Preparation and characterization of one-component polyurethane powder adhesives by the solution polymerization technology

A new technology integrating the synthesis and granulation was adopted to prepare the one-component polyurethane powder adhesives (PPAs) by the solution polymerization. The influence of R_total, neutralization, and types of dispersion solution on the properties of PPAs was investigated. It was found that the initial melting temperature increased and storage stability decreased with increasing R_total. The neutralization reaction between the carboxylic group and amino group made the reduction of the sizing temperature and the increase of the T-peel adhesion strength. The granulation behaviors of the polyurethane (PU) prepolymer under different dispersion solutions showed that the PU prepolymer can be effectively blocked by the 20–30 wt % NaHSO₃ or n-butyl alcohol. Furthermore, the blocked polymers formed small particles with the ideal sizing temperature and peel strength. The excellent adhesive property and thermal stability of PPAs could meet the requirements of the industrial gluing in the fields of packaging, lining, and footwear. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47898.     

不同无机填料对聚氨酯阻尼材料性能的影响

以聚氧化丙烯二醇（PPG）、二苯基甲烷二异氰酸酯（MDI）、端羟基硅油为原料,1,4丁二醇（BDO）作为扩链剂,采用预聚体法制得无填料填充的聚氨酯、不同质量分数绢云母改性聚氨酯、不同质量分数滑石粉改性聚氨酯的3种复合材料,采用动态力学分析（DMA）、热重分析（TGA）、扫描电子显微镜（SEM）对复合材料的阻尼性能、耐热性能、表面形貌进行表征,并对复合材料的力学性能进行测试。结果表明,添加两种不同无机填料后,复合材料的热稳定性、力学性能以及阻尼性能都有不同程度的改善。添加10%的绢云母和10%的滑石粉后,最大损耗因子（tanδ）分别由0.372提升至0.436和0.440,而T _g向低温方向偏移,10%绢云母改性的复合材料拉伸强度、断裂伸长率、邵氏硬度分别由5.16MPa、432%、65提高到8.47MPa、468%、85;10%滑石粉改性后复合材料的拉伸强度、断裂伸长率、邵氏硬度提高至7MPa、470%、82;在失重率为5%时,相比于未添加无机填料的聚氨酯,10%绢云母和10%滑石粉改性后的初始分解温度分别提高了52.67℃和55.8℃。     

Optimization of acoustic performances of a new tung oleic acid-based composite polyurethane foam

Bio-based polyurethane (PU) foam, different from traditional PU foam, is a new green environmental acoustic material. It can be used in the field of automobiles. In this work, a new tung oleic acid-based composite PU (TOAPU) foam was prepared using tung oleic acid-based polyol and polyether polyols 3630. It is important to optimize the formulation of TOAPU foam for better acoustic performance. The effect of each component on the acoustic performance of TOAPU is ordered by screening test. A1, silicone, and A33, the three components that have the greatest impact on the acoustic performance of TOAPU, are used as variables. The response surface method is used to create the model of the effects of different components on the acoustic properties of TOAPU. The model was optimized by using nondominated sorting genetic algorithm II method. The optimized acoustic performance property of TOAPU foams was synthesized by adding 0.27 g of A1, 1.03 g of A33, and 2.81 g of silicone oil. The experimental results show that the mean sound absorption coefficient and transmission loss can reach 0.515 and 21.389 dB. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47861.     

Biodegradation of polyurethane-polyhydroxybutyrate elastomeric composite investigated from morphological and structural viewpoint

Morphological, structural, and tensile changes of polyurethane-poly(3-hydroxybutyrate) (PU-PHB) elastomeric composites were evaluated after accelerated test in standard compost media. Size of PHB particles together with their uniform dispersion in the matrix were found to be key parameters for material's resistivity against degradation media. PU-PHB composite films were synthesized by the “green” solvent free method, where commercially available PHB (PHB-COM) and PHB produced by bacterium Cupriavidus necator H16 (PHB-BUT) were both used in the amount of 1, 5, and 10 wt % in composites. Scanning electron microscopy revealed excellent dispersion of PHB-COM microparticles in the PU matrix resulting in negligible weight losses of the material (max 0.7 wt %). On the contrary, PHB-BUT particles were agglomerated which promoted partial degradation of the material (max 3.3 wt % loss) manifested by holes on the surface but without severe damage (e.g. fragmentation). Structural analysis confirmed lower crystallinity and less ordered crystalline phase of PHB after the degradation test, particularly in composites made of PHB-BUT. Moreover, the materials were less stiff after the composting test, but beneficial with higher elongation at break. Such properties are favorable for the use of renewable PHB in the current industrial applications of PU elastomers. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46909.     

Preparation of sorbitol-based polyurethanes and their semiinterpenetrating polymer networks

Sorbitol is a useful agro-based substance that is inexpensive and commercially available. In the interest of adding value to bio-based raw materials, we have synthesized polyurethanes from sorbitol and toluene-2,4-diisocyanate (TDI) through both conventional heat and microwave processes. Relative to conventional heat, the microwave process achieved the same reaction at a faster rate, thereby saving time and energy. The nature of the resulting polyurethane products depended on the stoichiometry of the reaction. At increasing TDI levels, a viscous liquid, a soft gel, or a hard thermoset could be obtained. The polymers were fully characterized with ¹³C-NMR, Fourier transform infrared, size exclusion chromatography, and thermogravimetric analysis. The polyurethanes obtained near the gel point could be used to make semiinterpenetrating polymer networks (semi-IPNs) with a second polymer, thereby imparting some of the properties of the second polymer onto the sorbitol-based polyurethane. For illustration, the sorbitol-based polyurethane semi-IPNs were made in combination with poly(vinyl pyrrolidone) and poly(lactic acid). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47602.     

A Green Method to Fabricate Polyethyleneimine-Alginate Multilayer Coatings Modified Polyurethane Foam for Cu2+ Adsorption from Aqueous Solution

In this study, flexible polyurethane foam (FPUF) was modified with bio-based coatings composed of polyethylenimine (PEI) and alginate (ALG), fabricated by layer-by-layer (LbL) self-assembly. LbL self-assembled coatings modified FPUFs were studied for their potentials for removing Cu²⁺ ions from aqueous solutions by using batch adsorption technique, as a function of assembled bilayers number, pH value, carrier amount and adsorption time. The maximum adsorption capacity of the modified FPUF was shown to be 54 mg/g for Cu²⁺. Results suggested that the LbL self-assembly could potentially be a promising cost-effective technique for fabricating advanced adsorbent materials for removing pollutants from wastewater.     

The effect of natural silk fibroin microparticles on the physical properties and drug release behavior of biomedical polyurethane filament

In this study, filaments comprising natural silk fibroin microparticles (NSFP) and biomedical polyurethane (BPU) were prepared via wet-spinning as a reusable-controlled drug-delivery system. The rheological properties of the spinning solution were studied to examine the effect of NSFP on the BPU/NSFP filament formation. The influences of NSFP content and spinning conditions on the morphology, molecular interactions, mechanical properties, and swelling performance of BPU/NSFP filaments were also investigated. The morphology and mechanical property studies showed that NSPF and BPU exhibit good compatibility. The capacity of the BPU/NSFP filaments as drug loading carriers and drug release behavior were studied by spectroscopy. The presence of NSFP in the drug controlled system increase the drug loading amount and enhance the drug release time. This paper presents a well-designed manufacturing method for preparing BPU/NSFP filaments with good controlled drug delivery.     

芳纶/超高分子量聚乙烯织物增强聚氨酯夹芯复合材料制备及其力学性能

为开发出一种柔性防护材料,采用超高分子量聚乙烯纤维(UHMWPE)与芳纶制备的平纹织物作为增强面板,软式聚氨酯(PU)作为芯材,利用纺织技术与一体发泡技术相结合制备了具有良好缓冲性能的夹芯结构柔性复合材料。同时,选用面密度相同的锦纶非织造布及玄武岩平纹布作为增强面板对比材料,对3类夹芯复合材料进行静态与动态力学性能测试。结果表明:芳纶/UHMWPE织物增强夹芯复合材料的力学性能优良,经向拉伸断裂强力为1 930 N,断裂伸长率为5.8%;纬向拉伸断裂强力为1 744 N,断裂伸长率为6.5%;在7.5 mm处进入压实阶段,压缩形变为93%;冲击破坏强力为1 260 N, 吸收的总能量为13.4 J,能量密度为4.95 J/g;芳纶/UHMWPE织物增强夹芯复合材料在保证质轻的基础上,具有良好的能量吸收效果。     

自着色水性聚氨酯制备及其在棉织物涂层中的应用

为解决低分子染料的耐热迁移性差和涂层色浆配制时外添加涂料、染料等着色剂的烦琐性,将1-氨基-4-羟基-2(6-羟基己氧基)蒽醌通过共价键引入水性聚氨酯骨架中合成端羟基自着色水性聚氨酯。借助红外光谱仪、紫外-可见光谱仪和热重分析仪研究了自着色水性聚氨酯的化学结构和热稳定性。考察了蒽醌发色体质量分数、固化剂质量分数和焙烘条件对涂层棉织物K/S值、色牢度和手感的影响。结果表明:随着自着色水性聚氨酯制备过程中蒽醌发色体质量分数增加,涂层棉织物K/S值增大;当固化剂质量分数为20%,于150 ℃焙烘5 min,涂层棉织物K/S值为5.20,干、湿摩擦色牢度为4~5级,褪色牢度为3~4级,沾色牢度为4~5级,手感为3级。     

提高水基聚氨酯树脂凃膜耐水性的研究

对丙酮法合成的水基聚氨酯树脂凃膜耐水性的提高进行了报导。作者选用了硬脂酸单甘脂(GMS)、聚硅氧烷二醇作为小分子扩链剂并以二聚酸聚酯二醇作为软段合成了含有侧链的水基聚氨酯树脂系列、探讨了DMPA用量、聚氨酯侧链结构种类等因素对水基聚氨酯树脂分散体涂膜耐水性的影响。合成出了耐水性更好的水基聚氨酯树脂皮革涂饰剂。