纳米改性水性聚氨酯的制备与性能研究

对纳米SiO2和TiO2进行了TDI(HDI)和PEG的接枝改性,并采用共混法制备了纳米改性水性聚氨酯乳液,电镜观测表明改性后的纳米粒子在乳液中分散均匀,无团聚现象。纳米粒子改性后的水性聚氨酯乳液力学性能比未改性前得到改善和提高,纳米粒子添加量为0.5%时,水性聚氨酯乳液的力学性能最佳,同时吸水率降低了70%,添加的纳米粒子对290~400 nm的紫外光有吸收。     

纳米二氧化硅改性水性聚氨酯分散液的制备与表征

采用沉淀和萃取相结合,硅烷偶联剂A-174包裹改性的方法,制备了改性的纳米二氧化硅含量为15%的聚氧化丙烯二醇分散液,并以其直接作为原料,与聚丙二醇(PPG)、异佛尔酮二异氰酸酯(IPDI)、2,2-二羟甲基丙酸(DMPA)、三羟甲基丙烷(TMP)、三乙胺(TEA)、乙二胺(EDA)等其他原料,制备了一系列纳米SiO2粒子改性WPU样品。讨论了改性纳米SiO2加入量对乳液和涂膜性能的影响。研究表明:纳米SiO2聚醚二元醇分散液与预聚物发生了反应,纳米SiO2均匀分散在预聚物中,乳化后,纳米SiO2粒子在水性聚氨酯中分散性变好,纳米SiO2用量为预聚物质量的2.0%时,得到了稳定的纳米二氧化硅水性聚氨酯分散液,复合涂膜的断裂伸长率为300%,拉伸强度为13 MPa,耐水性、硬度、热稳定性得到较大的提高。     

国内期刊荟萃

水性聚氨酯-SiO2/TiO2复合涂料的制备与研究魏阳等.聚氨酯工业,2004,19(6):17采用溶胶-凝胶法制备了SiO2/TiO2纳米复合微粒,将其分散在聚醚型水性聚氨酯中,制备了新型水性聚氨酯-SiO2/TiO2复合涂料。经FTIR和TEM测试表明,纳米TiO2颗粒表面成功地包覆上SiO2。在聚氨酯乳液中复合微粒粒径为60nm左右;分光光度法测试表明TiO2质量分数为20%的复合微粒在聚氨酯水乳液中具有良好的分散性能;而加入质量分数为1%的十二烷基磺酸钠后,对SiO2/TiO2纳米粉末的分散性能改善最大;力学性能测试表明加入SiO2/TiO2纳米复合微粒质量分数为0.6%时…     

水性聚氨酯包封原生SiO2纳米复合材料的制备及表征

主要研究了SiO2 /水性聚氨酯 (WPU)无机 -有机纳米复合物的制备方法。TEM和动态光散射分析表明 ,SiO2 /WPU纳米复合物粒子分散于WPU胶束内部 ,粒径在 60nm左右 ,具有核 -壳型结构的纳米级微粒。体系有着良好的稳定性和透光性 ,并且其随着SiO2 含量的增加而降低。胶束良好的包覆作用 ,抑制了纳米粒子的团聚 ,是保持其良好的稳定性和较小粒径的原因     

基于欠膨胀射流的SiO2/环氧树脂纳米复合材料制备方法研究

为实现在不添加分散剂的情况下将纳米粒子均匀分散在液相物料中,提出了一种基于欠膨胀射流的液相物料纳米粉添加分散方法.该方法利用欠膨胀射流将纳米粒子以气-粉微气泡的形式分散到液相物料内部,并利用微气泡受高频挤压爆破释放的能量,以及气泡膨胀过程产生的超声波效应和高拉伸场效应来实现纳米粉在液相物料中以纳米尺度粒子分散.设计了相应的分散系统,进行了无分散剂下纳米SiO2/环氧树脂添加分散实验.通过TEM和Tg测试对实验样品进行了表征,结果表明,分散相粒径在15～30nm之间,SiO2纳米颗粒均匀地分散在环氧树脂中.Tg温度比只经过一般高速机械搅拌得到的复合材料提高了约18℃.该方法解决了SiO2纳米粉颗粒在环氧树脂中的团聚问题.     

纳米TiO_2改性水性聚氨酯乳液的制备及性能研究

用硅烷偶联剂KH-550对表面包覆MgO的金红石型纳米TiO2表面进行改性,对纳米粒子进行红外光谱(FT-IR)、扫描电镜(SEM)以及X衍射角表征,SEM分析表明改性后纳米粒子的团聚减少。选取改性效果最佳的纳米粒子用二元醇分散法制备纳米TiO2/水性聚氨酯复合物。对其红外、粒径、黏度等进行表征,结果表明纳米TiO2的加入可提高乳液的耐水性且最佳加入量为0.5%。     

表面引发原子转移自由基聚合合成聚苯乙烯接枝纳米SiO2复合乳液

采用偶联剂对纳米SiO2粒子表面进行处理,将原子转移自由基聚合(ATRP)引发剂引入到SiO2粒子表面合成大分子引发剂,通过细乳液聚合工艺制备了相对分子质量分布窄的聚合物基纳米SiO2复合乳液,利用红外光谱(FT-IR)、X射线光电子能谱(XPS)和凝胶色谱(GPC)等对复合乳液粒子及表面接枝聚苯乙烯进行了表征分析。结果表明:聚合物的相对分子质量在反应过程中随单体转化率的增大呈线性增长趋势,相对分子质量分布较窄(Mw/Mn=1.34),接枝在纳米SiO2粒子表面聚苯乙烯的分子大小比较均匀;TEM和SEM观察表明:通过合成复合乳液使纳米SiO2粒子在涂膜中达到均匀的单分散状态;所合成的纳米复合粒子在功能涂层材料方面具有良好的应用潜能。     

水性聚氨酯-SiO2/TiO2复合涂料的制备与研究

本文采用溶胶-凝胶法,用钛酸四丁酯与正硅酸乙酯制备了纳米级SiO2／TiO2复合微粒,将其分散在聚醚型水性聚氨酯中,制备了新型水性聚氨酯-SiO2／TiO2复合涂料。傅立叶变换红外光谱及透射电镜测试表明纳米TiO2颗粒表面成功地包覆上SiO2,在聚氨酯乳液中复合微粒粒径为60nm左右;分光光度法测试表明TiO2质量分数为20％的复合微粒在聚氨酯水乳液中具有良好的分散性能,而加入质量分数为1％的十二烷基磺酸钠后,对SiO2／TiO2纳米粉末的分散性能改善最大;力学性能测试表明加入SiO2／TiO2纳米复合微粒能有效提高水性聚氨酯的力学性能,当复合微粒质量分数为0.6％时,其力学性能达到最佳。     

SiO2纳米粒子改性填充PC的力学与流变性能

采用SiO2纳米粒子填充改性聚碳酸酯(PC),为使无机纳米粒子在基体PC中分散均匀,经硅烷偶联剂KH-550对SiO2纳米粒子进行表面处理,分析了改性SiO2纳米粒子对复合材料机械与加工性能的影响,并对复合材料进行了分析表征,探讨了无机刚性纳米粒子填充改性典型工程塑料PC的特点并探索其增强增韧的机理,研究了复合物的粘流变性能. 结果表明,改性SiO2纳米粒为球形,在PC基体中分散均匀,湿法改性制备的PC/SiO2纳米粒子复合材料的力学拉伸性能和流变性能最好.     

基于MIS改性的WPU/GO纳米复合乳液的研究

以2-氨基-4-羟基-6-甲基嘧啶(MIS)为改性剂,通过1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐(EDC·HCL)活化羧基制得MIS改性氧化石墨烯(MGO)分散液;并在水性聚氨酯乳化过程中引入MGO分散液制备水性聚氨酯/MIS改性氧化石墨烯(WPU/MGO)纳米复合乳液。通过红外光谱、热重分析、纳米粒度分析、扫描电子显微镜和力学分析对MGO,复合乳液和复合膜的结构与性能进行了表征。结果表明,当MGO的添加量为1%时,MGO在水性聚氨酯中均匀分散,纳米复合膜的杨氏模量、拉伸强度、断裂伸长率和热稳定性均有明显提高。     

纳米二氧化硅水溶胶改性UWPU的研究

通过丙酮法合成光固化水性聚氨酯丙烯酸酯预聚体,用三乙胺中和后在乳化过程中原位引入纳米二氧化硅水溶胶(Wv33、R900、R301)制备二氧化硅/光固化水性聚氨酯(SiO2/UWPU)纳米复合乳液,并进一步通过紫外光固化制备了SiO2/UWPU复合膜。通过电子扫描显微镜(SEM)和电子拉力机研究了不同纳米二氧化硅水溶胶对UWPU/SiO2复合膜的微观结构和力学性能的影响。SEM分析表明表面有机改性的pH值接近中性的硅溶胶(Wv33)较pH为酸性或碱性的硅溶胶在聚氨酯基体中有较好的分散性;应力-应变曲线分析表明Wv33能有效实现对复合膜的增强,即提高了复合膜的储存模量、拉伸强度和邵A硬度。     

Dispersivity of modified ZnO and characterization of polyurethane/ZnO composites

The properties of inorganic nanoparticles/polymer composites depend on the dispersivity of nanoparticles in a polymer matrix. The effect of surface modification on the dispersivity of ZnO nanoparticles in a polyurethane (PU) resin matrix was investigated. The nanocomposites were characterized by scanning electron microscopy (SEM), thermogravimetric analysis, and X‐ray diffraction. The scanning electron micrographs show that ZnO nanoparticles (CDI–SA–APS–ZnO), which were modified by aminopropyltriethoxysilane (APS) and activated stearic acid (SA) by N,N′‐carbonyldiimidazole (CDI), can be homogeneously dispersed and had been encapsulated in the PU phase. The interfacial compatibility between ZnO nanoparticles and PU matrix was significantly improved by hydrophobically modifying ZnO nanoparticles with APS and SA. The tensile strength and elongation at break of PU/CDI–SA–APS–ZnO nanocomposites increased by 82 and 64% respectively, compared with the pure PU material. The thermal stability and ultraviolet‐shielding properties were also improved by incorporating ZnO nanoparticles into the PU matrix. POLYM. COMPOS., 35:237–244, 2014. © 2013 Society of Plastics Engineers     

High performance epoxy resin nanocomposites containing both organic montmorillonite and castor oil-polyurethane

Summary Epoxy resin/polyurethane interpenetrating polymer network nanocomposites with various contents of organophilic montmorillonite (oM-EP/PU nanocomposites) were prepared by a sequential polymeric technique and an in situ intercalation method. X-ray diffraction(XRD), and transmission electronic microscopy(TEM) analysis showed that organophilic montmorillonite (oMMT) disperses uniformly in epoxy resin/polyurethane interpenetrating networks(IPNs), and the intercalated or exfoliated microstructures of oMMT are formed. Differential scanning calorimetry(DSC) test proved that oMMT promotes the compatibility of EP phase and PU phase, and glass transition temperature(T_g) of oM-EP/PU nanocomposites improves with increasing oMMT content. Mechanical properties tests and thermal gravity analysis (TGA) indicated that oMMT and the IPNs of EP and PU exhibit synergistic effect on improving mechanical and thermal properties of pure EP. The mechanism of toughing and reinforcing of oM-EP/PU nanocomposites was further discussed by scanning electronic microscope(SEM).     

环氧改性水性聚氨酯的合成工艺及性能

采用甲苯二异氰酸酯(TDI-80)、聚醚二醇(N220)、二羟甲基丙酸((DMPA)、环氧树脂和丙烯酸羟丙酯(HPA)为主要原料,合成了环氧改性的水性聚氨酯乳液。研究了反应温度、乳化分散速度、中和度和环氧树脂的用量对乳液及涂膜性能的影响。结果表明:当乳化分散速度为4 000~5 000 r/min,中和度为90%~95%,环氧树脂的添加量为4%~6%时,可得到性能较好的乳液。通过环氧树脂改性的水性聚氨酯涂膜具有硬度高、耐水性和力学性能好的特点。     

The effect of silica nanoparticles and carbon nanotubes on the toughness of a thermosetting epoxy polymer

Silica nanoparticles and multiwalled carbon nanotubes (MWCNTs) have been incorporated into an anhydride‐cured epoxy resin to form “hybrid” nanocomposites. A good dispersion of the silica nanoparticles was found to occur, even at relatively high concentrations of the nanoparticles. However, in contrast, the MWCNTs were not so well dispersed but relatively agglomerated. The glass transition temperature of the epoxy polymer was 145°C and was not significantly affected by the addition of the silica nanoparticles or the MWCNTs. The Young's modulus was increased by the addition of the silica nanoparticles, but the addition of up to 0.18 wt % MWCNTs had no further significant effect. The addition of both MWCNTs and silica nanoparticles led to a significant improvement in the fracture toughness of these polymeric nanocomposites. For example, the fracture toughness was increased from 0.69 MPam^1/2 for the unmodified epoxy polymer to 1.03 MPam^1/2 for the hybrid nanocomposite containing both 0.18 wt % MWCNTs and 6.0 wt % silica nanoparticles; the fracture energy was also increased from 133 to 204 J/m². The mechanisms responsible for the enhancements in the measured toughness were identified by observing the fracture surfaces using field‐emission gun scanning electron microscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

纳米SiO2颗粒对PU树脂热稳定性能的影响

采用溶胶-凝胶法制备纳米SiO2颗粒，并以此制备了SiO2／PU复合材料，用扫描电子显微镜、红外光谱仪、量热示差扫描仪和热重法分别表征了纳米复合树脂材料的结构和形态及热稳定性。结果表明，纳米SiO2能够均匀地以纳米尺寸分散于Pu树脂中，并与PU中的基团发生了化学反应，形成了键合。SiO2对PU树脂的耐低温性能影响不大，却提高了树脂的热稳定性能，使树脂的使用温度范围变宽。     

聚氨酯／呋喃树脂互穿聚合物网络性能的研究

用糠醇型呋喃树脂或ＨＦ９２００Ａ环氧型呋喃树脂与聚环氧丙烷醚型聚氨酯制备了互穿聚合物网络（ＩＰＮ）。通过红外光谱和扫描电子显微镜分析了聚氨酯（ＰＵ）／呋喃树脂（ＦＡ）ＩＰＮ网络形成的动力学和微相分离行为，并考察了不同配比下ＩＰＮ的力学性能。实验结果表明，ＰＵ／ＦＡ达到某一比值时，产生互穿聚合物网络的协同效应，可改善聚氨酯的刚性，提高呋喃树脂的抗冲击等性能     

复合薄膜用双组分水性聚氨酯胶黏剂的制备和性能

制备了复合薄膜用双组分水性聚氨酯胶黏剂,初步研究了两种外加型交联剂环氧树脂6360、三聚氰胺-甲醛树脂对胶黏剂性能的影响。红外谱图和差示扫描量热法分析的结果表明在双组分水性聚氨酯胶黏剂中水性聚氨酯和交联剂发生了交联反应。外加交联剂可增加水性聚氨酯胶黏剂的交联度和黏度,从而有效提高胶黏剂的T型剥离强度和耐溶剂性能。环氧树脂较佳加入量在5%左右而三聚氰胺-甲醛树脂约为10%。由双组分水性聚氨酯胶黏剂黏合的PET/PE薄膜在较高温度下适当处理一段时间,其黏合效果更佳。     

Preparation and XPS surface chemical analysis of PS/PU nanocomposites

Aqueous emulsions of anionic polyurethane ionomers, based on polypropylene glycol as soft segment, isophorone diisocyanate as diisocyanate, dimethylolpropionic acid as chain extender and potential ionic center, and triethylamine as neutralizer, were synthesized. They were mixed with styrene monomers to prepare polystyrene–polyurethane (PS/PU) nanocomposites by an evocator. The sizes and distributions of the particles were measured by dynamic light scattering, and the microstructure of the nanocomposites was observed by transmission electron microscope. X‐ray photoelectron spectroscopy (XPS) was used to study the surface characterization of anionic PU and PS/PU nanocomposites. It could be found that the nanoparticles of PU could encapsulate the styrene monomers effectively and the leakage type of every element in PU was not affected by the introduction of Ps. There were more hard segments on the surface of crosslinking PS/PU nanocomposites because of the formation of crosslinking structure and interpenetrating polymer network between PU and PS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3889–3894, 2006     

A novel carbon nanotube nanopaper polyurethane coating for fiber reinforced composite substrates

High performance carbon nanotube (CNT) nanopaper (NP) reinforced polyurethane (PU) nanocomposite coating with high potential for aerospace and automotive applications was successfully fabricated and evaluated in this work. Different PU formulations were used to fabricate nanocomposites to study the effect of hard segment content on resin infiltration and nanocomposite mechanical properties. The process window of PU infiltration into the CNT NP was established by rheology measurements and thermal gravimetric analysis (TGA). The micro-structure morphology of the nanocomposite was characterized by scanning electron microscope (SEM). Uniform CNT distribution in PU matrix was observed in the high-resolution SEM images, which indicated good resin impregnation quality. Based on mechanical properties and process window, a PU formulation was selected as matrix to fabricate NP/PU nanocomposite coating for carbon fiber/epoxy composites (CFPC) substrate. The flexural strength and impact resistance of the CFPC were significantly improved by 9% and 14.7% after applying the NP/PU nanocomposite coating. Aimed at industrial applications, a continuous nanopaper fabrication process was successfully demonstrated in this work. Through the process window study, a continuous process to fabricate nanocomposite is proposed for future scale-up.