Physical,mechanical, and water absorption behavior of coir/glass fiber reinforced epoxy based hybrid composites

Fiber reinforced polymer composites has been used in a variety of application because of their many advantages such as relatively low cost of production, easy to fabricate, and superior strength compare to neat polymer resins. Reinforcement in polymer is either synthetic or natural. Synthetic fiber such as glass, carbon, etc. has high specific strength but their fields of application are limited due to higher cost of production. Recently there is an increase interest in natural composites which are made by reinforcement of natural fiber. In this connection, an investigation has been carried out to make better utilization of coconut coir fiber for making value added products. The objective of the present research work is to study the physical, mechanical, and water absorption behavior of coir/glass fiber reinforced epoxy based hybrid composites. The effect of fiber loading and length on mechanical properties like tensile strength, flexural strength, and hardness of composites is studied. The experimental results reveal that the maximum strength properties is observed for the composite with 10 wt% fiber loading at 15 mm length. The maximum flexural strength of 63 MPa is observed for composites with 10 wt% fiber loading at 15 mm fiber length. Similarly, the maximum hardness value of 21.3 Hv is obtained for composites with 10 wt% fiber loading at 20 mm fiber length. Also, the surface morphology of fractured surfaces after tensile testing is examined using scanning electron microscope (SEM). POLYM. COMPOS., 35:925–930, 2014. © 2013 Society of Plastics Engineers     

Pultruded fiber reinforced thermoplastic poly(methyl methacrylate) composites. Part II: Mechanical and thermal properties

A novel process has been developed to manufacture poly(methyl methacrylate) (PMMA) pultruded parts. The mechanical and dynamic mechanical properties, environmental effects, postformability of pultruded composites and properties of various fiber (glass, carbon and Kevlar 49 aramid fiber) reinforced PMMA composites have been studied. Results show that the mechanical and thermal properties (i.e. tensile strength, flexural strength and modulus, impact strength and HDT) increase with fiber content. Kevlar fiber/PMMA composites possess the highest impact strength and HDT, while carbon fiber/PMMA composites show the highest tensile strength, tensile and flexural modulus, and glass fiber/PMMA composites show the highest flexural strength. Experimental tensile strengths of all composites except carbon fiber/PMMA composites follow the rule of mixtures. The deviation of carbon fiber/PMMA composite is due to the fiber breakage during processing. Pultruded glass fiber reinforced PMMA composites exhibit good weather resistance. They can be postformed by thermoforming, and mechanical properties can be improved by postforming. The dynamic shear storage modulus (G′) of pultruded glass fiber reinforced PMMA composites increased with decreasing pulling rate, and G′ was higher than that of pultruded Nylon 6 and polyester composites.     

Glass fiber‐reinforced polyamide composites toughened with ABS and EPR‐g‐MA

A series of glass fiber‐reinforced rubber‐toughened nylon 6 composites was prepared. The mechanical properties and morphology of the composites toughened with ABS were investigated and compared with composites toughened with EPR‐g‐MA. A study of the mechanical properties showed that the balance of the impact strength and stiffness for both types of systems can be significantly improved by proper incorporation of glass fibers into toughened nylon 6. The differences between these two types of rubber‐toughened composites are significant at a high rubber content. However, the ductility of both composites toughened with rubber was significantly lower than that of blends without glass fiber. The relationships between rubber content, nylon 6 molecular weight, compatibilizer, processing, and mechanical properties are discussed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 484–497, 2001     

Pultruded fiber-reinforced poly(methyl methacrylate) composites. II. Static and dynamic mechanical properties,environmental effect,and postformability

This paper presents a novel process developed to manufacture poly(methyl methacrylate) (PMMA) pultruded composite. The mechanical, thermal, and dynamic mechanical properties, environmental effect, postformability of various fiber (glass, carbon, and Kevlar 49 aramid fiber) reinforced pultruded PMMA composites have been studied. Results show mechanical properties (i.e., tensile strength, specific tensile strength, tensile modulus, and specific flexural strength) and thermal properties (HDT) increase with fiber content. Kevlar fiber/PMMA composites possess the highest specific tensile strength and HDT, carbon fiber/PMMA composites show the highest tensile strength and tensile modulus, and glass fiber/PMMA composites show the highest specific flexural strength. Pultruded glass-fiber-reinforced PMMA composites exhibit good weather resistance. These composite materials can be postformed by thermoforming under pressure, and mechanical properties of postformed products can be improved. The dynamic shear storage and loss modulus (G′, G″) of pultruded glass-fiber-reinforced PMMA composites increased with decreasing pulling rate, and their shear storage moduli are higher than those of pultruded Nylon 6 and polyester composites.     

Mechanical properties of poly(styrene‐co‐acrylonitrile)‐modified epoxy resin/glass fiber composites

Poly(styrene‐co‐acylonitrile) was used to modify diglycedyl ether of bisphenol‐A type epoxy resin cured with diamino diphenyl sulfone and the modified epoxy resin was used as the matrix for fiber‐reinforced composites (FRPs) to get improved mechanical properties. E‐glass fiber was used as fiber reinforcement. The tensile, flexural, and impact properties of the blends and composites were investigated. The blends exhibited considerable improvement in mechanical properties. The scanning electron micrographs of the fractured surfaces of the blends and tensile fractured surfaces of the composites were also analyzed. The micrographs showed the influence of morphology on the properties of blends. Results showed that the mechanical properties of glass FRPs increased gradually upon fiber loading. Predictive models were applied using various equations to compare the mechanical data obtained theoretically and experimentally. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Performance improvement of glass-fiber-reinforced polystyrene composite using a surface modifier. II. Mechanical properties of composites

The mechanical properties of glass-fiber-reinforced polystyrene composites were investigated with the variation of glass fiber content, surface treatment conditions, and silane coupling agents. γ-MPS, GPS, and poly(γ-MPS-co-stvrene) were used for the surface modification of glass fiber. Mechanical properties of glass-fiber-reinforced polystyrene composites increased with increasing the content of glass fiber. Poly(γ-MPS-co-styrene) was superior to γ-MPS and GPS in promoting the interfacial adhesion of glass fiber-reinforced polystyrene composites. The mechanical properties of composites were maximum at a low copolymer concentration when the γ-MPS content in the copolymer was high and vice versa. © 1996 John Wiley & Sons, Inc.     

Mechanical properties of in-situ composites based on partially miscible blends of glass-filled polyetherimide and liquid crystalline polymers

The use of inorganic (glass) fiber reinforcement to enhance the mechanical properties and reduce the anisotropy of in situ composites based on blends of liquid crystalline polymers (LCPs) with polyetherimide (PEI) is discussed. It was found that the tensile and flexural moduli are increased and the anisotropy is reduced with increasing grass content (when compared at equivalent LCP weight fractions). The creep compliance of the PEI/LCP composites is reduced upon the addition of glass fibers. However, the disadvantage is that the processability worsens upon addition of glass fibers to the PEI/LCP in situ composites. The effect of adding glass reinforcement on the ultimate tensile strength is less clear, because the data do not show any consistent trend. Similarly, the elongation at break and toughness do not show any consistent improvement upon addition of glass reinforcement. Morphological studies show that there is considerable difference between the size and texture of the reinforcing glass fibers and LCP microfibrils.     

汽车内饰用PP/黄麻纤维复合材料力学性能

采用转矩流变仪混合造粒,通过注射成型方法制备了聚丙烯(PP)/黄麻纤维复合材料,研究了对纤维表面进行处理的NaOH浓度、纤维含量和相容剂的含量对PP/黄麻纤维复合材料力学性能的影响,采用扫描电镜对纤维表面及复合材料的断面形貌进行分析。结果表明:黄麻纤维经过碱处理后PP/黄麻纤维复合材料的力学性能优于纤维未处理的复合材料的力学性能,随着NaOH浓度的提高,PP/黄麻纤维复合材料的拉伸强度和冲击强度增加,在NaOH浓度为16%时,其拉伸强度和冲击强度最佳;其弯曲强度随着NaOH浓度的提高先增加而后下降,在8%浓度时,弯曲强度最大。随着纤维含量的提高,PP/黄麻纤维复合材料的拉伸强度和弯曲强度先增加后下降,在纤维含量达到20%时,PP/黄麻纤维合材料的拉伸强度和弯曲强度达到最大。随着纤维含量的提高,PP/黄麻纤维复合材料的冲击强度降低。相容剂的加入使得PP/黄麻纤维复合材料的拉伸强度和弯曲强度明显增加。     

聚丙烯/麦秸秆木塑复合材料的力学性能

采用转矩流变仪混合造粒,通过注射成型方法制备了聚丙烯(PP)/麦秸秆木塑复合材料,研究了NaOH浓度、增容剂的含量和麦秸秆含量对PP/麦秸秆木塑复合材料力学性能的影响,采用扫描电子显微镜对麦秸秆表面及复合材料的断面形貌进行分析。结果表明:8%NaOH溶液处理麦秸秆时,PP/麦秸秆木塑复合材料的拉伸强度、弯曲强度和冲击强度达到最大;马来酸酐接枝PP增容剂的加入使得麦秸秆与PP的界面相容性提高,复合材料的力学性能增加;在一定范围内麦秸秆的添加降低了PP材料的拉伸强度和冲击强度,而提高了其弯曲强度,并且PP/麦秸秆复合材料的弯曲强度随着麦秸秆含量的增加而增加,在麦秸秆含量为30%时弯曲强度达到最大值为43.4 MPa。     

Characterization of Short Glass Fiber–Reinforced Castor Oil–Based Polyurethane Polystyrene Interpenetrating Networks

ABSTRACT

Chopped strand glass fiber–reinforced particle-filled castor oil–based polyurethane polystyrene composites with varying weight fractions of glass fibers were investigated for morphology, tensile strength, and absorption of various chemicals. The short glass fiber fraction was varied from 1% to 16% (by wt.) of the total composite system. The tensile strength of these composites was much higher than that of unfilled IPNs for the same concentration of polystyrene. The tensile strength of the IPN composites increases with the increase in fiber content up to a fiber percentage of 9%. After that, there is a sharp decline in tensile modulus as well as elongation at break. The chemical absorption showed an increase with increasing glass fiber content.     

阻燃PA66复合材料翘曲性能研究

对比研究了无玻璃纤维、普通圆形玻璃纤维、扁平玻璃纤维对溴系阻燃聚酰胺66(PA66)复合材料的翘曲性能影响,分别从力学性能、结晶性能、收缩率和横向/纵向收缩率比等因素阐述复合材料翘曲性能.结果表明,相同阻燃剂含量条件下,不加玻璃纤维复合材料的结晶度最高,横向收缩率与纵向收缩率最大,但横向/纵向收缩率比最小,复合材料翘曲...     

Effects of alkalization and fiber loading on the mechanical properties and morphology of bamboo fiber composites. II. Resol matrix

Resol resin composites reinforced with alkali‐treated bamboo strips were fabricated with a hand‐lay‐up technique. This study was aimed at the evaluation of the influence of the caustic concentration on the mechanical properties of bamboo‐strip‐reinforced resol composites with a constant 50% loading of the reinforcement. The treatment of bamboo fiber in a solution of sodium hydroxide with increasing concentration percentages resulted in more and more rigid composites; as a result, the strength and modulus values exhibited improvements. The maximum improvement in the properties was possibly achieved with 20% caustic treated reinforcements. An infrared study indicated the formation of aryl alkyl ether with ? OH groups of cellulose and methylol groups of resol. Beyond 20%, there was degradation in all the strength properties due to the failure of the mechanical properties of the reinforcement itself. A correlation was found to exist between the mechanical properties and the morphology that developed. Another set of composites with variable loadings of 20% alkali treated fiber (40, 50, and 60%) was fabricated, and a 60% fiber loading showed the best mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Studies on mechanical characterization and water resistance of glass fiber/thermoplastic polymer bionanocomposites

This experimental work is aimed at studying the performance of rice husk flour/glass fiber reinforced high density polyethylene hybrid nanocomposites. To meet this objective, the nanoclay was compounded with high density polyethylene (HDPE), rice husk flour (RF), glass fiber, and coupling agent in an internal mixer; then, the samples were fabricated by injection molding. The concentration was varied from 0 to 6 per hundred compounds for nanoclay and from 0 to 15% for glass fiber, individually. The amount of coupling agent was fixed at 2% for all formulations. The morphology, water absorption, thickness swelling, and mechanical properties of nanocomposites were evaluated as a function of nanoclay and glass fiber contents. The results indicated that both modulus and strength were improved when glass fibers were added to the composites system but impact strength and moisture absorption further decreased with the increase of glass fiber content. The morphology of the nanocomposites has been examined by using X‐ray diffraction. The morphological findings revealed that the nanocomposites formed were intercalated. The mechanical analysis showed that the biggest improvement of the tensile and flexural modulus and strengths can be achieved for the nanoclay loading at 4 per hundred compounds. However, further increasing of the loading of nanoclay resulted in a decrease of impact strength. Finally, it was found that addition of nanoclay reduced the water absorption and thickness swelling of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The unidirectional glass fiber reinforced furfuryl alcohol for pultrusion. II. Correlation of processing parameters for optimizing the process

Unidirectional glass fiber reinforced furfuryl alcohol (FA) composites have been prepared by the pultrusion processes. The optimum processing parameters of the glass fiber reinforced FA composites by pultrusion has been studied. The effects of the optimum processing parameters on the properties (flexural strength, flexural modulus, notched Izod impact strength, glass transition temperature (T_g), dynamic shear storage modulus (E'), shrinkage ratio, and roughness) investigated including die temperature, pulling rate, postcure temperature and time, and filler type and content. Results show that the pultruded composites possessed various optimum pulling rates at different die temperatures. On the basis of the DSC diagram, the swelling ratio and the mechanical properties of pultruded composites, the optimum die temperature can be determined. The mechanical properties and T_g increase at a suitable postcure temperature and time. Furthermore, the properties which decrease due to the degradation of pultruded composites for a long postcure time will be discussed. The mechanical properties of pultruded composites reach a maximum value at various filler content corresponding to the talc and calcium carbonate, respectively, and then decreased. When the fillers are added to the pultruded glass fiber reinforced FA composites, the shrinkage ratio of composites become smaller, and the surface of composites became smooth. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Corn oil‐based composites reinforced with continuous glass fibers: Fabrication and properties

Novel thermosetting composites have been successfully developed using glass fibers to reinforce regular corn oil (COR) and conjugated corn oil (CCOR) resins prepared by cationic copolymerization with styrene (ST) and divinylbenzene (DVB). The dependence of morphology and physical properties of the composites on the contents of glass fibers and DVB was determined by scanning electron microscopy, dynamic mechanical analysis, thermogravimetric analysis and tensile testing. The glass fiber loading and polymer matrix composition play an important role in improving the mechanical properties and thermal stability of the resulting composites. As the glass fiber content increases from 0 to 45 wt %, the COR‐based composites show an increase in Young's modulus from 4.1 to 874 MPa and tensile strength from 1.7 to 8.4 MPa. Furthermore, the composites exhibit good damping properties and are suitable for applications where reduction of both unwanted noise and vibration is important. Compared with the composites from COR, the CCOR‐based composites exhibit slightly higher thermal stabilities and mechanical properties, due to higher reactivity of CCOR with comonomers. Increasing the DVB content improves the crosslink density of the polymer matrix, leading to a significant improvement in the thermal stabilities and mechanical properties of the resulting composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3345–3353, 2006     

Mechanical properties of hybrid structural composites reinforced with nanosilica

Epoxy‐based hybrid structural composites reinforced with 14 nm spherical silica particles were investigated for mechanical properties as a function of nanosilica loading fractions. Composites were fabricated using continuous glass or carbon fiber of unidirectional architecture and nanosilica dispersed epoxy, through resin film infusion process. Uniform dispersion of nanoparticles in resin matrix was ensured by an optimized ultrasound‐assisted process. Although resin viscosity marginally reduces in the presence of nanosilica enabling a better control in composite manufacturing process, glass transition temperature of epoxy remained unaffected at low weight fractions. Compressive strength of hybrid glass or carbon fiber/epoxy composites showed more than 30–35% increase with nanosilica at a concentration as low as 0.2 wt%. Tensile and compressive properties of hybrid composites in transverse direction to the reinforcement remained unaffected. POLYM. COMPOS. 37:1216–1222, 2016. © 2014 Society of Plastics Engineers     

玻璃纤维布增强EP/PPO复合材料性能及应用

利用材料试验机、扫描电镜、高频微波仪及差示扫描量热仪研究了玻璃纤维布增强环氧树脂(EP)/聚苯醚(PPO)复合材料的弯曲性能、相态、介电性能和耐热性。结果表明,树脂含量对EP/PPO复合材料的弯曲强度和介电性能影响很大,在树脂质量分数约为40%时,复合材料的弯曲强度最大;当树脂质量分数大于30%时,介电常数的理论预测值与实验结果基本符合;硅烷偶联剂KH-550处理玻璃纤维布制得复合材料的弯曲性能较优;玻璃纤维布增强EP/PPO复合材料的热性能比纯EP/PPO树脂的热稳定性好。     

Study on mechanical properties of powder impregnated glass fiber reinforced poly(phenylene sulphide) by injection molding at various temperatures

The prepreg of continuous glass fiber reinforced poly(phenylene sulphide) (PPS) was prepared using the powder impregnation technique and cut into the pellets, in which the length of glass fibers was the same as the pellets. After injection molding, the mechanical properties were tested and the effects of the pellet length, fiber content, and thermal treatment on the mechanical properties at different temperatures were studied. It is found that the tensile strength and flexural strength of 6‐mm pellet sample are slightly higher than that of 3‐ and 12‐mm pellet samples. The tensile strength, flexural strength, and modulus decrease significantly with increasing the temperature. The notched Izod impact strength at 85ºC is higher than both at 25ºC and 205ºC. At 205ºC, the glass fiber reinforced PPS composites can still keep better mechanical properties. When the fiber content ranges from 0 to 50%, the mechanical properties increase with increasing the fiber contents at different temperatures, except the notched Izod impact strength do not further increase at 145 and 205ºC with raising the fiber content from 40 to 50%. Thermal treatment could improve the mechanical properties of the composites at higher serving temperature. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Mechanical characterization and fractography of glass fiber/polyamide (PA6) composites

The mechanical properties of the glass fiber reinforced Polyamide (PA6) composites made by prepreg tapes and commingled yarns were studied by in‐plane compression, short‐beam shear, and flexural tests. The composites were fabricated with different fiber volume contents (prepregs—47%, 55%, 60%, and commingled—48%, 48%, 49%, respectively) by using vacuum consolidation technique. To evaluate laminate quality in terms of fiber wet‐out at filament level, homogeneity of fiber/matrix distribution, and matrix/fiber bonding standard microscopic methods like optical microscopy and scanning electron microscopy (SEM) were used. Both commingled and prepreg glass fiber/PA6 composites (with V_f ∼ 48%) give mechanical properties such as compression strength (530–570 MPa), inter‐laminar shear strength (70–80 MPa), and transverse strength (80–90 MPa). By increasing small percentage in the fiber content show significant rise in compression strength, slight decrease in the ILSS and transverse strengths, whereas semipreg give very poor properties with the slight increase in fiber content. Overall comparison of mechanical properties indicates commingled glass fiber/PA6 composite shows much better performance compared with prepregs due to uniform distribution of fiber and matrix, better melt‐impregnation while processing, perfect alignment of glass fibers in the composite. This study proves again that the presence of voids and poor interface bonding between matrix/fiber leads to decrease in the mechanical properties. Fractographic characterization of post‐failure surfaces reveals information about the cause and sequence of failure. POLYM. COMPOS., 36:834–853, 2015. © 2014 Society of Plastics Engineers     

Fabrication and characterization of functionally graded nanoclay/glass fiber/epoxy hybrid nanocomposite laminates

In this work, hardness, tensile, impact, bearing strength and water absorption tests were performed to study the mechanical properties of stepwise graded and non-graded hybrid nanocomposites. Three different stepwise graded nanocomposites and one non-graded (homogeneous) nanocomposite with the same geometry and total nanoclay content of 10 wt% were designed and prepared. Moreover, one neat glass fiber laminate was manufactured. The results of the tests indicated that addition of the graded and non-graded nanoclay improves hardness over neat glass fiber reinforcement. The maximum increase in hardness of about 53% over neat specimen is obtained for specimens that have the highest weight percentage (2 wt%) of the clay nanoparticles on its surface (S-specimen and the side of F-specimen that reinforced with 2 wt% nanoclay). The gradation process results in an increase in hardness of about 11% compared with non-graded (homogeneous) specimen. In addition, an improvement of 11.9% in strain-to-failure is achieved with specimen having greatest amount of nanoclay in the middle over neat glass fiber/epoxy composite. The other nanoclay-filled glass fiber composites have strain-to-failure close to neat glass fiber/epoxy. The addition of nanoclay reinforcement has insignificant effect on ultimate tensile strength, tensile modulus, water absorption, bearing strength and impact strength compared with neat glass fiber/epoxy.