Improvement of the interfacial adhesion between PBO fibers and PPESK matrices using plasma‐induced coating

This work deals with the plasma‐induced coating process on the surface of PBO fibers to obtain a strong interfacial adhesion between the poly(p‐phenylene benzobisoxazole) (PBO) fibers and the poly(phthalazinone ether sulfone ketone) (PPESK) matrices. The process consisted of four steps: (a) plasma preactivation of PBO fibers; (b) immersion in an epoxy resin solution; (c) drying and then soaking with the PPESK solution; (d) shaped by compression molding technique. The orthogonal experiments used in this study enable the determination of the significant experimental parameters that influence efficiency of the process by comparing the values of ILSS. The order of their influences was the concentration > power > treating time > treating pressure. The results of the interlaminar shear strength (ILSS) and water absorption showed that the ILSS of the composite increased by 56.5% after coating, meanwhile the water absorption declined to 0.32%. The changes of the surface chemical composition, the surface morphology, and the surface free energy of fibers were studied by FTIR spectroscopy, atomic force microscope (AFM), and dynamic contact angle analysis (DCAA), respectively. Fracture mechanism of the composite was examined by scanning electron microscope (SEM). The results indicated that plasma‐induced coating process was an efficient method to enhance the interfacial adhesion of PBO fibers and PPESK matrices. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Improvement of the interfacial shear strength of poly(p‐phenylene benzobisoxazole) fiber/epoxy resin composite via a novel surface coating agent

Poly(p‐phenylene benzobisoxazole) (PBO) fiber with a smooth surface exhibits limited interfacial interaction with resin matrix. One of the effective strategies to improve the adhesion between the fiber and resin matrix is through surface modification of the fiber. In this study, we have proposed a novel surface treatment agent based on phosphoester cross‐linked castor oil (PCCO) for effective surface treatment of PBO fibers. The surface treatment agent was prepared by a simple cross‐linking reaction between hydroxy phosphorylated castor oil (PCO) and epoxy resin, with alcohol as the solvent at 65°C. Once the PBO fiber was treated with this agent, the interfacial adhesion between the PBO fiber and the epoxy resin could then be improved. Systematic analyses suggest that the surface treatment with (PCO + epoxy)/alcohol solution improves the interaction of the PBO fiber with the epoxy resin matrix. The PCCO coated onto the surface of PBO fiber acts as a coupling agent, improving the interfacial shear strength (IFSS) of the PBO fiber/epoxy resin composite. Results indicate a 156% increase in IFSS without compromising the mechanical properties of the fiber. POLYM. COMPOS., 37:1198–1205, 2016. © 2014 Society of Plastics Engineers     

Properties and microstructures of epoxy resin/TiO2 and SiO2 hybrids

Epoxy resin/TiO₂ and epoxy resin/SiO₂ hybrids were prepared by different procedures, and their mechanical properties were correlated to their microstructures, as indicated by small‐angle X‐ray scattering (SAXS) measurements. Epoxy resin/TiO₂ hybrids were prepared by mixing the epoxy resin (EP828) with N‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane (S320) in acetone, and then titanium‐n‐butoxide (TnBU) was added. In addition, epoxy/SiO₂ hybrids were prepared by mixing EP828 with a curing agent, a diamino heterocyclic compound (B002) in acetone, and an organo silica sol (silica nanoparticles dispersed in methylethylketone) was added. In the EP828/S320/TiO₂ hybrid systems, the TiO₂ component was attached to both of the chain ends of the epoxy matrix, hence leading to the formation of inorganic domains via the covalent bonds. SAXS profiles of these hybrids showed peaks at q = 2.3 nm^?1, caused by interference between the domains. The storage modulus increased with increasing TiO₂ content above the T_g, owing to the strong interactions between TiO₂ and the epoxy matrix. The tanδ peak position did not change, although the intensity decreased with increasing TiO₂ content. The SAXS profiles of the EP828/B002/SiO₂ hybrids were very different to those of the corresponding EP828/S320/TiO₂ hybrids, and indicated that SiO₂ particles with rough surfaces were randomly dispersed in the epoxy matrix. The storage moduli of the EP828/B002/SiO₂ hybrid systems increased only slightly with SiO₂ content, because of the weak interactions. These mechanical properties are well explained by the microstructures derived from the SAXS profiles. Copyright © 2004 Society of Chemical Industry     

Improvement of the mechanical properties of an ultrahigh molecular weight polyethylene fiber/epoxy composite by corona‐discharge treatment

The interfacial shear strength of an ultrahigh molecular weight (UHMW) polyethylene (PE) fiber/epoxy‐resin system was greatly improved by the corona‐discharge treatment of the fiber. The UHMW PE‐fiber/epoxy‐resin composite was prepared with corona‐discharge‐treated UHMW PE fiber. The mechanical properties of the composite sheet were determined by tensile testing. The tensile strength of the composite was also very much improved. However, the tensile strength of the composite was about one‐half of the theoretical strength. This result was due to the molecular degradation of the PE‐fiber surface caused by surface modification. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1162–1168, 2001     

碳纤维/环氧树脂复合材料的改性及改性机理

介绍了碳纤维/环氧树脂复合材料中碳纤维的增强机理.综述了纳米材料、聚合物对碳纤维/环氧树脂复合材料的改性进展,并总结了相应的改性机理.探索新型柔和的碳纤维表面处理技术以及对碳纤维表面接枝将是碳纤维/环氧树脂复合材料改性的发展方向.     

无机复合涂层对碳纤维性能的影响

采用溶胶-浸渍法在碳纤维表面制备了二氧化钛-二氧化硅复合涂层。考察了钛溶胶与硅溶胶体积比、浸渍方式、浸渍次数对涂层的影响。利用X射线衍射（XRD）、扫描电镜（SEM）和透射电镜（TEM）分析了涂层的相组成及形貌。通过静态等温氧化实验考察了复合涂层碳纤维的抗氧化性能。结果表明：钛溶胶与硅溶胶体积比为15∶1条件下采用真空超声浸渍3次,制备的复合涂层均匀、完整、致密,与碳纤维表面结合良好,涂层抗氧化性能好,涂层二氧化钛为锐钛矿型、二氧化硅为无定型。将复合涂层碳纤维在400 ℃连续氧化15 h,其质量损失率仅为5.91%。     

Temperature effect on interfacial bonding property of single‐carbon fiber/epoxy resin composite

The changes in interfacial fracture energy of three kinds of commercially sized carbon fiber (CF)/epoxy resin composites in the range from ambient temperature to 130°C were investigated using the single‐fiber fragmentation test to evaluate the heat resistance of the interphase. The effects of CF sizing on the interfacial bonding property were studied using desized CF/epoxy resin composites. Thermogravimetric analysis and differential scanning calorimetry of the combination of sizing and matrix were employed to investigate the role of sizing on the variations in the fiber/matrix interfacial property under elevated temperature. The interfacial fracture energy values of all the studied CF composites were found to decrease quickly during the initial stage of temperature rise and drop gradually at higher temperature. At elevated temperature, the desized CF composites had higher heat resistance than the corresponding sized fiber composites. The differences in the interfacial heat resistance among the three kinds of CF composites and the difference in the interfacial thermal stability between the sized and the desized fiber composites were related to different glass transition temperatures of the interphases. The interaction between sizing and the matrix and the chain motion of the crosslink structure of the interphase has been suggested to determine the interfacial heat resistance. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Potency of commercial TiO2‐P25 nanoparticles to form stainless steel protective coating

This research reports for the first time the surface coating of steel samples with commercial nanoparticles of TiO₂. Aiming to improve the substrate corrosion behavior, a stable suspension containing TiO₂‐P25 nanoparticles and polyvinyl alcohol in the water was prepared and the coating was applied on the surface of the substrate via dip‐coating. Heat treatment led to the formation of strong connection between the substrate and the coating film. Scanning electron microscopy and scanning probe microscopy were utilized to scrutinize the samples in terms of topography and microstructure. In addition, the samples corrosion behavior was investigated through Tafel polarization and impedance spectroscopy. The results showed that one‐step of sample dip‐coating in sol or heat treatment at 600°C cannot provide for desirable and appropriate physical circumstances in the thin film. The applied thin film showed the highest corrosion behavior improvement when the sample was coated with two or three films and the heat treatment was carried out at 400°C. In this respect, according to the Tafel curves, the applied coating efficiency was measured to be approximately 90%. The electrochemical impedance spectroscopy results indicated that the reference sample was single‐time constant and the coated sample was double‐time constant. Applying the coating increased impedance, reduced the capacitive element, and diminished the resistance area. All three mentioned factors contributed to the enhancement of corrosion behavior.     

碳纤维增强环氧树脂基复合材料的性能研究

研究了WBS-3环氧树脂固化体系的反应特性,分析了该固化体系浇铸体的性能;并以碳纤维(T-700S)为增强材料,采用手糊成型螺栓加压工艺制备了WBS-3/T-700S复合材料,研究了复合材料的常温力学性能、高温力学性能、水煮后力学性能和动态力学性能,并对弯曲断面进行分析。研究结果表明,WBS-3树脂基体黏度低、适用期长且韧性好,适合于手糊成型、缠绕成型等低成本制造工艺;由此制得的WBS-3/T-700S复合材料具有优良的力学性能和耐高温性能,其弯曲强度为1434MPa,拉伸强度为1972MPa,剪切强度为76.1MPa,玻璃化温度(Tg)超过210℃;该WBS-3/T-700S复合材料具有很好的界面粘接性(树脂对纤维的浸润性良好)、较低的空隙率且纤维分布均匀。     

石棉纤维对环氧基耐烧蚀涂料性能影响研究

论述了烧蚀涂料的功能和烧蚀机理。研究了在以环氧为基体材料的烧蚀涂料中,石棉纤维的各种状态（种类,粒径,含量,纯度以及处理工艺）对烧蚀材料的耐烧蚀性能和机械性能的影响。     

Preparation of emulsion‐type thermotolerant sizing agent for carbon fiber and the interfacial properties of carbon fiber/epoxy resin composite

A modified resin was synthesized through the reaction between dodecylamine and tetraglycidyldiaminodiphenylmethane (TGDDM), which was used as the film former of sizing agent for carbon fiber (CF). The sizing agents were prepared through phase inversion emulsification method. Fourier transform infrared spectroscopy (FTIR) was utilized to analyze the modified resin. Particle sizes of the sizing agents were tested to evaluate their stabilities. Differential scanning calorimetry (DSC) results demonstrated that the glass transition temperature (T_g) of the modified TGDDM is much higher than the T_g of the cured epoxy resin E‐44. The influences of the sizing treatment on CF were investigated by abrasion resistance, fluffs, and stiffness tests. The maximum abrasion resistance increased by 172.8%, compared with the abrasion resistance of the desized CF. Interlaminar shear strength (ILSS) results of the CF/TGDDM composites indicated that the interfacial adhesion between CF and matrix resin was greatly improved after CF was sized. The maximum ILSS value could obtain a 29.16% improvement, compared with the ILSS of the desized CF composite. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41882.     

环氧/碳纤维复合材料性能研究

本文主要分析了碳纤维帘子布复合材料的性能,并与T300单向碳纤维复合材料性能进行对比。结果表明,碳纤维帘子布复合材料性能低于T300单向碳纤维复合材料性能。     

超声辅助分散制备纳米TiO2/环氧复合材料

采用大功率超声设备将纳米TiO2粒子分散到环氧树脂（EP）中制得复合材料。通过TEM分析了纳米粒子在EP中的分布形态并测试了复合材料的弯曲强度和冲击强度。考察了超声作用周期、纳米粒子表面改性工艺及粒子含量对复合材料微观结构和性能的影响。结果表明,经KH-550表面改性的纳米粒子质量分数为3％时,采用超声振荡30s／停顿30s、反复作用10次的超声分散工艺得到的复合材料的性能最好。     

Improved interfacial adhesion in carbon fiber/epoxy composites through a waterborne epoxy resin sizing agent

A series of self‐emulsified waterborne epoxy resin (WEP) emulsions were used as surface sizing for carbon fibers (CFs) to improve the interfacial adhesion between the CF and epoxy matrix. In this work, the hydrogenated bisphenol‐A epoxy resin (HBPAE) was modified by polyethylene glycol (PEG) with molecular weights of 400, 800, 1000, 1500, 2000, 4000, and 6000 g/mol. The properties of the WEP emulsion were examined by Fourier transform infrared spectroscopy, dynamic light scattering, and transmission electron microscopy. The surface characteristics of sized CFs were evaluated using scanning electron microscopy, atomic force microscopy, and X‐ray photoelectron spectroscopy. Afterwards, CF/EP composites were prepared and their fracture surface and interlaminar shear strength (ILSS) were examined. The results indicated that PEG2000 modified HBPAE sizing had the optimum emulsion stability and film‐forming ability. Meanwhile, the results also demonstrated that a continuous and uniform sizing layer was formed on the surface of CFs and the surface sizing was excellent in improving the chemical activity of CFs. Compared with unsized CFs, the O1s/C1s composition ratio was observed to increase from 11.51% to 33.17% and the ILSS of CF/EP composites increased from 81.2 to 89.7 MPa, exhibiting better mechanical property than that of commercial Takemoto S64 sized CFs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44757.     

二氧化钛纳米管稳定Pickering乳液制备PS/TiO2纳米管复合微球

利用γ-甲基丙烯酰氧基丙基三甲氧基硅烷（KH-570）,对水热法制备的TiO₂纳米管进行了表面改性,并用改性的纳米管为稳定剂,采用Pickering乳液聚合法制备了聚苯乙烯/TiO₂纳米管复合微球。采用红外光谱（IR）、光学显微镜、高分辨透射电镜（HRTEM）、高分辨扫描电子显微镜（FESEM）、X射线光电子能谱（XPS）等分析手段,对改性前后TiO₂纳米管以及复合微球的结构和形貌进行了表征,用三相接触角仪测试并优化了TiO₂纳米管的表面润湿性。研究结果表明,当m_KH-570/m_TiO2=15%时,改性TiO₂纳米管表面润湿性最佳,能很好地稳定Pickering乳液聚合,聚合后可以得到壳层为致密均匀TiO₂纳米管,核为聚苯乙烯的复合微球。     

膨胀石墨／二氧化钛复合材料的制备与性能研究

本文主要研究了膨胀石墨／二氧化钛复合材料的制备,采用直接膨化的膨胀石墨与钛酸丁酯的醇溶液混合法制备膨胀石墨／二氧化钛复合材料,并分析了膨胀石墨／二氧化钛复合材料的物理性能,以甲基橙溶液的光催化降解反应为探针反应,评价了该复合材料的催化性能。     

Nonisothermal crystallization kinetics of flame‐sprayed polyamide 1010/nano‐ZrO2 composite coatings

Polyamide1010 (PA1010) and its composite with nanometer‐sized zirconia (PA1010/nano‐ZrO₂) coatings were deposited using a flame spray process. The kinetics of nonisothermal crystallization of PA1010/nano‐ZrO₂ composite coatings was investigated by differential scanning calorimetry (DSC) at various cooling rates. Several different analysis methods were used to describe the process of nonisothermal crystallization. The results showed that the modified Avrami equation and Mo's treatment could describe the nonisothermal crystallization of the composite coatings very well. The nano‐ZrO₂ particles have a remarkable heterogeneous nucleation effect in the PA1010 matrix. The values of halftime and Z_c showed that the crystallization rate increased with increasing cooling rates for both PA1010 and PA1010/nano‐ZrO₂ composite coating, but the crystallization rate of PA1010/nano‐ZrO₂ composite coating was faster than that of PA1010 at given cooling rate. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis of conducting polyaniline/TiO2 composite nanofibres by one‐step in situ polymerization method

Conducting polyaniline (PANI)/titanium dioxide (TiO₂) composite nanofibres with an average diameter of 80–100 nm were prepared by one‐step in situ polymerization method in the presence of anatase nano‐TiO₂ particles, and were characterized via Fourier‐transform infrared spectra, UV/vis spectra, wide‐angle X‐ray diffraction, thermogravimetric analysis, and transmission electron microscopy, as well as conductivity and cyclic voltammetry. The formation mechanism of PANI/TiO₂ composite nanofibres was also discussed. This composite contained ～ 65% conducting PANI by mass, with a conductivity of 1.42 S cm^?1 at 25°C, and the conductivity of control PANI was 2.4 S cm^?1 at 25°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

蒙脱石/TiO2复合材料制备及其光催化性能研究

以蒙脱土和钛酸丁酯为原料,采用溶胶凝胶法制备出蒙脱石/TiO2复合材料,利用XRD、SEM、光催化亚甲基蓝溶液对其物相组成、晶体结构、微观结构和光催化性能进行了研究.结果表明:TiO2以锐钛矿相分布于蒙脱石的层间域和表面,并使蒙脱石d001有不同程度的增大.蒙脱石/TiO2复合材料的加入量和Ti/蒙脱石比值、亚甲基蓝溶液的初始质量浓度对蒙脱石/TiO2复合材料的吸附和光催化效率均有影响.