A Study on Structure and Mechanical Properties of Polyurethane/Organic-Montmorillonite Nanocomposites

The intercalated nanocomposites of polyurethane (PU) with organic-montmorillonite (OMMT) treated by cetryltrimethyl ammonium bromide was prepared. The interlayer spacing of PU/OMMT nanocomposites was 3–4 nm. The interface interaction of PU/OMMT nanocomposites was improved compared to that of PU/montmorillonite (MMT) composites. The orderly arrangement of the PU chains was hindered because of strong interface interaction between the silicate layers dispersed in the nanometer and PU chains. By adding 2 wt% OMMT to PU, tensile strength and tear strength of the PU/OMMT composites were increased from 10.5 MPa and 36.4 KN/m to 13.8 MPa and 42.2 KN/m, respectively. The tensile strength and tear strength increased with OMMT content firstly, reaching its maximum when the OMMT content was 8 wt%. After that, the tensile strength and tear strength decreased with the further increase of the OMMT content. Compared to that of PU, the elongation at break of the PU/OMMT nanocomposites increased, indicating that the stretch of PU/OMMT nanocomposites increased.     

Enhanced Thermal and Mechanical Properties in Polyurethane/Au Nanocomposites

Summary: We have prepared waterborne polyurethane (WBPU) thin films containing gold nanoparticles by casting WBPU/Au solutions. The effect of the Au nanoparticle contents on the microstructure and properties of the composite films was investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), field emission scanning electron microscopy (FESEM), transmittance electron microscopy (TEM), FTIR spectroscopy (FTIR) and dynamic mechanical analysis (DMA). The Au nanoparticles initially in the WBPU solution were well dispersed in the WBPU films cast and dried at 60 °C. The thermostability and mechanical properties of the polymer increased with Au contents up to 4.35 × 10^?2 wt.‐%, which was believed to be a result of induced crystallization in the presence of Au nanoparticles. The Au/WBPU nanocomposite containing with 6.5 × 10^?2 wt.‐% of Au resulted in the aggregation of Au particles, which leads to a worsening of the thermal and mechanical properties.

TEM micrograph of nanocomposites filled with 4.35 × 10^?2 wt.‐% of Au nanoparticles.     

不同方法制备聚氨酯/蒙脱土纳米复合材料的力学性能研究

采用3种不同制备方法获得了聚氢酯／蒙脱土（PU／MMT）纳米复合材料。通过对材料力学性能测试,发现制备方法对纳米复合材料的拉伸强度杀Ⅱ断裂伸长率有明显影响。蒙脱土和三羟基聚氧化丙烯醚（GP03）预研磨混合制备法所得的纳米复合材料呈现出较好的力学性能。当有机蒙脱土质量分数为2％时,其拉伸强度和断裂伸长率分别比纯聚氨酯材料提高丁30％-68％。     

The Influence of Crysnanoclay Addition on Mechanical and Thermal Properties of Thermoplastic Polyurethane Elastomeric with Polycarbonate Nanocomposites

A series of crysnanoclay-loaded thermoplastic polyurethane (TPU) elastomer/polycarbonate (PC) nanocomposites have been prepared using twin screw extruders. The physicomechanical properties such as tensile behaviors, flexural properties and impact strength of the composites have been reported. Significant improvement in tensile modulus and flexural modulus were noticed for nanocomposites. The thermal characteristics of nanocomposites have been determined by thermogravimetric analysis (TGA) techniques. Thermal degradation kinetic parameters such as energy of activation (E_a) have been calculated from TGA thermograms for the nanocomposites using three mathematical models namely; Coats–Redfern, Horowitz – Metzger and Broido's methods and the results are compared. The effect of crysnanoclay on the storage modulus (E′), loss modulus (E″), and damping factor (tan δ) as a function of temperature have been measured by dynamic mechanical analysis (DMA). The storage moduli of nanocomposites have been increased after incorporating crysnanoclay in polymer matrix.     

PE-g-SWCNTs材料结晶与力学性能的研究

利用共聚合法来制备单壁碳纳米管接枝聚乙烯(PE)纳米复合材料(PE-g-SWCNTs),在参加反应时能够改善SWCNTs在基体中的分散,同时将PE链接枝到SWCNTs表面上,也能够增强两界面作用力。考察PE-g-SWCNTs纳米复合材料的结晶性能和力学性能的同时,从材料的结构和结晶结构等方面解释了力学性能提高的可能原因。     

T-ZnO/RPUF复合材料力学性能的研究

实验制备了四针状氧化锌（T-ZnO）晶须/硬质聚氨酯泡沫塑料（RPUF）复合材料,研究了复合材料的拉伸性能、压缩性能、冲击性能和阻尼减振性能,并用扫描电子显微镜（SEM）研究了该复合材料的内部形态.结果表明,T-ZnO不能提高复合材料的拉伸性能、压缩性能和冲击性能,但可以提高材料在玻璃态的阻尼性能.     

PUR/OMMT纳米复合材料的制备及性能研究

采用预聚法和原位插层聚合两种方法制备出了聚氨酯(PUR)/有机蒙脱土(OMMT)纳米复合材料,考察了复合材料的力学性能、热稳定性和阻燃性能。结果表明,两种方法制备的复合材料的硬度、拉伸与撕裂强度、断裂伸长率均高于纯PUR。与纯PUR相比,原位插层聚合法制备的复合材料的热分解温度提高了20℃,氧指数提高了23.5%;预聚体法制备的复合材料的分解温度提高了15℃,氧指数提高了13.5%。对比可知,原位插层聚合法制备的复合材料的热稳定性和阻燃性能明显提高,韧性得到增强。     

阳离子型水性聚氨酯合成及力学性能研究

采用异佛尔酮二异氰酸酯(IPDI)、聚四氢呋喃醚二醇(PTMG1000)、N-甲基-二乙醇胺(MDEA)等为主要原料,合成了阳离子型聚氨酯乳液,考察了nNCO/nOH、阳离子亲水性扩链剂MDEA用量及交联剂三羟甲基丙烷(TMP)用量对聚氨酯胶膜力学性能的影响,并采用红外光谱、热失重等手段对聚氨酯胶膜进行了分析。结果表明,当nNCO/nOH为1.4、MDEA质量分数8.54%、TMP质量分数为1.61%时,所得阳离子聚氨酯胶膜的力学性能较好,热稳定性能较高。     

聚氨酯微孔弹性体的合成及力学性能研究

以聚酯多元醇POL-2016、聚醚多元醇PPG-330N、异氰酸酯MT和MDI-100LL、交联剂乙二醇和TMP等为主要原料，采用半预聚法制备聚氨酯微孔弹性体。研究了多元醇的种类及质量比、游离NCO的质量分数、交联剂和固化剂的质量比、及异氰酸酯的质量比对聚氨酯微孔弹性体力学性能的影响，发现当m(POL-2016)／m(PPG-330N)=60／40、NCO质量分数为6％-6．5％时，弹性体综合性能较佳。     

微孔聚醚型聚氨酯弹性体的制备与力学性能研究

以聚氧化丙烯三醇、高活性聚醚聚合物多元醇(HPOP)、二醇扩链剂、水及催化剂等助剂的混合物作为A组分,以聚四氢呋喃二醇(PTMG)、纯MDI和液化MDI为原料合成的半预聚体作为B组分,A组分和B组分按异氰酸酯指数1.1混合,制备微孔聚氨酯弹性体。讨论了预聚体的NCO含量、纯MDI与液化MDI质量比、二醇扩链剂种类和HPOP/聚醚三醇质量比对微孔弹性体力学性能的影响。结果表明,当预聚体NCO含量和纯MDI的用量增加时,微孔弹性体的硬度和拉伸强度增加;微孔弹性体的硬度随HPOP和1,4-丁二醇用量的增加而增加;当HPOP/聚醚三醇质量比为50∶50时,微孔弹性体的拉伸强度和断裂伸长率最高。     

吸氧型无溶剂聚氨酯胶黏剂性能研究

以端羟基聚丁二烯(HTPB)和异佛尔酮二异氰酸酯(IPDI)为原料,制备了聚氨酯胶黏剂预聚体,研究了扩链剂对聚氨酯力学性能及吸氧催化剂对聚氨酯吸氧性能的影响,并分析了吸氧机理。结果表明:随着扩链剂用量的增加,聚氨酯的拉伸强度和硬度提高,而其断裂伸长率呈先提高后降低的趋势,丙三醇的扩链作用优于1,4-丁二醇(BDO);硬脂酸钴作为催化剂时聚氨酯的吸氧量较高;材料的吸氧量、吸氧速率均随硬脂酸钴用量的增加而提高,而乙酸钴用量的增加对提高材料吸氧量没有明显效果。     

多重改性水性聚氨酯的力学性能和粘接性能研究

以聚已内酯二醇、甲苯二异氰酸酯、二羟甲基丙酸为基料,以三羟甲基丙烷(TMP)为交联剂.采用环氧树脂和松香对水性聚氨酯进行改性,制备出环氧树脂和松香改性的聚氨酯复合乳液.重点考察了环氧树脂、松香和三羟甲基丙烷用量对水性聚氨酯粘接性能和力学性能的影响.红外光谱分析表明.环氧树脂和松香参与了体系的反应,最终形成环氧树脂和松香改性水性聚氨醣.胶膜拉伸试验表明,环氧树脂的引入增加了水性聚氨酯胶膜的韧性:向聚氨酯体系中引入松香降低了聚氨酯胶膜的杨氏模量和拉伸强度,同时胶膜的断裂伸长率有所增加;在适宜的用量范围内,三羟甲基丙烷可大大提高水性聚氨酯胶膜的杨氏模量及拉伸强度.粘接试验表明,环氧树脂对聚氨酯胶粘剂的T型剥离强度有显著影响;随松香用量的增加,聚氨酯胶粘剂的初粘力和T型剥离强度均出现峰值;TMP对聚氨醅胶粘剂的T型剥离强度有很大影响,在实验范围内,TMP用量越大,聚氨酯胶粘剂的T型剥离强度越大.当环氧树脂用量为5.65%、松香用量为8.92%、三羟甲基丙烷用量为2.7%时,水性聚氨酯胶膜的力学性能最佳,用该乳液配制的胶粘剂可满足复合软包装对胶粘剂的要求.     

环氧树脂/有机蒙脱土复合材料的制备与力学性能研究

利用插层聚合法制备了环氧树脂/有机蒙脱土(EP/OMMT)复合材料.采用XRD对复合材料进行了表征,并研究了复合材料力学性能.实验表明:环氧树脂/有机蒙脱土形成了剥离型的纳米复合材料结构;环氧树脂中加入适量的有机蒙脱土,可以提高环氧树脂的拉伸强度和冲击强度.当经过改性的OMMT质量分数为5%时,EP/钛酸酯偶联剂(Coupler)-OMMT复合材料的拉伸强度达到51.21 MPa,提高了40.26%;当OMMT质量分数为3%时,EP/Coupler-OMMT复合材料冲击强度达25.31 kJ/m2,提高了34.56%.     

Experimental Investigation of Mechanical and Morphological Properties of Flax-Glass Fiber Reinforced Hybrid Composite using Finite Element Analysis

The use of cellulosic fibers as reinforcing materials in polymer composites has gained popularity due to an increasing trend for developing sustainable materials. In the present experimental study, flax and glass fiber reinforced partially eco-friendly hybrid composites are fabricated with two different fiber orientations of 0° and 90°. The mechanical properties of these composites such as tensile, flexural and impact strengths have been evaluated. From the experiments, it has been observed that the composites with the 0° fiber orientation can hold the maximum tensile strength of 82.71 MPa, flexural strength of 143.99 MPa, and impact strength of 4 kJ/m². Whereas the composites with 90° fiber orientation can withstand the maximum tensile strength of 75.64 MPa, flexural strength of 134.86 MPa, and impact strength of 3.99 kJ/m². Morphological analysis is carried out to analyze fiber matrix interfaces and the structure of the fractured surfaces by using scanning electron microscopy (SEM). The finite element analysis (FEA) has been carried out to predict the resulting important mechanical properties by using ANSYS 12.0. From the results it is found that the experimental results are very close to the results predicted from FEA model values. It is suggested that these hybrid composites can be used as alternate materials for pure synthetic fiber reinforced polymer composite materials.     

稻壳SiO_2/聚氨酯纳米复合材料的制备及性能研究

将酸处理后稻壳在600℃焚烧,得到比表面积为212 m2/g,纯度99.3%的稻壳SiO2纳米凝聚体,用偶联剂γ-氨丙基三乙氧基硅烷(KH550)改性后,SiO2纳米凝聚体在溶液中以纳米状态分散,大部分粒子尺寸约30~50 nm。将其与聚氨酯(PU)复合,探讨了不同SiO2含量复合材料的力学性能、热分解性能以及吸水性。研究结果表明:与纯PU相比,稻壳SiO2/PU纳米复合材料的力学性能有不同程度的提高,其耐热性能和耐水性明显增强。     

Study of Electromagnetic Properties of Fabricated NiFe2O4/Polyurethane Nanocomposites

Nickel ferrite loaded (NiFe₂O₄) segmented polyurethane (SPU) nanocomposites prepared by melt mixing method using microcompounder at temperature 185 °C in recirculation mode to ensure proper dispersion and distribution of nanoparticles at optimized residency time of 5 min. Three different weight percentages of nanocomposites (3, 5, and 10 wt %) was prepared and studied the electromagnetic property of nanocomposites obtained from complex permittivity and permeability. The effect of nanofiller (NiFe₂O₄) has been studied to assess their thermal properties using thermogravimetric analysis, differential scanning calorimetry, and thermomechanical analysis. The nanocomposites (NiFe₂O₄/SPU) have further been studied using FE-SEM, and the micrographs show embedded NiFe₂O₄ filler uniformly dispersed in SPU matrix without agglomeration (size 20–40 nm). It is also evident that further loading of nanofiller resulted in saturation effect yielding no applicable change in thermal behavior and revealed lesser melting enthalpy due to the coalescence of the nanofillers. X-ray diffraction and vibrating sample magnetometer also support the formation of the nanocomposite. The electric and magnetic properties of NiFe₂O₄ incorporated nanocomposite (NiFe₂O₄/SPU) may have potential application in microwave absorption. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48645.     

阳离子型水性聚氨酯耐热性及力学性能研究

以丙三醇和马来酸酐为原料合成亲水性UV固化交联剂(丙三醇-马来酸酐低聚物)(MLGLY),以均苯四甲酸酐和乙醇胺为原料合成二羟基均苯酰亚胺(HEPMI);再以二环己基甲烷二异氰酸酯(H12MDI)、六亚甲基二异氰酸酯(HDI)、聚氧化丙烯二醇(PPG-600)、N-甲基二乙醇胺(MDEA)、HEPMI、MLGLY等为主要原料,制备了一系列聚酰亚胺改性阳离子型水性聚氨酯(WPU)。讨论了HEPMI含量对WPU膜的力学性能和耐热性能的影响。结果表明,HEPMI含量增加能明显改善WPU膜的耐热性和力学性能。     

Investigation on the Mechanical and Thermal Properties of Intercalated Epoxy/Layered Silicate Nanocomposites

Epoxy resin/layered silicate nanocomposites with various clay contents were prepared. The structural studies showed the intercalation of epoxy polymer chains into the clay galleries. The adhesion analysis of nanocomposite coating films on metallic substrates showed the excellent adhesion of epoxy-based nanocomposite coatings on iron plates, especially in lower clay loadings. According to the hardness test results, the organoclay minerals caused the increasing of the hardness of epoxy nanocomposites. The thermal properties of nanocomposites were evaluated by means of DSC and TGA analysis. The tensile and compression strengths of cured epoxy/clay systems were also investigated.     

聚氨酯弹性体的力学性能影响因素研究

研究了合成方法,软段及硬段组成结构,熟化条件等因素对聚氨酯弹性和学性能的影响,结果表明,聚氨酯弹性体的结构与组成,以及由此引起微相分离程度的变化,是影响弹性体性能的重要因素,不同的低聚物二醇,二异氰酸酯及扩链剂合成的弹性体性能不同,采用预聚法,以及适当熟化有助于提高弹性体的性能。