WPU) and carboxymethylchitin (CMCH) in aqueous systems. The effects of CMCH content on the miscibility, morphology, thermal stability, and mechanical properties of the blend membranes were investigated by dilute solution viscometry (DSV), Fourier transform infrared spectroscopy, wide‐angle X‐ray diffraction (WXRD), scanning electron microscopy, dynamic mechanical analysis (DMA), thermogravimetric analysis, ultraviolet (UV) spectroscopy, and tensile testing. The miscibility parameter of the WPU/CMCH aqueous solution obtained by DSV predicted that the blends of WPU and CMCH were miscible or partially miscible. Moreover, the partial miscibility of the blend membranes over the entire composition range were confirmed by FTIR, WXRD, DMA, and UV spectroscopy to support the conclusion from DSV. New hydrogen bonds were formed between CMCH and WPU in the blend membranes, resulting in strong intermolecular interactions. By inducing the CMCH, we improved the tensile strength, thermostability, and organic solvent resistance of the blend membranes significantly. Therefore, this study not only provided a novel way to prepare an environmentally–friendly material but also expanded the application of chitin and CMCH. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1233–1241, 2003     

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     

Structure–property relationships of polycarbonate diol‐based polyurethanes as a function of soft segment content and molar mass

Segmented thermoplastic polyurethanes (PUs) have been synthesized with polycarbonate diol as soft segment and 4,4′‐diphenylmethane diisocyanate and butanediol as hard segment. Two different series employing two different soft‐segment molar mass, 1000 and 2000 g/mol, and by changing the hard‐segment content from 32 to 67% have been investigated with the aim to elucidate the effect of the different content variations on the properties. Morphological, thermal, and mechanical properties have been studied by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), wide angle X‐ray diffraction, atomic force microscopy, tensile and tear strength, hardness, and specific gravity tests. Properties have been explained from the standpoint of miscibility between hard‐ and soft‐segment microdomains of the tailored segmented PUs through an exhaustive analysis. FTIR, DSC, and DMA measurements revealed that miscibility between hard and soft microdomains increases as the molar mass of the macrodiol decreases. An increase in hard‐segment content entailed the formation of larger hard domains with higher crystallinity what results in superior mechanical properties such as higher tensile stress and tear strength, and hardness. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41704.     

羟乙基封端聚二甲基硅氧烷改性水性聚氨酯的合成

以聚四氢呋喃二醇、异佛尔酮二异氰酸酯（IPDI）和2,2-二羟甲基丙酸（DMPA）为主要原料,羟乙基封端聚二甲基硅氧烷（SHG）为改性剂,采用自乳化法合成了阴离子型有机硅改性水性聚氨酯（WPU）。考察了异氰酸酯基与羟基的量之比（R值）、DMPA用量及SHG用量对WPU及其胶膜性能的影响;通过荧光显微镜分析了改性前后WPU的结构。结果表明：当异氰酸酯基与羟基的量之比为1.2、DMPA质量分数为4%、SHG质量分数为2%时,改性WPU的黏度低、稳定性好;其胶膜的吸水率从17%下降至6%,接触角从30.3°提高至75.7°,耐热性提高;微观形态更规整。