Polyvinyl Chloride Reinforced with Areca Sheath Fiber Composites—An Experimental Study

ABSTRACT

This research work deals with fibrous composites obtained by using treated and untreated areca sheath (AS) fibers reinforced in polyvinyl chloride (PVC) by injection molding process. Surface treatments of fibers have been carried out to have a better compatibility with PVC matrix. The tensile and flexural strength have been found to increase at the early stage with the increase in treated areca fiber content till optimum (18 wt% of fiber) fiber loading thereafter declines. At optimum fiber loading, the tensile strength, flexural strength and young’s modulus values are 42.38 MPa, 18.22 MPa and 2.38 GPa, respectively, which give maximum values in comparison to other fiber loadings. Thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), biodegradability tests and scanning electron microscopy (SEM) have been used for analysis. The TGA inferred that the thermal stability of the composites increased as compared to neat PVC matrix. Further, the composites exhibit excellent biodegradability property and their biodegradability increases with the increase of areca fiber content. From the properties obtained at optimum fiber loading (18 wt% of fiber), the composite can be suitable for automotive dashboard and door panel applications.     

Effect of grafting generations of poly(amidoamine) dendrimer from the sisal fiber surface on the mechanical properties of composites

In order to improve the mechanical properties of sisal fiber-reinforced polypropylene composites, the sisal fibers were grafted with poly(amidoamine) dendrimer and the effects of grafting generations on the mechanical properties of composites were studied. The results reveal that the tensile, flexural, and impact strength of the composites are improved considerably with the poly(amidoamine) dendrimer grafting treatment. For the 2.0 generation treatment with the poly(amidoamine) dendrimer, the tensile, flexural, and impact strength of the composites at 30 wt% fiber loading increase by 29%, 13%, and 54%, respectively. However, the thermal and mechanical properties of the sisal fibers decrease after prolonged grafting treatment.     

Use of Residual Yeast Cell Wall for New Biobased Materials Production: Effect of Plasticization on Film Properties

The use of renewable resources to develop food contact materials, such as proteins or polysaccharides, and the use of industrial residues for alternative applications are trending topics for researchers and the industry. Yeast cell wall (YCW) is a very rich waste from the yeast extract industry. Due to this, the aim of this work is to develop new biodegradable films based on residual YCW and the study of the effect of plasticization on films properties. Residual YCW was used as base matrix and different concentrations of glycerol (0, 15, 25 and 35 wt%) were tested to obtain casted films. Homogeneous and yellow-brownish films, which allow seeing through them, were obtained from the YCW. Total soluble matter demonstrated that glycerol enhanced solubility of films but glycerol was retained in the polymer matrix. TGA studies indicated that YCW films exhibited substantial degradation at temperatures above 180 °C. FTIR spectra of the casted films were representative of yeast cell wall material and SEM photographs showed that cell wall maintained their shape after film formation. As expected, Young’s modulus and tensile strength values were decreased with the increasing amount of glycerol. However, elongation at break was not increased further with higher concentration of plasticizer and the addition of 15 wt% of glycerol seemed to be enough to improve mechanical properties. The linear increment of water vapour permeability with glycerol concentration was produced by the increase in water solubility in the film. Therefore, based on solubility in water, mechanical, and barrier properties, it is possible to propose yeast cells residues as film-forming material for biodegradable film developments.     

Mechanical,morphological, and thermogravimetric analysis of alkali-treated Cordia-Dichotoma natural fiber composites

ABSTRACT

Usage of composites with natural fiber reinforcement is drastically increasing in recent times because of their low density, biodegradable nature, and low cost. However, natural fibers have certain core problems such as poor adhesion between the fiber and matrix and a relatively high degree of moisture absorption. Alkaline treatment of natural fibers is aimed at improving the adhesive strength so that effective stress transferability takes place in the composite. In the present work, Cordia-Dichotoma fibers were treated with sodium hydroxide (NaOH) and composites were prepared with different weight ratios of these fibers reinforced with epoxy. The prepared composites were tested for their tensile and flexural strengths (mechanical properties). Besides, for a comprehensive material characterization, IR spectroscopy (FT-IR), scanning electron microscope, and thermogravimetric analysis were carried out. This work investigates the influence of aforementioned NaOH treatment on thermal, mechanical, and morphological properties of the composite material.     

Effect of alkali treatment on mechanical properties of woven jute composites

The effect of alkali treatment on the jute fabrics and its influence on jute composites properties has been studied. The plain woven jute fabrics were manufactured using handloom. The alkali treatment was optimized using Box and Benkhen experimental design using time, temperature and concentration as independent variables and water absorbency, weight loss percentage as dependent variables. The fabric treated with optimized condition of 5% NaOH for 4 h at 30 °C was made into a composite of [0°]₄ lay-up sequence by means of compression moulding technique using vinyl ester resin. The composites were characterized for various mechanical properties such as tensile, flexural and impact strength. It is observed from the results that the alkali-treated samples show increased mechanical properties of the composites which may be due to the better adhesion between the fabric and the resin because of the removal of lignin and hemicellulose.     

Effect of Curing Temperature on Mechanical Properties of Natural Fiber Reinforced Polymer Composites

Nowadays, growing environmental concerns have led many researchers to work in the area of natural fiber reinforced polymer composites. In this work, jute fiber has been used as reinforcement and epoxy as matrix material to develop partially biodegradable green composite with the help of hand layup followed by compression molding technique. The effect of curing temperature ranging from 80°C to 130°C on different samples was investigated for various mechanical properties. Results obtained from the various tests indicate that with increase in curing temperature, impact strength decreases, but tensile and flexural strength increases and decreases thereafter attaining the maximum value at 100°C between aforementioned temperature range. The trend obtained for mechanical properties is further justified through the study of morphology with scanning electron microscopy, and optimum curing temperature has been suggested.     

A new assessment on mechanical properties of jute fiber mat with egg shell powder/nanoclay-reinforced polyester matrix composites

ABSTRACT

Natural fiber polymer matrix composites occupy the major percentage in applications due to its ecofriendly and low-cost nature. This study investigates the mechanical properties of a polyester matrix nanocomposite reinforced by the NaOH-treated jute fabric mat (NJM) and untreated jute fabric mat (UJM). In addition, the effects of egg shell powder (ESP) and nanoclay (NC) to the above has also been studied. The matrices were prepared with different combinations of presence and absence of the ESP, NC, and both as well as different weight percentage using compression molding process. The mechanical and morphological properties of the composites were determined. The tensile strength, flexural strength, and impact strength of NJM with NC 1.5%wt and ESP 1.5%wt were found to be 29.28 MPa, 39.51 MPa and impact strength 3.03 J, respectively. This composition is superior to the other compositions. Morphological analysis of tensile fractured surface showed interfacial adhesion between UJM and NJM composites. NJM composites contained smaller amount of pullouts and the splits compared with the UJM composites, which hold up the better performance.     

Natural Fibers from Plantain Pseudostem (Musa Paradisiaca) for Use in Fiber-Reinforced Composites

Agricultural crops from plantain produce a significant amount of wastes and they are currently considered worthless. Accordingly, in this study, non-wood fibers from pseudostem of plantain plants were extracted through mechanical processing to be used as reinforcing material in polyester composites. Bio-based composites were obtained using a 4% wt. of lignocellulosic reinforcement and were prepared after the fibers underwent alkaline and acetylation treatments in order to enhance the compatibility of organic loads with the polyester matrix. The higher cellulose content of plantain fibers indicates that they can be used to reinforce composites with a polymeric matrix. The plantain fibers have bast fiber bundle of around 120 µm; single fibers of around 5 µm; and mesofibers with a diameter between 0.5 and 1 µm. The results showed that plantain fibers can be used as a filler material to obtain an alternative polymer composite. The flexural strength of composites (polyester with acetylated plantain fibers) was improved 28% when the properties are compared to control composite.     

玻璃纤维/光敏树脂复合材料的3D打印及其力学性能

为解决光固化3D打印树脂材料强度低的问题,将玻璃纤维与光敏树脂复合,采用光固化3D打印技术制备玻璃纤维增强复合材料,分析了玻璃纤维经硅烷偶联剂改性处理以及玻璃纤维的铺层方式对复合材料力学性能的影响。结果表明:玻璃纤维可提升复合材料的拉伸强度和弯曲强度,相比于未处理的玻璃纤维,经硅烷偶联剂处理的玻璃纤维对复合材料力学性能的提升更为显著,复合材料的拉伸强度提高了50%,弯曲强度提高了143%;相较于连续长纤维的铺层方式,采用模拟三维正交的铺层方式对于复合材料力学性能影响更为显著,拉伸强度提升了110%,而弯曲强度增加了147%。     

A study of the mechanical properties of pre-oxidized fiber felt/epoxy resin composite material

In this article, the pre-oxidized fiber felt composite material was firstly prepared by a mold press process, and the pre-oxidized fiber and resin were used as the reinforcing material and substrate of composite material, respectively. The pretreatment method of the pre-oxidized fiber felt and the impact of the amount of curing agent and the curing pressure on the mechanical properties of the composite material were studied, and the tensile and flexural properties were assessed to optimize the preparation process of composite material. Results show that when the curing agent accounts for 60% of the epoxy resin and the curing pressure is 3 MPa, the best tensile and flexural properties of the prepared composite material are achieved. The mechanical properties for the pretreated composite sheet prepared from pre-oxidized fiber were superior to those for the untreated sheet.     

Effect of alkali treatment on mechanical properties of the green composites reinforced with milkweed fibers

Polymeric composites disadvantages in terms of high price and non-recoverability make them unsuitable for some applications. Otherwise, natural fibers would be degraded easily and their prices are much lower as compared with most of the commonly used synthetic fibers, especially in composite manufacturing. Hollow Milkweed fiber with non-crimped nature is a known natural fiber which could have high potential to be used as composites reinforcements due to its low-density property. Increasing demand for natural fiber-reinforced composites as well as unique characteristics of Milkweed fibers reveal the need to study the mechanical properties of such fiber-reinforced composites. In this study, milkweed fibers were initially fed to laboratory carding machine in order to be formed as a nonwoven layer which was then applied to a low-velocity needle-punching operation. Surface modifications were carried out on the needle-punched nonwovens using 5% NaOH at 50–60 °C and three different treating time levels (30, 60 and 90 min). The produced nonwovens were then treated in a mixture of boiling water and detergent for 1 h. For making composite parts, the modified nonwovens were impregnated in Ploy vinyl acetate (PVAc) resin using the hand-layup method. The alkali treatment effects regarding the process time period on mechanical properties of the natural-reinforced composites were investigated. The findings suggested significant affectability of the composites mechanical properties by varying the time of alkali treatment, NaOH concentration as well as the type of surface modification process which are all mainly resulted in improving the interaction between fibers and matrix phase.     

Exploring the potential of milkweed stalk in wood plastic manufacture

The physical and mechanical properties of milkweed composites based on different loads of milkweed flour and maleic anhydride grafted polypropylene (MAPP) using polypropylene as matrix are investigated in this study. There levels of milkweed fibers (30, 40, and 50 wt.%), one level of mixed milkweed flour (20:20 wt.% fiber:bark), and two levels of MAPP (4 and 6 wt.%) were used to prepare natural fiber-reinforced composites. Physical and mechanical properties including flexural, tension, impact, and thickness swelling were evaluated according to ASTM standards. The result demonstrated that addition of milkweed flour fluctuates mechanical properties of reinforced composite. However, the optimum load of milkweed flour was different in each test. Generally, 40 wt.% mixed flour composite in comparison with 40 wt.% milkweed composite showed lower mechanical results and higher thickness swelling. MAPP as a coupling agent improved physical and mechanical properties of milkweed-filled composites in most properties. The results of this study depicted positive effects of lignocellulose fibers and coupling gent and also negative effect of bark flour as a function of lower cellulose and higher extractive contents on physical and mechanical properties of milkweed-reinforced composites.     

Effect of Chemical Treatment on Thermal,Mechanical and Degradation Behavior of Banana Fiber Reinforced Polymer Composites

ABSTRACT

The current research endeavor, explores the thermal, mechanical, and degradation behavior of alkaline treated banana fibers reinforced polypropylene composites. Composites incorporating BF (20% w: w) treated with NaOH (5% w: v) aqueous solution were developed using extrusion-injection molding processes. After chemical treatment, the tensile, flexural and impact strength of the composite increases by 3.8%, 5.17%, and 11.50%, respectively. Scanning electron microscope (SEM) observations of tested specimens confirm the fiber pull out and fiber fracture as the main reasons for failure of developed composites under tensile and impact loading. The specimens were exposed to two different environments, water immersion and soil burial for 5 weeks for the degradation studies. The degradation behavior of composites was measured in terms of variation in weight and mechanical properties (tensile, flexural, and impact). The maximum degradation in mechanical properties was observed for the composites buried under soil. The composite lost 7.69%, 12.06%, and 3.27% of tensile, flexural, and impact strength, respectively.     

Mechanical,Thermal, and Interfacial Characterization of Randomly Oriented Short Sisal Fibers Reinforced Epoxy Composite Modified with Epoxidized Soybean Oil

Short sisal fibers were reinforced in epoxidized soybean oil (ESO) modified toughened epoxy blends to improve the mechanical and thermo mechanical properties. Tensile modulus and tensile strength of the composite with 15 wt% sisal fiber were found to be increased as compared with bio-based epoxy blend. From DTG analysis, rate of degradation peak is found to be shifted to higher temperature revealing enhanced thermal stability of composite over base matrix. Dynamic mechanical analysis predicted higher storage modulus and higher glass transition temperature of bio-based epoxy composite. Scanning electron micrographs showed strong fiber-matrix adhesion. Contact angle measurement reveals the hydrophilic character of bio-based epoxy composite     

Effect of Green Gram Husk Nanocellulose on Banana Fiber Composite

Nanocellulose is a significant bio entity in the present-day applications of nanocomposites. In this regard, the present work focuses on fabrication of green gram husk cellulose-based hybrid nanocomposites. In the process of nanocellulose extraction, residues obtained after each stage of treatment are characterized through physical and morphological tests. Later, nanocellulose is reinforced in unsaturated polyester with 1, 3, 5, and 7 wt. % to study the tensile properties. The peak tensile strength is found to be 39 MPa at 5wt% of cellulose nanocomposites. Noting the enhancement in tensile properties of nanocomposites, nanocellulose is reinforced in banana fiber composites and its influence on mechanical properties is studied. Nanocellulose/banana fiber hybrid composites showed enhanced tensile strength, flexural strength, and impact strength.     

Application and characterisation of industrial brewing by-products in biodegradable starch-based expanded composites

Concern headed under waste management promotes the development and application of biodegradable materials. Naturally occurring lignocellulosic fibres, such as malt bagasse (MB), are often low-cost industrial by-products with attractive properties. This work focused on extruding starch-based expanded composites, containing two different brewing residues, Pilsen malt bagasse (PMB) and Weiss malt bagasse (WMB). Their mechanical, thermal and structural properties were evaluated. The expansion index was higher in the WMB10 extruded composite (25.73 ± 4.75), also evident in the SEM-FEG images which show more quantity and uniformity of pores. WMB5 and WMB10 resulted in a 50% decrease in composite water solubility relative to the Control. The hardness (N) of the samples was reduced by using MB fibres of both types, producing a less stiff and brittle material, which contributes to a potential application as alternative biodegradable packaging for non-biodegradable materials based on expanded polystyrene.     

Composites from Bast Fibres-Prospects and Potential in the Changing Market Environment

Abstract

Composite materials reinforced with natural fibres, such as flax, hemp, kenaf and jute, are gaining increasing importance in automotive, aerospace, packaging and other industrial applications due to their lighter weight, competitive specific strength and stiffness, improved energy recovery, carbon dioxide sequestration, ease and flexibility of manufacturing and environmental friendliness besides the benefit of the renewable resources of bast fibres. The market scenario for composite applications is changing due to the introduction of newer biodegradable polymers, such as PLA synthesized from corn, development of composite making techniques and new stringent environmental laws requiring improved recyclability or biodegradability for industrial applications where stress bearing capacities and micro-mechanical failures dictate serviceability. Bast fibre reinforced composites, made from biodegradable polymers, will have to compete with conventional composites in terms of their mechanical behaviour. Biocomposites, in which natural fibres, such as kenaf, jute, flax, hemp, sisal, corn stalk, bagasse or even grass are embedded in a biodegradable matrix, made as bioplastics from soybean, corn and sugar, have openedup new possibilities for applications in automotive and building products. Obviously, new approaches to research and development will be required to improve their mechanical properties, such as tensile, bending and impact resistance to match their performance and commercial competitiveness against petroleum based products. The research community has to look at the various possibilities of combining natural fibres, such as sisal, flax, hemp and jute with polymer matrices from non-renewable and renewable resources to develop cost effective biocomposites. This paper will review the newer products and techniques that can improve the properties of bast fibre based composites as well as potential structural and non-structural applications which can increase their market share.     

Diammonium phosphate-modified ramie fiber reinforced polylactic acid composite and its performances on interfacial,thermal, and mechanical properties

In this study, the properties of molded ramie fibers reinforced with polylactic acid (PLA) biocomposites were investigated. Before preparation of composites, diammonium phosphate (DAP) was applied to the surface of ramie fibers with and without pretreatments to analyze the interfacial adhesion of ramie–PLA composite. Wettability and adhesion behavior of ramie fibers in the PLA resin were characterized by contact angle (CA) measurements. The surface chemical analysis was performed by Fourier transform infrared spectroscopy (FTIR). The thermal properties were recorded using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The wetting analysis results showed that the introduction of DAP treatment to ramie fibers significantly improved the wetting behavior of ramie in the PLA resin. Similarly, the results of TGA indicated that DAP treatment substantially decreased the degradation temperature of the composites. The result of FTIR was also consistent with the results of wettability, TGA, and DSC for the observed changes of peaks in the transmission spectrum.     

碱处理对涤纶/光敏树脂复合材料力学性能的影响

针对光敏树脂经3D打印成型后试样力学性能较差问题,采用涤纶长丝增强光敏树脂的方法,使用光固化3D打印设备将涤纶长丝和光敏树脂复合成型制备涤纶增强复合材料。为获得较好的增强效果,对涤纶进行碱处理,研究了碱处理各条件下涤纶的减量率与纤维形貌和力学性能的关系,以及其对复合材料力学性能的影响。结果表明:随着减量率的增加,涤纶的形貌及力学性能改变越明显;当涤纶减量率为16.2%时,纤维表面出现连续纵向沟壑,力学强度下降6%,纤维的增强效果最好;经过改性处理的涤纶增强复合材料的拉伸强度和弯曲强度分别达到78 MPa和471 MPa,相比于未处理的纤维增强复合材料分别提升了66%和336%。     

Effect of Treatments on the Physical and Morphological Properties of SPF/Phenolic Composites

This study aims at evaluating the physical properties and effects of fiber treatments of natural fiber reinforced polymer composite’s friction applications. Sugar palm fibers (SPFs) were used as fillers (≤ 150 µm) with phenolic resin to fabricate the composites by the hot press technique. The loading of SPFs varied from 0 to 40 vol.% with an interval of 10 vol.% in phenolic composites. The fibers were treated with sea water for 30 days, and with 0.5 M of alkaline solution for 4 hrs. Rockwell hardness, density, voids content, water/oil absorption, and moisture content were studied. Scanning electron microscopy (SEM) was used to investigate the morphology and interfacial bonding of the fiber-matrix in composites. With an increase in the SPF loading in the composites, the results indicated a decline in Rockwell hardness, an increase in water/oil absorption, and density. It was also observed that higher the density of the composites, lower was the voids content. In terms of physical properties, sea water treatment showed better improvement than alkaline treatment. The outcome of this research indicated that SPFs can be effectively used in reinforcing polymer composites, such as friction composites.