Surface Of Bamboo Fibers Research Articles

Halloysite nanotubes immobilized by chitosan/tannic acid complex as a green flame retardant for bamboo fiber/poly(lactic acid) composites

AbstractIn order to develop an environmentally benign flame retardant for bamboo/PLA composites (BPC), chitosan (CS) and tannic acid (TA) were used as cationic and anionic polyelectrolyte respectively to stabilize halloysite nanotubes (HNT) on the surface of bamboo fiber (BF) and poly(lactic acid) (PLA). Mechanical performance tests showed that the flexural properties of BPC were moderately enhanced with the addition of HNT, while the incorporation of CS/TA complex (FR) exhibited a slight increase. The results of thermogravimetric analysis demonstrated that CS/TA complex and HNT improved the thermal stability of the BPC synergistically, which increased the char residue. Limiting oxygen index and cone calorimetry tests were used to study the flammability of BPC and the results showed that the addition of CS/TA complex and HNT had a synergistic effect on the flame retardant performance of BPC materials. The macroscopic and microscopic morphological studies confirmed the formation of HNT layer in the matrix of BPC/5FR@5HNT samples, which facilitated more stabile char residue with the best flame retardant performance.

Superhydrophobic and Superoleophilic Fiber from Waste Bamboo Processing Residues for Oil/water Selective Separation

Biomass materials have attracted increasing attention as oil absorbents for oil/water separation duo to their renewability, biocompatibility and biodegradability. However, many separation materials preparations are either rather time consuming or have suffered from the need of harsh conditions. In the present study, bamboo fiber was successfully modified to acquire simultaneously super-hydrophobic and super-oleophilic properties by just two steps: delignification and chemical vapor deposition (CVD). The morphology and properties of MTMS-bamboo fiber were characterized by SEM, FT-IR, XPS and the oil/water contact angles. Moreover, the durability, recyclability and the practical application of selective separation were studied. The analysis results disclosed that the special surface wetting properties of MTMS-bamboo fiber resulted from the silanization of the bamboo fiber surface, notably, from its water contact angle being 153° and oil contact angle 0°. The fiber so prepared exhibited excellent durability in several kinds of chemical solutions. The absorbed oil can be recovered by simple mechanical squeezing and the bamboo fiber maintained a high oil absorption capacity after multiple squeezing-absorption cycles. The modified fiber acted as an absorbent for hot water oil/water separation and demonstrated also a high oil separation capacity. The continuous separation efficiency of the MTMS-bamboo fiber was investigated.

Enhanced electromagnetic interference shielding capability in bamboo fiber@polyaniline composites through microwave reflection cavity design

Natural, electrical insulating bamboo fiber (BBF) was selected as cost-effective frameworks to fabricate electromagnetic interference (EMI) shielding composites. The compacted polyaniline (PANI) layer was formed on the surface of BBF through an in-situ polymerization process. The formation of the continuous PANI layer was attributed to the interaction between the aniline monomers and BBF surface. Three-dimensional electromagnetic reflection cavities were facilely constructed by this unique architecture. The electromagnetic properties are extensively investigated with respect to electrical conductivity, complex permittivity and permeability, loss tangent, and Cole-Cole analysis. By manipulating the mass ratio of BBF with different size, BBF@PANI possessed a high electrical conductivity of 8.99 ± 0.43 S/cm. Combined with the results of skin depth, attenuation constant, also comparisons of experimental results and theoretical predictions, it was found that besides the conductivity and dielectric loss, the compacted microwave reflection cavity could also boost the EMI shielding effectiveness (SE). By introducing effective multiple reflections, the absorption ability was enhanced. The EMI SE could even reach 45.0 dB with only 0.4 mm thickness. The attenuation of microwave was predominantly governed by an absorption mechanism. Furthermore, the SE per unit thickness could be as high as 1125.0 dB/cm, which is much higher than those other types of PANI-based materials. With outstanding EMI shielding performance, these BBF@PANI heterostructures offer promising prospects of lightweight, cost-effective and excellent performance EMI shields. We firmly believe that this research will be an effective platform for the development of green electromagnetic attenuators in the future.

Mechanical and thermal properties of bamboo fiber reinforced polypropylene/polylactic acid composites for 3D printing

In this article, a kind of degradable composite was prepared from bamboo fiber (BF), poly lactic acid (PLA), and polypropylene (PP). The mechanical and thermal properties were characterized by the universal testing machine, thermogravimetric analysis, differential scanning calorimetry. In order to improve the compability between BF and polymer matrix several modification on the surface of BF were explored and compared. Moreover, a compatibilizer (maleated PP) was applied to further increase compatibility between the fiber and matrix. It is found that the thermal stability of BF/PP/PLA composites decreased with the increase of maleated polypropylene (MAPP) content. When 5% MAPP was used the tensile strength, flexural strength, and impact strength of composites reached 33.73, 47.18 MPa, and 3.15 KJ/m2, with an increase by 13, 11.7, and 23.5%, respectively, compared with the composites without MAPP. The improvement of mechanical properties is attributed to the fact that irregular grooves and cracks induced by the modification of BF facilitate the infiltration of polymer into fiber due to the strong capillary effect. Furthermore, BF/PP/PLA composites are potential to be used in 3D printing. POLYM. ENG. SCI., 59:E247–E260, 2019. © 2018 Society of Plastics Engineers

Mesoporous aluminosilicate improves mildew resistance of bamboo scrimber with Cu[sbnd]B[sbnd]P anti-mildew agents

The mesoporous aluminosilicate synergy with CuBP anti-mildew agent was studied with the objective of improving the mildew resistance of bamboo scrimber. The SiAl inorganic film with enormous pore volume, was added to cover on the bamboo fiber's surface by a simple and sustainable dip-coating process. The results showed that the process decreased the leachability of the anti-mildew agents, which would improve efficiency of preservative agents and extend service life for the bamboo-based products. The average mold control effectiveness of three types of mold and stain fungi of the final product was greatly improved with 91.75% in optimized samples. In addition, the outdoor test indicated that the anti-mildew agents worked satisfactorily and no evidence of microbes infection and stain was found in bamboo scrimbers prepared by optimum processing parameters.

Preparation and characterization of polylactic acid-g-bamboo fiber based on in-situ solid phase polymerization

This study details effort to improve the interfacial compatibility of bamboo fiber/polylactic acid composites, by attaching the molecular chain of polylactic acid (PLA) to bamboo fibers (BF). The BF was pretreated using a 1 wt% sodium hydroxide solution and the lactic acid was then grafted onto BFs using in-situ solid phase polymerization. The prepared PLA grafted BF (PLA-g-BF) was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), the results confirmed that the grafting reaction occurred successful. The grafting ratio of the PLA-g-BF was 16.51% and the degree of substitution was 35.59%. The effect of reaction temperature and time on the degree of substitution of the PLA-g-BF was studied. The results showed that a reaction temperature of 80 °C and a reaction time of 7 h were the optimum conditions. The hydrophobicity, surface morphology, crystal structure, thermal properties and tensile properties of the PLA-g-BF were characterized. The results demonstrated that the surface and interior of BF were covered with PLA. The crystalline structure of the BF was somewhat damaged, which decreased its crystallinity and tensile strength. The grafting reaction improved the thermoplasticity and thermogravimetric performance of the PLA-g-BF. Moreover, the hydrophobicity of the PLA-g-BF was significantly increased.

Enhanced mechanical properties of bamboo fiber/HDPE composites by grafting poly(amido amine) onto fiber surface

The mechanical properties of bamboo fiber composites depend on the interfacial strength between fiber and high-density polyethylene (HDPE) matrix. Different poly (amido amine) (PAMAM) dendrimers were grafted onto bamboo fiber to improve the interfacial strength of the resulting composites. The surface morphology of the resulting materials was characterized by scanning electron microscopy and atomic force microscope. Surface characteristic the bamboo fiber surface were examined by X-ray photoelectron spectroscopy and Fourier transform infrared (FT-IR). The characterization results revealed that PAMAM were chemically grafted onto the surface of bamboo fiber.

Mussel-Inspired Polydopamine as a Green, Efficient, and Stable Platform to Functionalize Bamboo Fiber with Amino-Terminated Alkyl for High Performance Poly(butylene succinate) Composites.

A new and eco-friendly mussel-inspired surface modification pathway for bamboo fiber (BF) is presented in this study. The self-assembly polydopamine (PDA) coating can firmly adhere on BF surface, which also serves as a bridge to graft octadecylamine (ODA) for hydrophobic surface preparation. The as-formed PDA/ODA hybrid layer could supply abundant hydrophobic long-chain alkyls groups and generated a marked increase in BF surface roughness and a marked decrease in surface free energy. These changes provided advantages to improve fiber–matrix interfacial adhesion and wettability. Consequently, high performance was achieved by incorporating the hybrid modified BF into the polybutylene succinate (PBS) matrix. The resultant composite exhibited excellent mechanical properties, particularly tensile strength, which markedly increased by 77.2%. Meanwhile, considerable high water resistance with an absorption rate as low as 5.63% was also achieved. The gratifying macro-performance was primarily attributed to the excellent interfacial adhesion attained by hydrogen bonding and physical intertwining between the PDA/ODA coating on the BF and the PBS matrix, which was further determined by fracture morphology observations and dynamic mechanical analysis. Owing to the superior adhesive capacity of PDA, this mussel-inspired surface modification method may result in wide-ranging applications in polymer composites and be adapted to all natural fibers.

Enhanced mechanical and thermal properties of poly (lactic acid)/bamboo fiber composites via surface modification

Three different kinds of surface treatment procedures were used to modify the surface of bamboo fiber: alkali solution treatment (NaOH), alkali and silane coupling agent treatment (NaOH–KH550) and alkali and titanate coupling agent treatment (NaOH–NDZ201). Then the bamboo fiber reinforced poly (lactic acid) composites were prepared by Haake Mixer and characterized by FTIR spectroscopy, mechanics performance tests, differential scanning calorimetry analysis, thermogravimetric analysis, Vicat softening temperature, X-ray diffraction analysis and scanning electron microscopy. The results showed that incorporation of surface-treated bamboo fiber obviously improved the mechanical properties of poly (lactic acid). Especially, the tensile, flexural and impact strengths of poly (lactic acid) containing NaOH–NDZ201-treated bamboo fiber were higher than those of poly (lactic acid) containing NaOH and NaOH–KH550-treated bamboo fiber. Moreover, the NaOH–NDZ201-treated bamboo fiber also greatly enhanced the thermal stability of poly (lactic acid). The improvement of mechanical strengths and thermal stability of poly (lactic acid)/bamboo fiber composites might be due to the better interfacial adhesion between poly (lactic acid) and NaOH–NDZ201-treated bamboo fiber.

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.

Mechanical properties and prediction for nanocalcium carbonate-treated bamboo fiber/high-density polyethylene composites

Nanocalcium carbonate (CaCO3) was successfully adhered to the surface of bamboo fiber (BF) via both impregnation and blending modification. The BF-, BMBF (bamboo fiber treated by blending modification)- and IMBF (bamboo fiber treated by impregnation modification)-reinforced high-density polyethylene (HDPE) composites were all manufactured by means of extrusion molding. The flexural and impact properties of the composites (the addition of BF, BMBF and IMBF were all 30 wt%) were analyzed. CaCO3 with a loading of 15 wt% had an effect on the performance of the composites. The flexural strength (FS) of the BMBF and IMBF composites increased by 1.09 and 9.36%, respectively, while the differences of the impact strength were insignificant among these, compared to the BF/HDPE composites. The flexural properties of the IMBF/HDPE composites were investigated with different mass fractions of IMBF (5, 10, 15, 20, 30, 50, 60 and 70 wt%). The results showed that the FS of the IMBF/HDPE composites reached a maximum value (58.99 MPa) when the mass fraction of the IMBF was 30 wt% and increased by 50.95% compared to when the mass fraction was 5 wt%. These results were supported by ESEM and fractal dimension analysis in terms of proper distribution of nano-CaCO3 and interfacial adhesion between the IMBF and HDPE matrix. The results revealed that the fractal dimension D of IMBF/HDPE composite with a mass fraction of 30 wt% reached a maximum value (2.2036), which was similar to the FS results. There was a linear correlation between lg (FS) and fractal dimension D, indicating that the fractal dimension was practicable for the IMBF-reinforced HDPE composites. The fractal features could reflect the macro-mechanical properties, and the percentage error of the fitting function was within 10%.

Effect of alkali treatment on microstructure and mechanical properties of individual bamboo fibers

The aim of this study was to study the microstructure and mechanical properties of individual bamboo fibers after alkali treatment. The individual bamboo fibers were treated by sodium hydroxide (NaOH) solution with varying concentration (6, 8, 10, 15 and 25%) followed by rinsing and freeze-drying treatments. The alkali treated individual bamboo fibers were subsequently characterized by scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, confocal laser scanning microscopy and tensile strength tests. The results indicated that the alkali treatment resulted in more wrinkles and pores on the surface of bamboo fibers. Microfibril aggregates treated by 15 and 25% NaOH solution changed from a randomly interwoven structure to a granular structure. Cellulose I was transformed to cellulose II after 15 and 25% NaOH solution treatment. The alkali treatment reduced the diameter, lumen and cross sectional area of fiber, leading to the cracks in cell wall. The tensile strength and modulus of elasticity (MOE) of individual bamboo fibers decreased with alkali treatment. NaOH concentration almost did not affect the tensile strength but influenced the MOE significantly. The elongation at break of treated individual fiber increased significantly. When compared to untreated individual fibers, the elongation at break of the fiber was increased by 232 and 221% after 15 and 25% NaOH treatments, respectively. Besides, increasing alkali concentration caused the change of the fibers from brittleness to ductility, indicating that alkali treated bamboo fibers have a promising application in textile.

석류과피 색소의 키토산 처리한 대나무/면 혼방직물에 대한 염색성과 항균성

Concern for the environment, depletion of fossil fuels, and consumer demand for eco-friendly and well-being are driving force to develop green products. There has been growing demand to develop finishes for textile materials imparting protection against microbes. Bamboo is one of abundant renewable biomass materials. Bamboo fiber which is one of regenerated cellulose fibers is already been used for textile products. Bamboo fiber has many useful properties such as antibacterial, high absorbency and hygroscopicity, and UV-resistant property [1,2]. It has cool and smooth feel, and excellent wicking so that is suitable for summer clothing, dishcloth, gauze bandage, medical drape, towel, etc. In most cases surface of bamboo fiber has negative charges and so, cationic polymers readily adsorbed onto the surface of bamboo fiber [3]. Bamboo fiber, which is otherwise not dyeable with acid dyes, coluld be renderd acid dyeable by acrylamide grafting onto bamboo fiber [2]. For better performance properties, it is usually blended with other fibers such as cotton, hemp, silk, Lyocell(Tencel), Modal, cotton chemical fiber and so on [4]. The cross-section of bamboo fiber is filled with various micro-gaps and micro-holes. With this unparalleled micro-structure, bamboo fiber can absorb and evaporate sweat very quickly [1]. Pomegranate (Punica granatum L.) belonging to the family Punicacea, is originally a native of Persia and nowadays it is generally cultivated at warm countries in the world. Corresponding Author: Younsook Shin E-mail: yshin@chonnam.ac.kr

Composite films of N,O‐carboxymethyl chitosan and bamboo fiber

ABSTRACTTo obtain an antibacterial chitosan derivative, composite films of N,O‐Carboxymethyl Chitosan (N,O‐CMCS) and bamboo fiber were prepared. A water‐soluble chitosan derivative‐N,O‐CMCS was synthesized from chitosan with chloroacetic acid in alkaline solution. Composite films with 1–5 wt % N,O‐CMCS content were prepared in NaOH/urea/thiourea solution. The DS of N,O‐CMCS reached 1.70 and the water solubility increased with the increasing of DS. The carboxymethyl group was introduced into chitosan, which led to the decrease of thermal stability and crystallinity. The structural characterization confirmed that N,O‐CMCS was adsorbed on the surface of bamboo fiber. The antibacterial performance of the composite films were enhanced with the increasing of N,O‐CMCS content. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39851.

Influence of fiber extraction and surface modification on mechanical properties of green composites with bamboo fiber

Environment-friendly fiber reinforced composites were fabricated using bamboo fibers and vinylester resin by the vacuum assisted resin transfer molding technique. Prior to green composites fabrication, bamboo fiber bundles were extracted by three methods, namely steam explosion, alkali extraction, and chemical extraction. Bamboo fiber bundles were characterized for their interfacial shear strength (IFSS) and tensile properties using the Weibull distribution. The effects of surface modification and water absorption were investigated for green composites with bamboo fibers that were surface-modified by sodium hydroxide (alkali) and silane coupling agent. The tensile properties of bamboo fiber bundle decreased in all conditions compared to raw bamboo fiber, but IFSS increased with chemical treatment due to the effective removal of hemicellulose and lignin from surface of bamboo fiber. The alkali/silane treated fiber composites show higher mechanical and durability properties against water absorption than other surface-modified fiber composites.

Preparation, characterization of carboxylated bamboo fibers and their adsorption for lead(II) ions in aqueous solution

The present study was conducted to develop a simple and versatile method to prepare carboxylated bamboo fibers which can be applied as potential bio-adsorbent for metal ions removal due to the high content of carboxyl groups. The chemical modification of bamboo fibers with citric acid (CA) was carried out by friendly semi-dry oven method. The resulting products with carboxyl group content between 1.99 and 4.13 mmol/g were accessible by changing ultrasonic pretreatment time, reaction temperature, reaction time and the amounts of catalyst and citric acid in order to minimize cross-linking reaction and thereby maximize carboxyl groups content. The characterization of the resulting products confirmed that carboxyl groups were successfully grafted onto surface of bamboo fibers. Moreover, the carboxylated bamboo fibers could be applied as bio-adsorbent for the removal of lead(II) ions from aqueous solution. Results showed that the adsorption capacity of Pd2+ could reach 127.1 mg/g for carboxylated bamboo fibers with 4.13 mmol/g carboxyl group content prepared under the ultrasonic pretreatment for 20 min at the CA/bamboo fibers weight ratio of 4.0 in the catalyst amount of 30 wt% at 120 °C for 90 min and the carboxylated bamboo fibers exhibited highly efficient regeneration with no significant loss of adsorption capacity of lead ion after five repeated adsorption/desorption cycles.

Influence of surface treatments on structural and mechanical properties of bamboo fiber-reinforced poly(lactic acid) biocomposites

Bamboo fiber-reinforced polylactic acid (PLA) composites were prepared using a film-stacking process. Bamboo fibers were treated using three different methods, i.e., direct silane coupling (DC), silane coupling after plasma (CAP) treatment, and silane coupling during UV irradiation (CDU), to improve the interfacial bonding strength between fibers and PLA. After surface treatment, the chemical group on the surface of bamboo fibers was analyzed through Fourier transform infrared spectroscopy. The intensity of bands around 880–900 cm−1 increased strongly. These results suggested that the grafting of silane onto fibers was enhanced substantially. X-ray diffraction analysis indicated that the amorphous region of the CDU- and CAP-treated fibers increased. The interfacial shear strength between the fibers and the matrix also increased by 44.2%, 64.2%, and 87.4% by DC, CDU, and CAP treatment, respectively. In addition, the tensile strength of bamboo–PLA composites with DC-, CDU-, and CAP-treated fibers increased 43.0%, 61.1%, and 71.2%, respectively. Moreover, the predicted tensile modulus of the composites with CAP-treated fibers showed good agreement with the experimental one.

Relationship between fiber chemical treatment and properties of recycled pp/bamboo fiber composites

This article reports the preparation of recycled polypropylene (RPP)/bamboo fiber (BF) composite via direct melt blends using a twin screw extruder. The effects of the chemical treatment of BF surface (alkaline and acetylation) on fiber structure and composite mechanical, thermal, rheological properties have been investigated. We showed that alkali treatment increases the contact surface of BF within composites, resulting in a more homogenous dispersion of fibers in the polymer matrix. Alkali treatment improves mechanical properties such as tensile strength as well as the Charpy impact strength. Reinforced composites obtained with acetylated BF show better mechanical properties due to grafting of acetyl groups onto the cellulose fiber surface and thus improve compatibility between BF and matrix. The rheological properties of RPP/BF composites depending on the BF content and treatment methods are also analyzed. Predominant factors that influence the properties of relevant materials are identified. Maleic anhydride grafted polypropylene is used as a compatibilizer to improve the adhesion between the cellulosic phase and the RPP matrix.

FLEXURAL PROPERTIES OF INJECTION-MOLDED BAMBOO/PBS COMPOSITES

In recent years, from an environmental perspective, there has been increasing interest in the change to a sustainable society. The use of natural-fiber-reinforced biodegradable composites has been proposed as one solution. Bamboo is an often used renewable bio-resource; it has an inherent advantage of rapid growth. Polybutylene succinate ( PBS ), used as matrix resin, has biodegradable characteristics. This paper describes flexural properties of bamboo/ PBS composites prepared by injection molding. The following results were obtained. The flexural modulus was improved with increasing bamboo powder contents when the cylinder temperature of the injection molder was 140°C. However, the flexural strength showed the opposite tendency to be decreased with increasing bamboo powder contents. An SEM photomicrograph of the fracture surface for bamboo/ PBS composites showed typical fracture behavior of pull-out fibers without fiber fracture. Furthermore, there was no adhesion of PBS resin on the bamboo fiber surface. Processing conditions affected mechanical properties of bamboo/ PBS composites, imparting higher flexural strength and flexural modulus at high cylinder temperatures such as 180°C and 200°C.

Effective Degree of Fibrillation of Micro-Fibrillated Bamboo Fiber Processed by Stone Mill for Improving Mechanical Properties of PLA Composite

Current paper proposes an effective technique to improve mechanical properties of bamboo fiber reinforced PLA (Poly Lactic Acid) by fibrillation on the surface of bamboo fibers (BFs). To improve the interfacial properties between bamboo fibers and matrix, the surface of alkali treated bamboo pulp was fibrillated by milling machine. The bamboo pulps were milled under 3 different conditions (Fibrillated Alkali Bamboo fiber : FAB). Degree of fibrillation (D.F.) was defined as water retention of the bamboo fiber. Four types of bamboo fiber were prepared in this study ; the D.F was 0 (pulp), 3.5, 4.3 and 4.8. The FAB/PLA composites were injection molded after fibrillated bamboo fibers were mixed into PLA. The effect of fibrillation on mechanical properties of BF/PLA composite was investigated.The viscosity of melted FAB/PLA was increased and the rate of crystallization decreased when the bamboo fiber was processed with large number of (D.F.). The bending strength and interfacial shear strength of FAB/PLA composites was significantly increased in comparison to that of the original bamboo pulp/PLA composite when the D.F. was selected to 3.5, compared to that of un-fibrillated AB/PLA composites. Long pull-out of the fiber with smooth surface was observed on the fracture surfaces of un-fibrillated AB/PLA composites. However, the bending strength of FAB/PLA composites was decreased when the D.F. was 4.3 and 4.8. The discussion in the paper showed that the decrease in strength of fibrillated bamboo fiber and change of fiber orientation should degrade the bending strength of FAB/PLA composite when the fiber was excessively fibrillated. This paper mentioned the optimum condition was there to enhance interfacial properties between bamboo fiber and PLA matrix.