Bamboo Fiber Composites Research Articles

An experimental effort on the impact of hot press forming process parameters on tensile, flexural & impact properties of bamboo fiber composites with the help of Taguchi experimental design

In the existent scenario of alarmingly accrescent demography of the universe, the pretensions of biodegradable green composites made from natural fibers are at their summit point due to their superior properties such as renewable character, low weight, low density, cost effectiveness, comparable specific strength, CO2 sequestration, admissible mechanical, acoustic & thermal insulation properties which also able to rendition themselves as a brawny & trade alternative to the petroleum based composite materials in various industrial & other applications. Inspite of their biodegradability & eco-friendly behaviour, the most influential factors that control the properties of the green composites are processing conditions, methodology, fiber/matrix adhesion & moisture resistivity of natural fibers nevertheless proper control of these factors can make the manifested composites more proficient & lithesome to different kinds of applications. Henceforth one endeavour is taken in this ploy to amplify the mechanical properties of bamboo fiber composites by optimizing the hot press forming process parameters such as temperature, pressure, pre-heat time, heating time & cooling rate with the help of Taguchi L16orthogonal array experimental design. By applying the analysis of the signal-to-noise ratio (S/N ratio) the optimum combination of process parameters has been acquired. Bring to Bear of analysis of variance (ANOVA) ascertained the importance of the levels on process parameters. Put Forth of regression analysis were mathematically modelled the metamorphism of tensile, flexural & impact properties with process parameters. In Fine, the presented models are also corroborated by a set of confirmation test.

Experimental Investigation and Analysis of Mercerized and Citric Acid Surface Treated Bamboo Fiber Reinforced Composite

Mercerization or NaOH fiber surface treatment is one of the most popular surface treatment processes to make the natural fibers such as bamboo fibers compatible for use as reinforcing material in composites. But NaOH being a chemical is hazardous and polluting to the nature. This paper explores the possibility of use of naturally derived citric acid for bamboo fiber surface treatment and its comparison with NaOH treated Bamboo Fiber Composites. Untreated, 2.5 wt% NaOH treated and 5 wt% citric acid treated Bamboo Fiber Composites with 5 wt% fiber content were developed by Hand Lay process. Bamboo mats made of bamboo slivers were used as reinforcing material. Mechanical and physical characterization was done to compare the effects of NaOH and citric acid bamboo fiber surface treatment on mechanical and physical properties of Bamboo Fiber Composite. The experiment data reveals that the tensile and flexural strength was found to be highest for citric acid and NaOH treated Bamboo Fiber Composite respectively. Water absorption tendency was found more than the NaOH treated Bamboo Fiber Composites. SEM micrographs used to analyze the morphology of fracture surface of tensile test specimens confirm improvement in fiber-matrix interface bonding due to surface treatment of bamboo fibers.

CaCO3 in situ treated bamboo pulp fiber reinforced composites obtained by vacuum-assisted resin infusion

The aim of this study is to investigate the properties of CaCO3 in situ treated bamboo pulp fiber (BPF) composites that have been filled with epoxy resin by means of vacuum-assisted resin infusion (VARI). Un-treated and treated BPF were processed at a pressure of 0.24 MPa into BPF preforms. VARI was used to infuse epoxy resin through the BPF preforms to make BPF composites. The flexural properties, impact property, and thermal properties of the BPF composites were analyzed. CaCO3 with the loading of 30 wt% affects the performance of the composites. The flexural strength did not decrease and modulus of the treated BPF composites increased by 9.38%, while the impact strength decreased by 50.98%, compared to the control sample. Dynamic mechanical analysis revealed the maximum elastic moduli of the treated specimens increased by 1.19 times in the temperature range of −20 to 120 °C. The thermal decomposition temperature of the composites was influenced by the effect of the crystal field and size effect of CaCO3.

Fatigue and Fracture Properties of Laminated Bamboo Strips from Gigantochloa scortechinii Polyester Composites

The fatigue and fracture properties of bamboo fiber composites made of woven layers were investigated. This study utilized a specific type of bamboo species named Gigantochloa scortechinii (Buluh Semantan). In these experiments, unsaturated polyester (UP) and bamboo fiber (BF) strips were prepared through a hand lay-up technique using 3-mm thick aluminum mould. The composite bamboo strips had a thickness of 1.5 mm. The strips were woven together to make a single layer. The layer was then laminated into several thicknesses. The specimens were then characterized using fatigue and fracture tests. A fatigue limit of 30 MPa and fracture toughness of 5 to 8 MPa √m were obtained. These findings suggest that the bamboo strips, based on unsaturated polyester, provided relatively good fatigue and fracture properties and a good method of reinforcing fibers to combat fatigue and fracture failures.

Applications of Fiber Reinforced Polymer Composites

Fueled by the need to surpass the limitations of conventional materials, recent years have seen a large increase in engineering applications of advanced fiber reinforced polymer (FRP) composite materials in many major industries, such as aerospace and defense, automotive, construction, marine, and oil and gas. FRP composites are very attractive for these applications due to their highly favorable material properties, including high strength-to-weight and stiffness-to-weight ratios, and corrosion resistance. Studies conducted to date have demonstrated the numerous advantages offered by FRP composites in various engineering applications. However, there are still a number of technical and implementation issues that need to be resolved prior to broader uptake of the application of FRP composites by some engineering communities such as civil construction. This special issue is aimed at disseminating the most recent advances and developments in this exciting field. A total of 17 paperswere submitted to the special issue and after a rigorous peer-review process six of themwere accepted to appear in the issue as original research articles. These six papers deal with a range of topics on the structural behavior of composite members/structures and mechanical properties and development of composite materials. The studies on the former investigate the dynamic behavior of composite FRP bridge systems and flexural behavior of previously damaged steel beams repaired with FRP. The studies on the latter are concerned with the development of ecoefficient engineered cementitious composites, mechanical properties of carbon fiber composites obtained using different molding techniques, and properties of high-density and ultra-high molecular weight polyethylene and heat-treated bamboo fiber composites. We hope that some of the most recent advances on the development and applications of FRP composites that have been disseminated in this special issue will be of interest to readers and contribute toward the advancement of research in the field.

폴리프로필렌/대나무 섬유 복합체의 물성에 대한 상용화제의 영향

Polypropylene (PP)/bamboo fiber (BF) composites were fabricated by twin screw extruder in order to investigate effects of the compatibilizer on physical properties of PP/BF composites. The content of BF changed from 10 to 25 wt% and that of the compatibilizer was fixed at 3 wt%. Maleic anhydride grafted PP (PP-g-MAH) was used to increase the compatibility be- tween PP and BF as a compatibilizer. Chemical structures of the composites were confirmed by the existence of carbonyl group (C=O) stretching peak at 1,700 cm -1 in FT-IR spectrum. Considering the degradation and mechanical properties, the optimum extrusion conditions were selected to be 210 ℃ and 100 rpm, respectively. There was no distinct changes in melting temperature of the composites, but the crystallization temperature increased by 10-20 ℃ owing to the heterogeneous nuclei of BF. It was checked that the optimum BF content was in the range of 15-20 wt% from the results of tensile and flexural properties of the composites. The effect of the compatibilizer on mechanical properties was confirmed by SEM images of fractured surface and contact angles.

High-Density Polyethylene and Heat-Treated Bamboo Fiber Composites: Nonisothermal Crystallization Properties

The effect of heat-treated bamboo fibers (BFs) on nonisothermal crystallization of high-density polyethylene (HDPE) was investigated using differential scanning calorimetry under nitrogen. The Avrami-Jeziorny model was used to fit the measured crystallization data of the HDPE/BF composites and to obtain the model parameters for the crystallization process. The heat flow curves of neat HDPE and HDPE/heat-treated BF composites showed similar trends. Their crystallization mostly occurred within a temperature range between 379 K and 399 K, where HDPE turned from the liquid phase into the crystalline phase. Values of the Avrami exponent (n) were in the range of 2.8~3.38. Lamellae of neat HDPE and their composites grew in a three-dimensional manner, which increased with increased heat-treatment temperature and could be attributed to the improved ability of heterogeneous nucleation and crystallization completeness. The values of the modified kinetic rate constant (KJ) first increased and then decreased with increased cooling rate because the supercooling was improved by the increased number of nucleating sites. Heat-treated BF and/or a coupling agent could act as a nucleator for the crystallization of HDPE.

Preparation and Carbonization Behavior of Bamboo Fiber Modified by Copolymerized Phenolic Resin

Copolymerized phenolic resin modified bamboo fiber composites(PR-BF) were prepared by a two step process i.e.firstly the bamboo fiber was immersed in an ultrasound irradiated bath of proper water solution of copolymerized phenolic resin and then undergone a heat treatment.The PR-BF composite was characterized by FTIR and its thermal property was examined by means of TG and DTG.The results show that bamboo fiber had excellent absorbability of phenolic resin; the phenolic resin is grafted on to bamboo fiber by copolymerization reaction; the thermal stability of the PR-BF composite increased dramatically with the increasing PR solid content in the solution; and the carbon residue of PR- BF reached a climax of 37.75% for the carburization at 900℃.From the FTIR analysis results it follows that in company with the thermal decomposition of PR-BF,a novel substitution product of benzene might form due to the copolymerization of BF with PR,which results in better thermal stability for PR-BF rather than the merely BF,and better resistance to elevated temperature rather than of the merely phenolic resin.Besides,after carburization the formed fiber-like nano-powders were good dispersed in PR-BF composite.

Investigation of Physical and Mechanical Properties of Bamboo Fiber and PVC Foam Sheet Composites

The bamboo fiber and PVC foam sheet composites were developed via hot compression molding process. Different percentages (0%, 5%, 8%, 12% and 15%) of bamboo fibers were introduced into the PVC foam sheets. Various physical and mechanical properties of the composites have been investigated. Bulk density decreases with the increase of percentage of fibers introduction to the PVC sheets. Percentage of water absorption was found to increases with the soaking time for all the samples. Mechanical properties e.g., tensile strength, flexural stress, flexural strain and tangent modulus of the composites are observed to be increases while the tensile strain decreases with the subsequent fiber addition to the PVC sheets. At the same time, the Young's modulus found to be increased up to 10% of the bamboo fibers introduction and then decreases with the further enhance of the fiber content. The maximum Young's modulus (1250 MPa) was found for 8 % of bamboo fiber to the PVC composite sheets. Thermal analysis confirmed the better thermal stability of bamboo fiber PVC composites.

Improvement of Mechanical Properties in Bamboo Maleic Anhydride Grafted Polypropylene/Polypropylene Composite Enhanced with Resin Impregnation Method

Previously bamboo fiber reinforced PP composites was manufactures using Polyvinyl Alcohol (PVA) and Phenolic resin for Resin impregnated bamboo fiber with polypropylene (PP). Using 40% weight fraction of bamboo fiber in PP matrix, PVA impregnated composites with mean flexural and tensile strength 10% higher than untreated were produced. The PVA treatment improved the tensile and flexural strength of bamboo/PP composites and increased water absorption ratio. Next, matrix modified with Maleic Anhydride grafted Polypropylene (MAPP). For matrix PP mixed with 10% of MAPP. In this study, resin impregnation method dose not make different for mechanical properties of composites. Untreated and PVA, Phnolic resin impregnated mechanical properties was almost same. However; it can decreased water absorption PVA resin absorption bamboo fiber composites.

Process-controlled optimization of the tensile strength of bamboo fiber composites for structural applications

A straightforward mechanical processing protocol for raw bamboo, which leads to a fibrous material with physical features that are mainly defined by the bamboo species, has been developed. This material was used as a natural fiber source for the production of a high-tensile fiber reinforced composite. Thereby, controlling the parameters of the underlying hot press fabrication process turned out to be crucial for a systematic tuning of the tensile capacities of the resulting composite materials. Hence, the relationship between tensile strength, pressure, temperature and press/hold time is being analyzed. It has been observed that the composites reach a maximum tensile strength (∼180MPa) at a certain pressure/temperature combination and any deviation from this range has a negative effect on the mechanical properties. The impact of the press/hold time, on the other hand, has been found to be rather small.

High performance of bamboo‐based fiber composites from long bamboo fiber bundles and phenolic resins

ABSTRACTLignocellulosic materials can be used for the development of bio‐based composites. This study explores the potential of long bamboo fiber bundles extracted directly from bamboo stems using the novel mechanical method and bamboo‐based fiber composites (BFC) fabricated using long bamboo fiber bundles and phenolic resins via cold pressing and thermal cure process. The microstructure, mechanical properties, and durability of BFC were evaluated, results being compared with raw bamboo and other commercialized bamboo fiber composites. The mechanical properties of BFC reinforced with 87% (w/w) long bamboo fiber bundles increased more than 50% than those of raw bamboo and were significantly higher than those of other bamboo‐based composites. Lower water absorption and thickness swelling were obtained in the case where bamboo fiber bundles with the small fineness. Higher tensile strength was obtained in the case where bamboo fiber bundles with large sizes of bamboo fiber bundles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40371.

Water Absorption Properties of Heat-Treated Bamboo Fiber and High Density Polyethylene Composites

To modify water absorption properties of bamboo fiber (BF) and high density polyethylene (HDPE) composites, heat treatment of BFs was performed prior to compounding them with HDPE to form the composites. The moisture sorption property of the composites was measured and their diffusion coefficients (Dm) were evaluated using a one-dimensional diffusion model. Moisture diffusion coefficient values of all composites were in the range of 0.115x10-8 to 1.267x10-8 cm2/s. The values of Dm decreased with increasing BF heat-treatment temperature, and increased with increasing BF loading level. The Dm value of 40 wt% bamboo fiber/HDPE composites with BFs treated with 100 oC was the greatest (i.e., 1.267x10-8cm2/s). Morphology analysis showed increased fiber-matrix interfacial bonding damage due to fiber swelling and shrinking from water uptaking and drying. The mechanism of water absorption of the composite, indicated a general Fickian diffusion process.

Improvement in the adhesion of bamboo fiber reinforced polylactide composites

Polylactide composites containing bamboo fiber treated with various coupling agents were prepared using melt compounding. 3aminopropyltriethoxysilane, vinyltrimethoxysilane, maleic anhydride, and acrylic acid were used as the coupling agents to improve the mechanical properties of polylactide and bamboo fiber composites. In addition, to investigate the effect of fiber diameter on mechanical properties, either split bamboo fiber or fibrillar bamboo fiber was used as reinforcement. The composites containing split bamboo fiber treated with 3aminopropyltriethoxysilane and acrylic acid exhibited the highest tensile strength of all composites prepared. In addition, the composites containing fibrillar bamboo fiber showed a marked improvement in tensile strength. To investigate the biodegradability of the composites, an enzymatic degradation test was performed using Proteinase K, a commonly used enzyme for polylactide degradation. All the polylactide composites containing bamboo fiber, regardless of which coupling agent was applied, showed a similar trend in enzymatic degradation to that of neat polylactide.

Effect of physicochemical structure of natural fiber on transverse thermal conductivity of unidirectional abaca/bamboo fiber composites

To study the effect of the microstructure of natural fiber on the transverse thermal conductivity of unidirectional composite, abaca and bamboo fibers were unidirectionally aligned to fabricate epoxy composites by a resin transfer molding (RTM) technique. The transverse thermal conductivity of these two types of composites was measured in a steady-state platform. X-ray diffractometer and scanning electron microscopy were applied to analyze the microstructure and morphology of both fibers and composites. The results indicated that the transverse thermal conductivity showed two types of tendencies with fiber content increasing: increasing for bamboo fiber composites, and decreasing for abaca fiber composites. The microstructure and theoretical analysis suggest that the lumen structure plays a great role rather than crystal structures and chemical compounds on the transverse thermal conductivity of unidirectional composites, which is useful for further development and design of natural fiber reinforced composites with better thermal insulation property for people’s daily life.

Effect of Filler Content and Alkalization on Mechanical and Erosion Wear Behavior of CBPD Filled Bamboo Fiber Composites

In this study the mechanical and erosion wear behavior of bamboo fiber reinforce epoxy composites filled with Cement By-Pass Dust (CBPD) were studied. The effect of CBPD content and alkalization on the various properties of these composites was also investigated. Taguchi’s orthogonal arrays are used for analysis of experiential results. It identifies significant control factors influencing the erosion wear and also outlines significant interaction effects. Analysis of variance (ANOVA) test has also been performed on the measured data to find the most significant factors affecting erosion rate. Finally, eroded surfaces of both untreated and alkali treated bamboo fiber reinforced composites were characterized using SEM.

Influence of chemical treatments on the mechanical and water absorption properties of bamboo fiber composites

Chemical surface modification of woven bamboo mat with maleic anhydride, permanganate, benzoyl chloride, benzyl chloride, and pre-impregnation were carried out. These modified fibers were used as reinforcements in epoxy and polyester matrices. The effects of fiber modification on the tensile, flexural, impact, and water absorption properties of the composites were investigated. Flexural properties of maleic anhydride treated bamboo polyester composites improved by nearly 50%. The tensile strength and modulus of permanganate-treated bamboo polyester composite increased by 58% and 118%. The tensile strength and modulus of benzoylated bamboo fiber polyester composite improved by 71% and 118%, respectively. After benzoylation of the bamboo fiber, the water absorption is 16% for the bamboo-epoxy composite compared to 41% by untreated bamboo-epoxy composite. The water absorption by benzylated bamboo reinforced polyester composite was 16.8% compared to 51% by untreated bamboo-polyester composite. Pre-impregnation improved the mechanical and water resistant properties of both epoxy and polyester-based composites. SEM investigations of the tensile fracture surfaces show that modifications improved the fiber—matrix interaction.

The Processing and Characterization of Polyester/Natural Fiber Composites

The mechanical, thermal, and morphological properties of polycaprolactone (PCL) and bamboo fiber (BF) composites were evaluated. Composites containing maleic anhydride-grafted PCL (PCL-g-MA/BF) exhibited noticeably improved mechanical properties due to better compatibility between the two components in comparison to PCL/BF. The dispersion of BF in the PCL-g-MA matrix was clearly more homogeneous due to the creation of branched and cross-linked macromolecules via reactions between anhydride carboxyl groups in PCL-g-MA and hydroxyl groups in BF. The tensile strength and elongation of the PCL-g-MA/BF composites at break was considerably greater than that of PCL/BF composites. In a soil environment, PCL/BF biodegraded slightly faster than PCL-g-MA/BF. Finally, the PCL-g-MA/BF composites not only provided a plateau tensile strength at break up to 40 wt% BF but also provided more easily processing properties.

Polyester biocomposites from recycled natural fibers: Characterization and biodegradability

AbstractThe structure, biodegradability, and morphological properties of composite materials composed of poly(butylene succinate adipate) (PBSA) and bamboo fiber (BF) were evaluated. Composites containing acrylic acid‐grafted PBSA (PBSA‐g‐AA/BF) exhibited noticeably enhanced compatibility between the two components. The dispersion of BF in the PBSA‐g‐AA matrix was highly homogeneous as a result of ester formation and the consequent creation of branched and crosslinked macromolecules between the carboxyl groups of PBSA‐g‐AA and hydroxyl groups in BF. In addition, the PBSA‐g‐AA/BF composite was more easily processed due to a lower melt viscosity. Each composite was subjected to biodegradation tests in an Acinetobacter baumannii compost. Morphological observations indicated severe disruption of film structure after 10–20 days of incubation, and both the PBSA and the PBSA‐g‐AA/BF composite films were eventually completely degraded. The PBSA‐g‐AA/BF films were more biodegradable than those made of PBSA and exhibited a lower molecular weight and intrinsic viscosity, implying a strong connection between these characteristics and biodegradability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Studies on the Water Absorption of Bamboo-Epoxy Composites: The Effect of Silane Treatment

The effect of silane treatments on the water absorption properties of bamboo matting reinforced epoxy composites were investigated. Treatments using γ-Aminopropyltriethoxy silane, 3-trimethoxysilylpropyl methacrylate, Vinyltris(2-methoxyethoxy)silane, Bis[3-(triethoxysilyl)propyl] tetrasulfide, 3-aminopropyltrimethoxy silane and n-Octyltrimethoxy silane were carried out to study the water absorption property of the bamboo composites. Water absorption in the composites was studied by long-term immersion and 2 h boiling in distilled water. The process of absorption of water was found to follow the kinetics and mechanism described by Fick's theory. Only aminosilanes have shown the positive effects, but to a limited degree. It has been found that among the various silanes used only aminopropyltriethoxy silane treatment is suitable for bamboo-epoxy composite. Aminopropyltriethoxy silane-treated bamboo fiber composite has decreased the water uptake from 41.42% to 36.87%.