一种新型室温固化、耐高温环氧树脂体系及其性能

采用1-己基-3-甲基咪唑四氯化铁盐([C₆mim]FeCl₄)与混合胺复配室温(20 ℃)固化双酚A型环氧树脂E-51,并与其它脂肪胺类室温固化E-51体系在力学性能、热性能、耐老化性能方面的数据进行了比较,同时分析了[C₆mim]FeCl₄不同添加量对固化体系性能的影响,结果显示:[C₆mim]FeCl₄/混合胺复配室温固化E-51体系的室温拉伸强度可达90 MPa,高温(120 ℃)下也保持了良好的力学性能,热失重(5%)分解温度为310 ℃,200 ℃老化7 d后,拉伸强度为28 MPa,是一种可在高温下使用的新型环氧树脂室温固化体系。     

双酚A型环氧磺酸酯的合成与表征

用双酚A型环氧树脂(E-51)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)合成了可用于紫外光固化的双酚A型环氧磺酸酯(AMPS-EP).研究了影响反应的多种因素,优化的合成条件为:以N,N-二甲基甲酰胺(DMF)为溶剂,AMPS与E-51的摩尔投料比为1:0.5,对苯二酚为阻聚剂,用量为环氧树脂质量的0.2％,反应时间...     

环氧改性水性聚氨酯乳液的制备及其膜性能

以聚己内酯二元醇(CAPA)为软段,异佛尔酮二异氰酸酯(IPDI)和六亚甲基二异氰酸酯(HDI)为硬段,环氧树脂E-44为大分子交联剂,经相转化法合成了一系列环氧树脂改性负离子水性聚氨酯(EPPU)自乳化乳液,并制备了改性水性聚氨酯的固化膜.通过FTIR、TGA及接触角、力学性能测试对聚合物结构及其膜性能进行了研究.通过原子力显微镜(AFM)观察膜表面形态和表面粗糙度.乳液粒径及粒径分布通过动态激光光散射法(DLLS)测定.FTIR分析表明环氧树脂的羟基和环氧基都参与了发应.TGA表明,环氧树脂的加入可以提高聚氨酯的热稳定性.随着w(E-44)增大,改性聚氨酯膜的拉伸强度得到改善,断裂伸长率减小.随着w(E-44)增大,乳液粒径增大,薄膜的接触角增大,改性后的PU膜表面光滑度下降,拒水性增强.     

聚苯基硅氧烷与聚甲基苯基硅氧烷改性环氧树脂的合成与性能比较

热熔法制备了一系列聚苯基甲氧基硅氧烷(PPMS)、聚甲基苯基甲氧基硅氧烷(PMPS)改性环氧树脂,通过环氧值、红外光谱(IR)分析表明聚硅氧烷接枝了E-20环氧树脂且环氧基保持不变.探讨了有机硅含量对改性树脂固化体系耐热性能及韧性的影响.实验表明,当E-20环氧树脂与PPMS、PMPS的质量比为7∶3时,改性树脂固化体系的耐热性能明显提高,玻璃化转变温度(Tg)为95.8、88.3℃,分别比改性前提高了9.0℃和1.5℃;质量损失50%时的热分解温度(Td)为476.5、487.8℃,分别比改性前提高了58.3℃和69.5℃.与ED-30固化体系相比,EPMS-30固化物的耐热性能,韧性等力学性能提高的更加明显,并且还具有优良的涂膜性能.     

一种新型液晶环氧树脂的合成表征与固化研究

首次合成了一种不对称联苯和芳香酯型液晶环氧树脂4"-环氧丙氧基苯甲酸-4-环氧丙氧基联苯-4'-酯(EBEPC),利用FT-IR、1H NMR、DSC和POM对其结构和性能进行了表征.结果表明,EBEPC在190℃时可形成明显的向列相液晶.对其同普通固化剂DDM体系的固化反应过程、固化动力学进行了研究,与普通环氧树脂E-51/DDM体系比较,液晶环氧树脂EBEPC体系具有较低的固化反应温度,且表观话化能Ea(54.5kJ/mol)较E-51/DDM体系(60.7kJ/mol)低,EBEPC体系具有更高的反应活性.     

含介晶结构单元化合物改性环氧树脂E—51／DDM固化体系的动态力学行为

合成和表征了含有介晶结构单元的单环氧官能团化合物4-(4'-甲基基苯甲酰氧基)苯基缩水甘油醚(MPEP),以一定比例的MPEP加入到环氧树脂E-51/4,4'-二氨基二苯基甲烷(DDM)固化体系,获得了一系列在高分子链上悬挂介晶结构单元的固化网络结构,并对其动态力学行为进行了表征,侧链上介晶结构单元的引入使固化体系的交联密度降低,链段柔顺性增加,表现为与未加MPEP的体系相比,含有介晶结构单元的体系的玻璃化温度和动态模量下降,而且MPEP的加量越大,玻璃化温度和动态模量下降幅度越大.     

不同交联剂对甲基丙烯酸-β-羟乙酯/E-51双甲基丙烯酸酯聚合物水凝胶性能的影响

以水溶性单体甲基丙烯酸-β-羟乙酯(HEMA)与大分子交联剂E-51双甲基丙烯酸酯(E-51-DMA)(质量比HEMA/E-51-DMA=90/10)为主要原料,分别引入了5种小分子交联剂:N,N′-亚甲基双丙烯酰胺(MBA)、二乙烯基苯(DVB)、双甲基丙烯酸乙二醇酯(EDMA)、1,1,1-三(丙烯酰氧甲基)丙烷(TAP)和2,2,2-三(丙烯酰氧甲基)乙醇(TAE),采用本体聚合方法合成了5个系列的聚合物水凝胶.研究了小分子交联剂的类型及用量对水凝胶溶胀性能、杨氏模量以及有效交联密度ve和聚合物-水相互作用参数χ的影响,并比较了不同交联剂的交联效率.结果表明,随着小分子交联剂用量的增大,水凝胶平衡含水量EWC逐渐降低,聚合物体积分数2逐渐增大,反映聚合物网络结构的有效交联密度ve以及热力学参数聚合物-水相互作用参数χ值也随之增大.通过理论交联密度和有效交联密度的线性拟合,得到所选用的5种小分子交联剂在E-51-DMA10/HEMA90水凝胶体系中的交联效率,其顺序为DVB>EDMA>TAE>MBA≈TAP.     

含三氰乙烯基强吸电子基团的环氧树脂基非线性光学聚合物的合成

非线性光学聚合物材料及其在聚合物电光调制器中的应用是目前国内外研究的前沿。环氧树脂类聚合物具有很好的成膜性及可化学交联性能,是一类非常好的非线性光学聚合物的基体材料。本论文从分子设计的角度出发,将含三氰乙烯基强吸电子取代基及噻吩芳杂环共轭结构非线性光学生色团成功引入环氧树脂类聚合物,并在生色团侧基上引入甲基取代基。结果表明,苯胺残基中侧位甲基取代基对于先驱聚合物的亲电取代反应程度及最后聚合物的紫外-可见光最大吸收波长均有一定的影响,对于没有侧甲基的BP-TA-TC和一个侧甲基取代基的BP-3-TA-TC其官能化度均可以达到80%以上,而对于含两个甲基取代的BP-3,5-TA-TC先驱聚合物其官能化度则相对较低(低于10%)。随着甲基取代数目的增多,最后非线性光学聚合物的最大吸收波长也有不同程度的蓝移。     

双酚A型环氧改性R-122环氧树脂的研究

用双酚A环氧树脂(E-44)改性脂环类环氧树脂(R-122),通过对改性R-122环氧树脂力学性能和热性能的测定,探讨了固化工艺,固化荆体系对改性R-122环氧树脂韧性的影响。结果表明：改性R-122环氧树脂冲击强度提高40％,弯曲强度提高75％,断裂能提高81％,而热变形温度和玻璃化转变温度基本不变。R-122树脂基复合材料随E-44的加入冲击强度和弯曲强度分别提高12％和18％。     

DSC分析及原位FT-IR法对聚合物接枝碳纳米管/环氧树脂固化体系的固化反应的研究

合成了一种扩链脲修饰的多壁碳纳米管(MWCNT-PEG-TU),差示扫描量热分析(DSC)结果表明,MWCNT-PEG-TU可明显提高E-51环氧树脂/双氰双胺(DICY)固化体系的固化反应活性。利用原位傅里叶变换红外光谱(in situ FT-IR)法研究了MWCNT-PEG-TU/E-51环氧树脂/DICY固化体系的等温固化动力学,该固化体系在不同温度下的dα/dt与α的关系曲线较好地符合Kamal自催化反应模型。     

Hollow-glass-microsphere-based Biphenyl Epoxy Resin Composite with Low Dielectric Contant

In this study, rigid 4,4'-diglycidyl(3,3',5,5'-tetramethylbiphenyl) epoxy(TMBP)-based composites were developed by the incorporation of varying percentages of commercial hollow glass microspheres(HGMs, QH-450) into the TMBP resin used for electronic packaging. The thermal and mechanical properties as well as the morphology of all the composites were characterized, and dielectric properties were characterized by advanced analytical techniques. The results reveal that a series of TMBP/QH-450 composites exhibits higher initial degradation temperatures(T_d,5%>300℃), and the residual char and glass transition temperature were clearly improved with QH-450 loading. In addition, all epoxy composites exhibited a lower dielectric constant ranging from 3.74 to 3.06 at 1.2 MHz because the lower dielectric properties of the inert gas used as the core of the QH-450 decreased molecule polarity. Hence, this developed TMBP/QH450 system demonstrates potential applications in electronic packaging.     

Effect of carbon nanotubes dispersed in binder on properties of epoxy nanocomposite

Effect of quality parameters of starting raw materials, native carbon nanotubes (degree of defectiveness, thermal stability, morphology) on the properties of carboxylated and amidated nanotubes produced from these raw materials and on the homogeneity of a dispersion of amidated nanotubes in an epoxy oligomer was studied. The physicomechanical properties of epoxy nanocomposites produced from these dispersions were examined. It was found experimentally that an increase in the defectiveness of native nanotubes leads to a rise in the size of numerous aggregates in dispersions composed of an epoxy resin and amidated carbon nanotubes and, as a result, to deterioration of the physicomechanical characteristics of epoxy nanocomposites based on these dispersions.     

Preparation and Properties of Pyrene-Modified Multi- Walled Carbon Nanotube/Epoxy Resin Nanocomposites

Nanocomposites of multi-walled carbon nanotube (MWCNT)/bis-phenol A type epoxy resin were prepared and physical properties of the nanocomposites were investigated. For the fine dispersion of MWCNT in the epoxy resin, MWCNT was modified with pyrene butyric acid (PBA) in the supercritical carbon dioxide (CO₂). The physical adsorption of PBA on the surface of MWCNTs was studied with a thermogravimetric analyzer and a transmission electron microscopy. The electrical surface resistivities of the nanocomposites showed threshold decreases due to percolations above the critical concentration of the MWCNT. The resistivities showed maximum depending on the concentration and the modification of the surface of the MWCNT with PBA. It is postulated that the dispersion of the MWCNT in epoxy resins resulted in dispersion systems which exhibit rheological properties similar to lyotropic liquid crystalline polymers. The surface resistivities of the MWCNT/epoxy systems reflected the morphological characteristics of the systems which also determined rheological properties of the systems.     

Improved flame retardant properties of epoxy resin by fluorinated MMT/MWCNT additives

Flame retardant additives of montmorillonite (MMT) and multi-walled carbon nanotube (MWCNT) were embedded in epoxy resin to improve the resin's flame retardant properties. MMT was fluorinated to exfoliate its layers and enhance its dispersion into the epoxy resin. The MWCNT was also fluorinated to create hydrophobic functional groups for improved dispersion into the epoxy resin. The MWCNT reduced the degradation rate of the epoxy resin and increased the char yield. Limiting oxygen index also increased showing first order against char yield. The exfoliated MMT acted as an energy storage medium to hinder thermal transfer within the epoxy resin. The activation energy increased almost two times by fluorinated MMT/MWCNT additives. The fluorination of the additives, MMT and MWCNT significantly improved the flame retardant properties of the epoxy resin.     

Effects of surface synergy for the dispersion of short carbon fibers sized by adipic acid modified epoxy resin potassium

The carbon fiber (CF) surface plays a critical role in the performance of CF composite materials. Adipic acid modified epoxy resin potassium (AAEK) prepared with epoxy resin and adipic acid, and KOH was employed as the CF sizing agent. Then, series of surface properties of AAEK‐treated carbon fiber (CF‐AAEK) including surface charge, morphology, and groups were characterized by using Faraday cup, friction coefficient gauge, atomic force microscopy, X‐ray photoelectron spectroscopy, and thermogravimetry. The results indicated that the dispersion coefficient of CF‐AAEK was increased by 1.72 times and there were synergistic effects for the dispersion of short CFs during the sizing treatment process with AAEK. In addition, the flexural strength of treated short CF composite proved to increase by 168%, which evaluated that the better CF dispersion in the matrix was a critical factor for the mechanical property improvement of short CF‐AAEK/epoxy resin composites.     

Tensile,Electrical Conductivity,and Morphological Properties of Carbon Black–Filled Epoxy Composites

This work investigates the effect of carbon black content on the tensile, electrical, and morphological properties of epoxy matrix. Carbon black–filled epoxy composites were obtained by mixing the desired amount of carbon black from bamboo stem (BS-CB), oil palm empty fruit bunch (EFB-CB), and coconut shell (CNS-CB) with the epoxy resin. Tensile and electrical properties of carbon black from three different sources (BS-CB, EFB-CB, and CNS-CB) used to fill epoxy composite with 5% filler loading were measured and the results indicated improvement in tensile and electrical properties. The diffraction patterns of X-ray diffraction (XRD) indicated nonlinear crystalline amorphous structure of the CB.     

Oligoaniline assisted dispersion of carbon nanotubes in epoxy matrix for achieving the nanocomposites with enhanced mechanical,thermal and tribological properties

A critical challenge for initiating many applications of the carbon nanotubes (CNTs) is their dispersion in organic solvent or in polymer melt. In the present study, we described a novel strategy for fabricating carbon nanotubes (CNTs)-reinforced epoxy nanocomposite by utilizing aniline trimer (AT) as the noncovalent dispersant. Tensile testing showed that the tensile modulus of the CNTs-reinforced epoxy composites was considerably improved by adding a small amount of AT functionalized CNTs. Additionally, the as-prepared CNTs-epoxy nanocomposites exhibited superior tribological properties with much lower frictional coefficients and wear rates compared to those of neat epoxy resin. The well dispersed AT-functionalized CNTs in epoxy matrix played an important role in enhancing the mechanical properties, as well as acting as a solid lubricant for improving the tribological performance of epoxy/CNTs nanocomposite.     

Blends of carbon blacks and multiwall carbon nanotubes as reinforcing fillers for hydrocarbon rubbers

The reinforcement of a styrene‐butadiene rubber (SBR) by single fillers—carbon black (CB) or multiwall carbon nanotubes (MWNTs)—or by mixtures of CB and MWNTs, is investigated. The morphologies, mechanical and electrical properties of the composites, are analyzed. A significant improvement in the tensile properties is observed for samples containing a dual phase. Using atomic force (AFM) and transmission electron (TEM) microscopies, we demonstrate that the double loading improves the dispersion of the nanotubes in SBR. Electrical measurements show lower resistivity and a lower percolation threshhold for composites containing blends of fillers, which provides further evidence of better dispersion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 46: 1939–1951, 2008     

两种不同粒径的SBR粒子对透明ABS树脂力学性能影响

从SBR橡胶粒子出发,采用乳液原位悬浮聚合方法合成了一系列透明ABS树脂.采用小粒径SBR橡胶粒子虽然可以获得透明性良好的透明ABS树脂,但树脂的抗冲性能较差.采用大粒径SBR橡胶粒子ABS树脂的透明性明显下降.采用由粒径分别为400nm和70nm两种SBR橡胶粒子所组成的双峰粒子(指粒度分布谱上有两个峰)体系,当二者比例在4/6~6/4范围内,总橡胶粒子含量为15%~18%时,所得到的透明ABS树脂冲击强度已经达到90~120J/m,透光率超过80%.初步探讨了不同增韧体系的ABS树脂的脆韧转变关系;研究了不同粒径橡胶粒子的协同增韧效应.确定了由SBR双峰粒子增韧体系获得具有良好力学和透光性能的ABS树脂的基本条件.     

纳米炭黑复合涂料的制备及其耐蚀性能

纳米炭黑复合涂料的制备及其耐蚀性能;纳米炭黑;复合涂料;制备;耐蚀性