Influence of different glass fiber sizings on selected mechanical properties of PET/glass composites

The properties of fiber-reinforced plastics are considerably influenced by fiber-matrix interaction. The aim of this study was to investigate the influence of glass fiber surface treatments on the morphology of poly(ethylene terephthalate) (PET) and on selected mechanical properties of unidirectional PET/glass fiber composites. The materials used here were E-glass fibers treated with model sizings including aminosilane as a coupling agent and polyurethane and epoxy resin dispersions as film formers and PET as the matrix. For identification of the degree of crystallinity of the PET matrix, differential scanning calorimetry (DSC) was used. To study the influence of the different sizings on the mechanical properties, the following tests were performed: interlaminar and intralaminar shear tests and a transverse tensile test. Dynamic-mechanical analysis (DMA) was used to characterize the behavior of the composites under dynamical load. The DSC results show that the overall crystallinity and the melting behavior of the PET matrix were hardly influenced by the glass fiber surface treatments used. The various strength properties of the composites are influenced not only by the silane coupling agent, but also by the type of film former. With an epoxy resin dispersion, the mechanical properties were enhanced compared with a polyurethane dispersion. These results were confirmed by characterization of the composites by DMA.     

Seeded Stage III glass dissolution behavior of a statistically designed glass matrix

The dissolution rate of some glasses accelerates after prolonged time spent at a slow, residual dissolution rate. This phenomenon is referred to as Stage III behavior. The acceleration in glass dissolution rate linked to Stage III behavior is significant and may be the most impactful behavior to long-term performance of glass in a repository. This work is aimed at understanding the effect of glass composition on Stage III behavior to add a level of technical defensibility to glass disposal. To this end, a set of 24 glass compositions were statistically designed, where eight glass components (SiO₂, B₂O₃, Al₂O₃, CaO, Na₂O, SnO₂, ZrO₂, and Others) have been independently varied in order to study the individual effects of each glass component. These glasses have been subjected to static dissolution tests at 90°C in deionized water and then seeded with zeolite Na-P2 28 days into the testing to induce Stage III behavior. The response of the glasses to the zeolite seeds fell into four primary types: (1) no response to seeds; (2) an immediate linear sustained acceleration in the rate; (3) an immediate linear acceleration in the rate followed by a decrease; and (4) a progressive acceleration in the rate that is concurrent with the addition of the seeds. The main glass components observed to influence these behaviors were CaO, Al₂O₃, B₂O₃, and ZrO₂, where (1) CaO influenced which glasses showed a Stage III response to seeds (high CaO: types 2, 3, and 4) or did not respond to seeds (low CaO: type 1), (2) Al₂O₃ and B₂O₃ influenced which glasses showed a sustainable Stage III response (high Al₂O₃: types 2 and 4) versus transitory response (low Al₂O₃ and high B₂O₃: type 3), and (3) ZrO₂ concentration influenced whether glasses showed a linear (high ZrO₂: type 2) versus progressive (low ZrO₂: type 4) response to seeds.     

Swelling and glass transition relations for epoxy matrix material in humid environments

An experimental investigation has established coherent data sets describing effects of moisture absorption upon swelling and glass transition of an epoxy resin. Equilibrium moisture absorption levels and resultant swelling can be represented by power law functions of relative humidity and quantity of absorbed moisture, respectively. Depression of glass transition temperature is shown to be described by a relationship derived from free-volume theory.     

Effects of sizings on microscopic flow in resin transfer molding

Sizings significantly affect the processing and final performance characteristics of resin transfer molded (RTM) parts. Manufacturers often use sizings to enhance compatability between the resin and reinforcement and to assist processing. In particular, such coatings can affect the microscopic flow characteristics of resins during the infusion stages of the RTM process. To understand the mechanisms by which sizings affect preform wet-out and the extent of such effects, the influence of fiber sizings and fiber loadings on the flow of a vinyl-ester resin system, through axially aligned carbon fibers, have been measured. The results and analysis of the experiments reported herein form the basis for a phenomenological model that describes the effect of sizings on micro-flow in RTM. Furthermore, the work provides insight into the relationships among micro-flow, macro-flow, and preform infiltration. It is seen that sizings dramatically influence micro-impregnation and, for the flow configuration studied, radial micro-flow into fiber bundles was the rate limiting process for complete fiber bundle infusion.     

The use of urethane rubber/epoxide resin blends as matrix materials for glass and carbon fiber composites

We consider the effects of using urethane rubber/epoxide resin blends as matrices for unidirectional glass and carbon fiber and for balanced-weave glass fiber cloth composites. The mechanical properties of the unreinforced resin and various composites were measured for specimens with matrices containing up to 35 percent of urethane. The properties of the unreinforced resin show very marked changes between 30 and 35 percent of urethane due, it is believed, to the existence of discrete regions of urethane polymer throughout the matrix. The transverse properties of the unidirectional carbon fiber composites are significantly enhanced by the presence of 20 percent of urethane in the matrix without, apart from a decrease in the shear modulus, any marked change in other properties. This could prove useful in the applications of carbon fiber composites. Results for glass fiber materials are less dramatic, possibly because of poorer adhesion between the glass fiber and the urethane. If this is indeed the cause of the results, it should be possible to bring about an improvement for glass fiber composites by using fibers coated with a suitable coupling agent.     

Rheology of thermoplastic matrix short glass fiber composites

An experimental investigation of the processing of glass-fiber reinforced polypropylene is presented. Final fiber length distribution, chopped strand disgregation, matrix and composite rheological properties, die swelling, and surface morphology are analyzed. Strand disgregation is observed to increase with shear rate and fiber concentration and to decrease with the length of the die. Final fiber length distribution appears to be independent of die length but decreases with fiber concentration and shear rate. The viscosity and first normal coefficient functions show a linear dependence with shear rate and increases with fiber concentration. The extruded filament surface shows a minor roughness when the shear rate increases. The results of this experimental characterization give useful information for determining the influence of processing variables on the final properties of short fiber reinforced polypropylene and constitutes the first part of a more ambitious project that also includes the development of a modeling strategy of the processing behavior of short fiber composites.     

热固性碳纤维预浸料用环氧类基体树脂

综述了碳纤维预浸料用环氧树脂体系,介绍了国内外环氧树脂及其固化体系的发展现状;从碳纤维预浸料对基体树脂的要求,对环氧树脂固化体系的选择以及如何在树脂调配工艺上防止环氧树脂的爆聚等几个方面进行了详细的概述。     

碳纤维增强树脂基复合材料的应用研究

碳纤维增强树脂基复合材料以其优异的综合性能成为当今世界材料学科研究的重点。本文介绍了的碳纤维增强复合材料的性能，简述了增强机理、成型工艺及其应用领域和发展趋势。     

MFE乙烯基酯树脂在玻璃钢行业的应用

本文从国家建设部批准公布“建筑防腐蚀构造96J333(一)、(二)”中认为：“乙烯基酯树脂材料不但具有环氧树脂材料的优良的力学性能、不饱和聚酯树脂材料室温下简便成型的工艺性能,而且具有独特的耐腐蚀性能、耐温性能和耐久(抗紫外线)性以及华昌公司生产的MFE系列耐蚀乙烯基酯树脂、不饱和聚酯树脂、呋喃树脂及新型耐蚀涂料、自流平涂料等,作为高新技术产品纳入《建筑施工手册》,可以证明MFE系列耐蚀乙烯基酯树脂的应用,并且华昌公司生产的MFE乙烯基酯树脂以其优良的综合性能于1994年被国务院有关部委认定为国家级新产品。     

Swelling and dissolution in cleaning of whey protein gels

Fluid dynamic gauging was used to study swelling and dissolution, under alkaline conditions, of heat-induced gels prepared from solutions of β-lactoglobulin (βLg), a whey protein isolate and whey protein concentrate. Recent developments in the understanding of the cleaning behaviour of proteinaceous dairy foulant, obtained using heat-induced βLg gels, are summarised. The thickness-time profiles for βLg gels exhibited Fickian behaviour, whilst the whey protein-based systems showed linear swelling behaviour. The pH values at which the latter gels started to swell were significantly higher than those observed for βLg, while they all showed a pH/volume fraction threshold for dissolution. These differences in swelling and dissolution behaviour are related to the structure of the gels, i.e. fine stranded vs. particulate, and suggest that the key step in the alkaline dissolution of industrial dairy foulants is the conversion of particulate gels to the fine-stranded form.     

Effect of glass fiber surface treatment on the mechanical strength of glass fiber reinforced resin mineral composite for machine tool bed

With excellent vibration alleviating properties, resin mineral composite (RMC) has attracted special attention in the field of mechanical engineering. However, applications of RMC are restricted because of its limited mechanical strength. In this research, the glass fiber (GF) was added into RMC to increase its mechanical strength, and the effect of the length and mass fraction of GF on the mechanical strength of GF/RMC were investigated. Results showed that the compressive strength and flexural strength of RMC first increased and then decreased as the length and mass fraction of GF increased. In order to improve the interfacial bonding between GF and RMC, the GF was subsequently treated by ultrasonication, oxidation, and silanization. And three types of treated GF, i.e., ultrasonic treated GF (U‐GF), ultrasonic and oxidation treated GF (O‐GF), and ultrasonic, oxidation and silanization treated GF (S‐GF) were obtained. Among these three types of treated GF, the S‐GF exhibited superior reinforcement in RMC. In addition, the effect of oxidation parameters on the mechanical strength of S‐GF/RMC was investigated. In the case of sodium hydroxide oxidation, the optimum mechanical strength of S‐GF/RMC was achieved when the S‐GF was treated in 1.5 mol/L sodium hydroxide for 3 h at 40°C, in which the compressive strength and flexural strength of S‐GF/RMC increase by 17.5% and 20.8% compared to neat RMC, respectively. In the case of hydrogen nitrate oxidation, the best mechanical strength of S‐GF/RMC was achieved when the S‐GF was treated in 1.5 mol/L hydrogen nitrate for 5 h at 80°C, in which the compressive strength and flexural strength of S‐GF/RMC increased by 11.2% and 18.1% compared to neat RMC, respectively. POLYM. COMPOS., 38:1559–1570, 2017. © 2015 Society of Plastics Engineers     

Incorporation of epoxidized soybean oil as co‐matrix in epoxy resin toward developing plastisol/particulate toughened glass fiber composites

Epoxidized soybean oil was incorporated as a co‐matrix into an epoxy resin, and the hybrid resin system was used for preparing glass fiber‐reinforced composites. Effect of addition of poly(vinyl chloride) plastisol and selected particulate fillers (fly ash and wood flour) to epoxy/epoxidized soybean oil matrix on mechanical and water uptake properties of glass fiber‐reinforced composites were studied. Fourier transform infrared spectroscopy was used to reveal the curing state of these composites. It was observed that tensile strengths and moduli decreased with the inclusion of all additives. However, addition of poly(vinyl chloride) plastisol, fly ash, and wood flour particulate fillers showed significant increase in impact strengths compared with neat epoxy composite in a synergistic manner. Water uptake results of the composites were found to be in good agreement with ? OH peak intensities obtained from Fourier transform infrared spectroscopy. Finally, acousto‐ultrasonic nondestructive technique was successfully used to assess damage states and to relate stress wave factors with tensile strength properties of modified epoxy‐based glass fiber composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40586.     

An impact study of epoxy resin composites reinforced with glass fiber fabrics

The impact properties of epoxy resin composites reinforced with three types of fabrics which are welf-knitted structural fabrics (WKSF), three-dimensional fabrics (3D-3A & 3D-5A) and plain-weave structural fabrics (2D-2A) have been investigated. The results of experiments show that WKSF composite has total impact energy about 1.5 and 3.5 times those of 3D and 2D fabrics composite respectively. The ductility index of WKSF is about 2.2 times of those of 3D and 2D. WKSF composites are very ductile materials and can absorb much more impact energy than 3D and 2D composites. The pushed-out volume of WKSF composites after the impact test was calculated from the photographs and the results show that the volume of the pushed-out zone is proportional to impact energy.     

碳纤维增强树脂基复合材料的最新应用现状

介绍了碳纤维增强树脂基复合材料的性能特点,结合碳纤维增强树脂基复合材料的优异性能,讨论了其在新能源(风力发电、钻井采油和天然气储存)、汽车(外覆盖件、刹车片和涡轮增压)和航空航天(民用飞机、战略导弹)领域的最新应用。最后对碳纤维增强树脂基复合材料未来的发展方向进行了展望。     

Wear response of glass fiber and ceramic tile-reinforced hybrid epoxy matrix composites

Iranian Polymer Journal - This study presents the tribological behavior of epoxy matrix composites containing two different fillers. The composites contain fillers with different particle sizes...     

Synthesis and characterization of chlorinated soy oil based epoxy resin/glass fiber composites

Composites with good toughness properties were prepared from chemically modified soy epoxy resin and glass fiber without additional petroleum based toughening agent. Chlorinated soy epoxy (CSE) resin was prepared from soybean oil. The CSE was characterised by spectral, and titration method. The prepared CSE was blended with commercial epoxy resin in different ratios and cured at 85°C for 3 h, and post cured at 225°C for 2 h using m‐phenylene diamine (MPDA) as curing agent. The cure temperatures of epoxy/CSE/MPDA with different compositions were found to be in the range of (151.2–187.5°C). The composite laminates were fabricated using epoxy /CSE/MPDA‐glass fiber at different compositions. The mechanical properties such as tensile strength (248–299 MPa), tensile modulus (2.4–3.4 GPa), flexural strength (346–379 MPa), flexural modulus (6.3–7.8 GPa) and impact strength (29.7–34.2) were determined. The impact strength increased with the increase in the CSE content. The interlaminor fracture toughness (G_IC) values also increased from 0.6953 KJ/m² for neat epoxy resin to 0.9514 KJ/m² for 15%CSE epoxy‐modified system. Thermogravimetric studies reveal that the thermal stability of the neat epoxy resin was decreased by incorporation of CSE. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Adhesion improvement in glass fiber reinforced polyethylene composite via admicellar polymerization

Admicellar polymerization (polymerization of monomer solubilized in adsorbed surfactant bilayers) has been used to form a thin film of polyethylene onto the surface of milled glass fibers using sodium dodecyl sulfate as the surfactant. The decrease in ethylene pressure was used to follow the solubilization and adsolubilization processes as well as the reaction processes. An increase in initiator (Na₂S₂O₈) to surfactant ratio gave thicker and more uniform coatings of polymer onto the glass fiber surface according to SEM micrographs. Although a substantial amount of ethylene polymerized in solution according to the pressure drop, the decrease in pressure attributed to admicelle polymerization corresponded to the amount of polymer formed on the glass fiber, indicating little, if any, solution polymer deposited on the fibers. The admicellar‐treated glass fiber was used to make composites with high‐density polyethylene. The composites showed an increase in tensile and flexural strength over composites made from as‐received glass fiber, indicating an improvement in the fiber‐matrix adhesion of the admicellar‐treated glass fiber.     

醚化海藻酸钠-丙烯酸-聚乙烯醇高吸水树脂在环境介质中的溶胀行为

以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸铵-亚硫酸氢钠为引发剂,采用水溶液法合成了醚化海藻酸钠-丙烯酸-聚乙烯醇高吸水性树脂.考察比较了树脂在不同pH值缓冲溶液和盐溶液中的平衡含水率.结果表明,在酸性介质中,凝胶的溶胀过程为—COO^-的质子化过程控制,溶胀过程表现出non-Fickian动力学行为; 在碱性介质中,溶胀过程主要由溶剂扩散控制,表现出Fickian动力学行为,随着pH值升高,凝胶的平衡含水率升高; 在离子强度相近时,树脂在pH缓冲溶液中的溶胀率比在单价盐离子溶液中低,但比在二价盐溶液中高.对聚合物-溶剂的相互作用机理进行了探讨.     

树脂基纤维增强复合材料超高应变率拉伸研究

通过爆炸自由膨胀实验技术,采用特殊的薄环试样,对树脂基纤维增强复合材料在超高应变率(104/s)下进行了冲击拉伸实验研究。通过自由膨胀环实验,得到了一些芳纶纤维、玻璃纤维、碳纤维等增强的树脂基复合材料在超高压应变率下的冲击拉伸试验数据,在实验中应用了简便的应变片电测技术,并优化了装药和试样环的设计。为了验证实验数据,采用LY12cz铝合金进行了不同应变率下应力-应变拉伸性能的比较。通过树脂基复合材料爆炸自由膨胀环实验的分析,对实验技术中存在的问题提出了一些建议。研究表明,爆炸自由膨胀环拉伸技术是目前获得纤维增强复合材料超高应变率力学性能的1种相当有效的实验方法。