中空多壳层TiO2填充对环氧树脂复合材料力学性能的影响

为改善环氧树脂(EP)材料的力学性能, 采用次序模板法合成了TiO₂中空多壳层结构(HoMS)材料, 利用偶联剂对获得的TiO₂ HoMSs进行接枝改性后填充到EP中, 制备了TiO₂ HoMSs/EP复合材料; 并与单壳层TiO₂中空结构进行比较, 研究了壳层数和偶联剂改性对复合材料力学性能的影响规律. 结果表明, 随着壳层数的增加, 复合材料的力学性能增强, 并且偶联剂改性的TiO₂ HoMSs可进一步提高复合材料的力学性能. 在该体系中, 经硅烷偶联剂KH-560改性后的三壳层TiO₂ HoMSs(3S-TiO₂ HoMSs)/EP复合材料的拉伸强度、 断裂伸长率和冲击强度可分别达到71.66 MPa, 7.4%和35.81 kJ/m². 扫描电子显微镜(SEM)断面形貌表征结果显示, 相较于纯EP材料, TiO₂ HoMSs/EP复合材料的断面更加粗糙, 说明TiO₂ HoMSs材料起到了吸收外界应力和阻碍裂纹扩展的作用, 提高了复合材料的韧性, 提升了复合材料的冲击性能.     

Effect of Functionalized Magnetite Nanoparticles and Diaminoxanthone on the Curing,Thermal Degradation Kinetic and Corrosion Property of Diglycidyl Ether of Bisphenol A-Based Epoxy Resin

To prepare a high-performance epoxy resin with excellent thermal, chemical and corrosion stability, diaminoxanthone（DAX） was used to cure diglycidylether of bisphenol-A（DGEBA）-based epoxy resin and blend of DGEBA with functionalized Fe3O4 nanoparticles. Kinetic parameters of curing and thermal degradation of epoxy resin systems were estimated by differential scanning calorimetry（DSC） and thermogravimetric analysis（TGA）, respectively. The 10% weight loss temperature has been increased from 340 °C to 366 °C and there was an increase in the char yield from 32.6% to 45.3% for the above systems. The corrosion performance of epoxy coated carbon steel was examined by potentiodynamic polarization, along with immersion test in 1.0 mol/L HCl solution. The results showed that epoxy resins cured with DAX had low tendency to corrosion. In addition, the cured epoxy resin containing 10% Fe3O4 had higher anticorrosion activity than bare DGEBA system. The results showed that functionalized Fe3O4 nanoparticles enhanced char formation and improved the thermal stability as well as anticorrosion activity of the resin.     

碳纤维三向织物/环氧树脂复合材料的制备与力学性能

选择不同纱线间距[即二经(纬)纱之间的中心距]尺寸的碳纤维三向织物,采用热压成型技术制备了碳纤维三向织物/环氧树脂复合材料.研究了纱线间距及样品裁剪角度等对力学性能的影响,并与碳纤维二向织物/环氧树脂复合材料的力学性能进行对比.结果表明,随着纱线间距尺寸从2 mm增加到6 mm,0°方向断裂强度从221. 7 MPa下降到148. 1 MPa,撕裂强力从1000 N下降到600 N; 90°方向断裂强度从50. 0MPa下降到22. 1 MPa,撕裂强力从330 N下降到100 N;顶破强力从424 N下降到216 N.这些力学性能的逐渐降低是单位面积的碳纤维增强体含量减少和织物的孔洞增大共同作用的结果.纱线间距为2 mm的碳纤维三向织物复合材料在0°(以纬纱为基准),30°,45°,60°和90°方向的断裂强度分别为221. 7,48. 5,44. 3,227. 7和50. 0 MPa,即断裂强度在0°和60°方向大于在30°,45°及90°方向.由三向织物的编织原理可知,0°与60°方向完全相同,因此其断裂强度相似,且样品中有一组纱线与外加载荷平行,对形变破坏具有一定的约束作用,而...     

端噁唑啉聚醚对环氧树脂的固化与增韧作用的研究

用IR、DSC等分析方法研究了端2-噁唑啉聚环氧丙烷(活性聚醚)与环氧树脂的固化反应,对固化机理作了讨论。并考察了不同分子量活性聚醚对环氧树脂的增韧作用。结果表明,此活性聚醚对环氧树脂增韧效果明显,固化树脂综合性能较好。     

聚[丙烯酸甲酯-甲基丙烯酸2-(二甲氨基)乙酯]/环氧树脂IPN力学性能的研究

用同步法合成聚[丙烯酸甲酯-甲基丙烯酸2-(二甲氨基)乙酯]/环氧树脂(P(MA-DMA)/EP)互穿聚合物网络(IPN),对其力学性能进行了研究,结果表明,该体系IPN由于两网络间接枝导致相客性比较好,动态力学谱仅出现一个转变温度,当P(MA-DMA)/EP=20/80时,力学性能显示正协同效应,对环氧树脂的增韧效果最佳,不同组成比的IPNT_g实-T_g计与(d_实-d_计)差值成正比。     

聚离子液体修饰碳纳米管及其对环氧树脂力学性能的影响

为改善多壁碳纳米管(MWCNTs)在环氧树脂(EP)中的分散性和界面性质,以1-乙烯基-3-丁基咪唑六氟磷酸盐([VBIM]PF6)为单体合成聚离子液体(PIL),用于MWCNTs的表面改性.用热重分析(TG),拉曼光谱(Raman)和扫描电镜(SEM)对改性碳纳米管(PIL-CNTs)进行了表征.结果表明,PIL可吸附在MWCNTs表面且不改变MWCNTs的电子结构.与原始MWCNTs相比,PIL-CNTs在丙酮中的分散性更好.在EP中加入0.5 wt%的PIL-CNTs,以4,4'-二氨基二苯甲烷(DDM)为固化剂制备环氧树脂固化物.动态力学(DMA)研究表明,PIL-CNTs提高了EP的储能模量,玻璃化温度比纯EP和MWCNTs/EP分别提高了5.6℃和3.3℃;PILCNTs/EP的拉伸强度,弯曲强度和冲击强度较纯EP分别提高了35.2%,26.4%和45.0%.拉伸断面的SEM可看出PIL-CNTs在复合材料中的分散性和与环氧树脂基体的界面结合力均优于原始MWCNTs.     

Ethylene-Octene Copolymer-Nanosilica Nanocomposites: Effects of Epoxy Resin Functionalized Nanosilica on Morphology,Mechanical, Dynamic Mechanical and Thermal Properties

A comparative study of the structural, thermal, mechanical and thermomechanical properties of ethylene-octene copolymer 1

1 Ethylene-octene copolymer is produced using Dow's INSITETM ™ constrained geometry catalyst and process technology. ENGAGE the trade name of this copolymer.

(mPE) 2

2 This copolymer will be represented as mPE .

nanocomposites synthesized with pure nanosilica (NS) and nanosilica-functionalized with diglycidyl ether of bisphenol-A (ENS) has been reported. These nanocomposites were prepared using “melt mixing” method at a constant loading level of 2.5 wt. %. The effects of pure nanosilica (NS) and epoxy resin-functionalized-nanosilica (ENS) on the above mentioned properties of ethylene-octene copolymer were analyzed by wide-angle-x-ray diffractometer (WAXD), transmission electron microscope (TEM), thermo gravimetric analyzer (TGA), differential scanning calorimeter (DSC), dynamic mechanical analyzer (DMA) and scanning electron microscope (SEM). TEM studies have shown a better dispersion of nanoparticles in case of ethylene-octene copolymer-epoxy resin-functionalized-nanosilica nanocomposite (mPE-ENS) than that of ethylene-octene copolymer-nanosilica nanocomposite (mPE-NS). The tensile tests show that organic modification of nanosilica particles brings up an appreciable increase in yield strength, ultimate tensile strength and elongation at break of the polymer. DMA studies have shown an increase in the storage modulus and glass transition temperature for mPE-ENS with respect to mPE-NS. Further, the TGA results have shown a higher thermal stability for mPE-ENS in comparison to mPE-NS.     

含介晶单元的反应性增韧剂改性环氧树脂研究

合成了既含聚乙二醇醚(PEG)柔性链、又含刚性液晶结构单元的活性增韧促进剂(LCEU_PEG),对其促进环氧树脂/双氰双胺体系的固化反应活性、反应机制;增韧剂的用量与动态力学性能、冲击性能之间的关系进行了研究.结果表明:LCEU_PEG对E-51/dicy固化体系具有明显的促进作用,能有效的降低固化反应活化能及固化反应温度;改性体系的冲击强度较单纯的E-51/dicy体系提高3～7倍;模量较未增韧体系有所提高.     

Effect of Molybdenum Disulfide Exfoliation Conditions on the Mechanical Properties of Epoxy Nanocomposites

In this work, the MoS2 fillers were prepared through chemical exfoliation method and used as fillers to fabricate epoxy (EP)/MoS2 nanocomposites. The effects of molybdenum disulfide (MoS2) intercalation conditions on the properties of EP/MoS2 nanocomposites were investigated. As the intercalation time was prolonged, the surface of MoS2 exhibited a totally crumpled structure and more functional groups formed. Because of the higher functional group concentration, the interfacial adhesion force between EP and MoS2 was enhanced. With the addition of 1.0 wt% exfoliated MoS2 fillers, the tensile strength and tensile modulus of EP were even improved ~500% and ~6800%, respectively. Therefore, this work provides a facile way to produce high-performance EP nanocomposites.     

聚酰胺1010／聚乙烯－马来酸酐接枝共聚物共混物力学和热学性能研究

为了表明马来酸酐接枝聚烯烃后对聚酰胺的相容作用，本文研究了聚酰胺１０１０（ＰＡ１０１０）／聚乙烯－马来酸酐接枝共聚物（ＰＥ－ｇ－ＭＡＨ）共混物在不同ＭＡＨ接枝量下的结晶性与力学性能。研究表明，ＭＡＨ的存在导致ＰＥ－ｇ－ＭＡＨ－ｃｏ－ＰＡ１０１０共聚物的形成，而该共聚物在标题共混物中起着相容剂的作用。共混物的结晶性能变化显示了共混组分间存在一定程度的混溶性。在一定的ＭＡＨ含量内，标题共混物具有协同效应。     

化学结构变化对刚棒状环氧树脂相行为和热力学性能的影响

用线性酚醛树脂(PN)和4-氨基苯基氨基砜(SAA)作为固化剂, 与刚性棒状环氧树脂联苯环氧(DGEBP)、四甲基联苯环氧(DGETMBP)和传统双酚A环氧树脂(DGEBA)分别进行固化. 研究了固化剂和环氧树脂化学结构的改变对热固网络相行为和热力学性能的影响. 结果表明, 刚性环氧网络比传统的DGEBA具有更好的热力学性能. DGEBP可形成不同类型的取向网络, 而取向态的类型也直接影响了热固网络的热力学性能. 用扫描电镜(SEM)观察不同网络体系的断裂面结构, 发现取向的刚性棒状环氧网络的断裂面呈韧性断裂, 而其它无定形环氧网络则呈典型的脆性断裂.     

环氧树脂掺量对发光树脂透水混凝土性能的影响

选择环氧树脂E51作为改性填料,制备出一系列不同树脂质量分数（0%、2%、4%和6%）的发光树脂透水混凝土。环氧树脂的引入使发光树脂透水混凝土的抗压强度和抗折强度均得到了提高,且随着树脂掺量的增加呈现出先升高后降低的趋势,在树脂质量分数为4%时,抗压强度和抗折强度均达到最大值21.7和6.11 MPa,发光树脂透水混凝土的透水系数随着环氧树脂质量分数的增加呈现出先降低后升高的趋势,在4%时透水系数最低为5.1 mm/s。微观形貌分析发现未经改性的环氧树脂透水混凝土的断面处有明显的裂痕和气孔,整体结构较为疏松,在引入环氧树脂后,裂痕和气孔的数量明显减少,整体结合较为紧密,发光树脂透水混凝土的发光时间与树脂质量分数关系不大,且发光透水混凝土在光照1 h下可以保持超过5 h的较为高效的发光时间。     

碳材料表面特性及形貌对阻燃环氧树脂燃烧和热解行为的影响

将制备的4种植物基多孔碳,甘蔗渣炭(SBC)、竹叶炭(BLC)、稻壳炭(RHC)及竹茎炭(BSC),以及购置的椰壳炭(CSC)、果壳炭(NSC)、碳纳米管(CNTs)及可膨胀石墨(EG)分别与聚磷酸铵(APP)复合用于阻燃环氧树脂(EP),研究了碳材料比表面积、表面活性及微观形貌对APP阻燃EP燃烧和热解行为的影响.物理吸附仪、X射线光电子能谱仪(XPS)、扫描电镜研究指出,颗粒状竹茎多孔碳(BSC)的比表面积(2063m2/g)及表面活性基团C—O—、C≡O及COO—的比例显著大于其他碳材料;各种碳材料均以微米级尺度分布于阻燃EP基体.氧指数(LOI)、UL 94垂直燃烧及锥形量热仪研究表明,0.8 wt%BSC或CNTs与3.1 wt%APP协同阻燃EP的LOI分别由EP的24.6%提高到27.3%和27.6%,UL 94均为V-1级,峰值热释放速率分别比EP/APP降低了27%和28%.碳材料的协同阻燃效果主要取决于微观形貌;对于颗粒状多孔碳,其比表面积、O/C比及表面活性基团比例越大,协同阻燃效果越好.热失重分析、共聚焦拉曼光谱及XPS研究证实,碳材料提高了EP/APP复合材料的初始分解温度和残炭量;大的比表面及表面活性,以及管状形貌能够提高环氧树脂复合材料高温残炭量、促进残炭类石墨化转变、改善残炭耐高温氧化性能.     

Influence of Mixing Conditions on Morphologies and Properties of MMT/Epoxy Resin Composite Materials

Montmorillonite(MMT) was directly modified with hexadecyl trimethyl ammonium bromide. The interlayer spacing of the organophilic montmorillonite(organo-MMT) corresponding to the d(001) plane peak was 2.21 nm. The influences of the content of organo-MMT and mixing conditions including mixing temperature and mixing time on the intercalation and exfoliation structures of MMT/epoxy resin composites were investigated by wide X-ray diffraction(WXRD). The X-ray patterns reveal that organo-MMT was intercalated by the epoxy resin during mixing process. Only under certain mixing conditions, could the exfoliation nanocomposites be formed. The mechanical and thermal properties of the composites were measured. The results indicate that the composites have better mechanical properties and higher Tg than those of the pristine epoxy resin.     

带甲基侧基的环氧树脂增容剂对炭黑在丁苯橡胶中分散度的影响

用自制的带甲基侧基的环氧树脂(TMBP)作为界面增容剂, 从拉伸性能、键合胶含量、动态性能、扫描电镜和流变性能等方面, 研究了TMBP对炭黑在丁苯橡胶中分散度的影响, 并与市售通用双酚A型环氧树脂(E-51)和橡胶工业常用软化剂邻苯二甲酸二辛酯(DOP)进行了比较. 结果表明, 带甲基侧基的环氧树脂TMBP在提高炭黑分散性方面的效果远比E-51好， 其作用模式具有典型的增容特性.     

Thermal Aging Effect on Mechanical Properties of Polyurethane

This study concerns the effect of thermal aging on mechanical properties of polyurethane. Polyurethane samples were exposed at 85° and 120°C under inert atmosphere. Mechanical tests were carried out on these samples the aging period. Tensile tests were performed to see the effect of aging on elastic modulus (E), stress (σ_r), and strain (?_r) at break. It was shown that there are two distinct periods. Due to aging, E and σ_r increase in the first period, then they decrease in the second period. ?_r decreases first and then increases. Fatigue tests were performed on unaged and aged samples. It was shown that the fatigue behavior of polyurethane (PU) is improved the same way during the first stage of aging. In the second step, the number of cycles to failure increases due to aging. The results show that aging has an important effect on mechanical properties of PU. The strain at break decreases during the first step of aging due to post-cross-linking and then increases due to chain scission in the network. Based on these results, the effect of cross-linking and chain scission on the mechanical properties of PU was discussed.     

Thermal,Rheological and Mechanical Properties of Biodegradable Poly(propylene carbonate)/Epoxidized Soybean Oil Blends

Biodegradable poly(propylene carbonate)(PPC)/epoxidized soybean oil(ESO) blends with different component ratios were prepared by melt blending to improve the performance of PPC. The phase morphology, thermal properties, rheological properties and mechanical properties of the blends were investigated in detail. SEM examination revealed good interfacial adhesion between PPC matrix and ESO.According to DSC and DMA, as the content of ESO increased, the glass transition temperature of the PPC compone...     

Effect of Chemical Treatment on the Mechanical and Water Absorption Properties of Coir Pith/Nylon/Epoxy Sandwich Composites

Multilayered coir pith/nylon fabric/epoxy hybrid composites were fabricated by the hand lay-up technique. Coir pith was subjected to chemical treatment before processing and the volume fraction of coir pith was maintained in the range of 60–65%. The effect of treatment was analyzed by SEM and optical microscopy. The effects of layering and treatment on the mechanical and water transport nature of composite were analyzed. The mechanical properties of the composite decreased on exposure to water. However, the retention of impact strength increased with chemical treatment of coir pith.     

聚醚链段长度对氨基聚醚-环氧树脂力学性能的影响

以柔性端氨基聚醚(BATPE)和双酚A环氧树脂(DGEBA)为原料, 制备了无微相分离结构的无定型AB交联热固性树脂. 测试了3种不同聚乙二醇(PEG)链段长度(M_PE)的BATPE-DGEBA环氧树脂固化产物的应力-应变曲线、动态力学温度谱和冲击断面形貌. 结果表明, 在环氧树脂交联网络中引入两端与DGEBA化学连接的PEG链段能避免微相分离结构的生成, 有利于提高DGEBA链段的应变松弛速率. 增加M_PE, 一方面能降低环氧树脂固化产物的玻璃化转变温度和室温下的刚度和拉伸强度, 增加韧性(包括冲击强度和拉伸韧性)、断裂应变和模量损耗因子; 另一方面也能提高固化产物在低温下的储存模量. 优化M_PE可制备出在中低温下同时具有优异的拉伸强度、模量、断裂应变和冲击性能的BATPE-DGEBA环氧树脂.