Enhancement of PVC/ENR blend properties by poly(methyl acrylate) grafted oil palm empty fruit bunch fiber

Effect of oil palm empty fruit bunch (OPEFB) fiber and poly(methyl acrylate) grafted OPEFB on several mechanical properties of poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blends using HAKEE Rheomixer at the rotor speed of 50 rpm, mixing temperature 150°C, and mixing period of 20 min. The fiber loadings were varied from 0 to 30% and the effect of fiber content in the composites on their ultimate tensile strength (UTS), Young's modulus, elongation at break, flexural modulus, hardness, and impact strength were determined. An increasing trend was observed in the Young's modulus, flexural modulus, and hardness with the addition of grafted and ungrafted fiber to the PVC/ENR blends. However the impact strength, UTS, and elongation at break of the composites were found to decrease with the increase in fiber loading. An increase in elongation at break and UTS and decrease in the flexural and Young's modulus was observed with the addition of PMA‐g‐OPEFB fiber compared to ungrafted fiber. This observation indicates that grafting of PMA onto OPEFB impart some flexibility to the blend. The morphology of cryogenically fractured and tensile fracture surfaces of the composites, examined by a scanning electron microscope shows that the adhesion between the fiber and the matrix is improved upon grafting of the OPEFB fiber. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Tensile properties of short sisal fiber reinforced polystyrene composites

The tensile properties of polystyrene reinforced with short sisal fiber and benzoylated sisal fiber were studied. The influence of fiber length, fiber content, fiber orientation, and ben-zoylation of the fiber on the tensile properties of the composite were evaluated. The ben-zoylation of the fiber improves the adhesion of the fiber to the polystyrene matrix. the benzoylated fiber was analyzed by IR spectroscopy. Experimental results indicate a better compatibility between benzoylated fiber and polystyrene. the benzoylation of the sisal fiber was found to enhance the tensile properties of the resulting composite. The tensile properties of unidirectionally aligned composites show a gradual increase with fiber content and a leveling off beyond 20% fiber loading. The properties were found to be almost independent of fiber length although the ultimate tensile strength shows marginal improvement at 10 mm fiber length. The thermal properties of the composites were analyzed by differential scanning calorimetry. Scanning electron microscopy was used to investigate the fiber surface, fiber pullout, and fiber–matrix interface. Theoretical models have been used to fit the experimental mechanical data. © 1996 John Wiley & Sons, Inc.     

Tensile properties of a poly(vinyl chloride) composite filled with poly(methyl methacrylate) grafted to oil palm empty fruit bunches

The influence of oil palm empty fruit bunch (OPEFB) fiber and oil palm empty fruit bunches grafted with poly(methyl methacrylate) (OPEFB‐g‐PMMA) on the tensile properties of poly(vinyl chloride) (PVC) was investigated. The OPEFB‐g‐PMMA fiber was first prepared with the optimum conditions for the grafting reaction, which were determined in our previous study. To produce composites, the PVC resin, OPEFB‐g‐PMMA fiber or ungrafted OPEFB fiber, and other additives were first dry‐blended with a laboratory blender before being milled into sheets on a two‐roll mill. Test specimens were then hot‐pressed, and then the tensile properties were determined. A comparison with the composite filled with the ungrafted OPEFB fiber showed that the tensile strength and elongation at break increased, whereas Young's modulus decreased, with the incorporation of 20 phr OPEFB‐g‐PMMA fiber into the PVC matrix. The trend of the tensile properties obtained in this study was supported by functional group analysis, glass‐transition temperature measurements, and surface morphological analysis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Mechanical and morphological properties for sandwich composites of wood/PVC and glass fiber/PVC layers

This work manufactured sandwich composites from glass fiber/poly(vinyl chloride) (GF/PVC) and wood/PVC layers, and their mechanical and morphological properties of the composites in three GF orientation angles were assessed. The effects of K value (or viscosity index) of PVC and Dioctyl phthalate (DOP) loading were of our interests. The GF/PVC was used as core layer whereas wood/PVC was the cover layers. The experimental results indicated that PVC with low K value was recommended for the GF/PVC core layer for fabrication of GF/WPVC sandwich composites. The improvement of PVC diffusion at the interface between the GF and the PVC core layer was obtained when using PVC with K value of 58. This was because it could prevent de‐lamination between composite layers which would lead to higher mechanical properties of the sandwich composites, except for the tensile modulus. The sandwich composites with 0° GF orientation possessed relatively much higher mechanical properties as compared with those with 45° and 90° GF orientations, especially for the impact strength. Low mechanical properties of the sandwich composites with 45° and 90° GF orientation angles could be overcome by incorporation of DOP plasticizer into the GF/PVC core layer with the recommended DOP loadings of 5–10 parts per hundred by weight of PVC components. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Studies on mechanical properties of polyethylene–organic fiber composites. I. Nut shell flour

Composites were made from polyethylene and an organic fiber (pecan shell and peanut hull flour) using a compression-molding technique. Studies of variations in molding temperature (145–180°C), fiber concentration (0–40% by weight), and fiber mesh size (100, 200, and 325) were correlated to the mechanical properties of the composites (tensile strength, elongation, fracture energy, modulus, and impact strength). In untreated nut shell composites, tensile strength decreased steadily as the fiber concentration increased. This was due to poor bonding between the untreated fiber and polymer. Polyisocyanate was used as a coupling agent and its effect on mechanical properties of the composites was studied. Significant improvement in tensile strength was achieved with an isocyanate coupling agent, but it had no effect on modulus of the composites. Both untreated and isocyanate-treated composites had lower impact strength values; further composite matrix modifications would be necessary to maintain or improve impact strength.     

Mechanical,thermal, and morphological properties of maleic anhydride‐g‐polypropylene compatibilized and chemically modified banana‐fiber‐reinforced polypropylene composites

Composites were prepared with chemically modified banana fibers in polypropylene (PP). The effects of 40‐mm fiber loading and resin modification on the physical, mechanical, thermal, and morphological properties of the composites were evaluated with scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Infrared (IR) spectroscopy, and so on. Maleic anhydride grafted polypropylene (MA‐g‐PP) compatibilizer was used to improve the fiber‐matrix adhesion. SEM studies carried out on fractured specimens indicated poor dispersion in the unmodified fiber composites and improved adhesion and uniform dispersion in the treated composites. A fiber loading of 15 vol % in the treated composites was optimum, with maximum mechanical properties and thermal stability evident. The composite with 5% MA‐g‐PP concentration at a 15% fiber volume showed an 80% increase in impact strength, a 48% increase in flexural strength, a 125% increase in flexural modulus, a 33% increase in tensile strength, and an 82% increase in tensile modulus, whereas the heat deflection temperature increased by 18°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Comparative study of the effects of chlorinated polyethylene and acrylic impact modifier on the thermal degradation of poly(vinyl chloride) compounds and poly(vinyl chloride)/(oil palm empty fruit bunch) composites

The effects of chlorinated polyethylene (CPE) and acrylic impact modifier (AIM) on the thermal degradation of poly(vinyl chloride) (PVC) compounds and composites were investigated. The amounts of AIM and CPE used were fixed at 9 parts per hundred parts of resin (phr), while oil palm empty fruit bunch (OPEFB) fiber content was increased from 0 to 40 phr. To produce composites, the PVC formulations were dry‐blended by using a laboratory blender before being milled into sheets on a two‐roll mill at 165°C. The milled sheets were then hot‐pressed at 180°C. The thermal degradation of the specimens was evaluated by using thermogravimetry in a nitrogen environment. Thermal stability of the PVC/CPE compounds and PVC/CPE/OPEFB composites was improved by the addition of CPE. The CPE retarded the dehydrochlorination of PVC. However, the stabilization effect was reduced by the incorporation of OPEFB at levels of 30 and 40 phr. The presence of AIM accelerated the dehydrochlorination of PVC/AIM compounds and PVC/AIM/OPEFB composites. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers     

Effect of alkali treatment on properties of unidirectional isora fibre reinforced epoxy composites

Abstract

Unidirectional isora fibre reinforced epoxy composites were prepared by compression moulding. Isora is a natural bast fibre separated from Helicteres isora plant by retting process. The effect of alkali treatment on the properties of the fibre was studied by scanning electron microscopy (SEM), IR, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Mechanical properties such as tensile strength, Young's modulus, flexural strength, flexural modulus and impact strength of the composites containing untreated and alkali treated fibres have been studied as a function of fibre loading. The optimum fibre loading for tensile properties of the untreated fibre composite was found to be 49% by volume and for flexural properties the loading was optimised at ～45%. Impact strength of the composite increased with increase in fibre loading and remained constant at a fibre loading of 54·5%. Alkali treated fibre composite showed improved thermal and mechanical properties compared to untreated fibre composite. From dynamic mechanical analysis (DMA) studies it was observed that the alkali treated fibre composites have higher E' and low tan δ maximum values compared to untreated fibre composites. From swelling studies in methyl ethyl ketone it was observed that the mole percentage of uptake of the solvent by the treated fibre composites is less than that by the untreated fibre composites. From these results it can be concluded that in composites containing alkalised fibres there is enhanced interfacial adhesion between the fibre and the matrix leading to better properties, compared to untreated fibre composites.     

Effect of fiber loading and orientation on mechanical and erosion wear behaviors of glass–epoxy composites

For a composite material, its mechanical behavior and surface damage by solid particle erosion depend on many factors. One of the most important factors is the fiber content. Similarly, these properties are also greatly affected by the fiber orientation. In this work, a series of experiments were carried out to investigate the influence of fiber loading and fiber orientation on mechanical and erosion behavior of glass fiber‐reinforced epoxy composites. The composites were fabricated with three different fiber loadings (20, 30, and 40 wt%) and at four different fiber orientations (15°, 30°, 45°, and 60°). The conclusions drawn on the basis of the experimental findings are discussed, and composite with 30° fiber orientation shows better microhardness compared with other fiber orientations irrespective of fiber loading. Similar observations are also noticed for other mechanical properties of the composites, such as tensile strength, flexural strength, interlaminar shear strength, impact strength, etc. Finally, the morphology of eroded surfaces is examined using scanning electron microscopy (SEM), and possible erosion mechanisms are identified. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Influence of interfacial interactions on the properties of PVC/cellulosic fiber composites

The surface properties at the interface between thermoplastic and cellulosic fibers strongly influence the mechanical properties of plastic/cellulosic fiber composites. This paper examines the role of surface acid-base properties of plasticized PVC and cellulosic fibers on the mechanical properties of the composites. The acid-base surface characteristics of cellulosic fibers were modified by treating the fibers with γ-aminopropyltriethoxysilane (A-1100), dichlorodiethylsilane, phthalic anhydride, and maleated polypropylene. The empirical acid (K_A) and base (K_D) characteristics (i.e., electron donor/acceptor abilities) of untreated and treated fibers, as well as plasticized PVC, were determined using inverse gas chromatography (IGC) technique. These parameters were used to yield information on the acid-base pair interactions that were correlated with the tensile and notched Izod impact properties of the composites. Acid-base pair interactions have been found to be a valuable parameter in the design of surface modification strategies intended to optimize the tensile strength of the composites. By tailoring the acid-base characteristics of cellulosic fibers and plasticized PVC, a composite with equal tensile strength and greater modulus than unfilled PVC was developed. However, the acid-base factors did not correlate with tensile modulus, the elongation at break, and the notched Izod impact property of PVC/newsprint fiber composites. Aminosilane has been observed to be a suitable adhesion promoter for PVC/wood composites improving significantly the tensile strength of the composites. Other treatments (dichlorodiethylsilane, phtalic anhydride, and maleated polypropylene) were found to be ineffective, giving similar strength compared to the composites with untreated cellulosic fibers. FTIR spectroscopy results suggested that aminosilane was effective because treated cellulosic fibers can react with PVC to form chemical bonds. The resulting bond between PVC and cellulosic fibers accounts for the effectiveness of aminosilane, when compared with other coupling agents.     

Interfacial structures and mechanical properties of PVC composites reinforced by CaCO3 with different particle sizes and surface treatments

The effects of particle size and surface treatment of CaCO₃ particles on the microstructure and mechanical properties of poly(vinyl chloride) (PVC) composites filled with CaCO₃ particles via a melt blending method were studied by SEM, an AG‐2000 universal material testing machine and an XJU‐2.75 Izod impact strength machine. The tensile and impact strengths of CaCO₃/PVC greatly increased with decreasing CaCO₃ particle size, which was attributed to increased interfacial contact area and enhanced interfacial adhesion between CaCO₃ particles and PVC matrix. Titanate‐treated nano‐CaCO₃/PVC composites had superior tensile and impact strengths to untreated or sodium‐stearate‐treated CaCO₃/PVC composites. The impact strength of titanate‐treated nano‐CaCO₃/PVC composites was 26.3 ± 1.1 kJ m⁻², more than three times that of pure PVC materials. The interfacial adhesion between CaCO₃ particles and PVC matrix was characterized by the interfacial interaction parameter B and the debonding angle θ, both of which were calculated from the tensile strength of CaCO₃/PVC composites. Copyright © 2005 Society of Chemical Industry     

Preparation and characterization of poly(vinyl chloride)/virgin and treated sisal fiber composites

Mechanical property changes, thermal stability, and water absorption capacity of poly(vinyl chloride) (PVC)/sisal fiber composites were assessed with respect to the effect of maleic anhydride chemical treatments of the sisal fiber, for five different sisal fiber contents, varying from 0 to 30% by weight in the composite. The composites prepared with the untreated sisal exhibited higher tensile modulus and hardness than the unloaded resin, while elongation and tensile strength were reduced. The deterioration in the mechanical properties of PVC blended with sisal fiber is attributed to the presence of moisture, interfacial defects at the fiber and polymer interface, and fiber dispersion in the PVC matrix. The amount of absorbed water is a function of the amount of fiber in the composite (F0 = 0 phr, F5 = 0.77 phr, and F20 = 4.83 phr). The comparison of the results of characterization of F5, F20, and F30 formulations prepared with the untreated fibers and the treated ones showed a reduction in absorbed water after the chemical treatment of fiber with maleic anhydride (F0 = 0 phr, F5 = 0.28 phr, and F20 = 2.99 phr), thus improving the mechanical properties of composites prepared with the treated sisal. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3630–3636, 2007     

Green Composites from Natural Rubber and Oil Palm Fiber: Physical and Mechanical Properties

Natural rubber (NR) composites were prepared by incorporating short oil palm fibers of different lengths (viz., 2, 6, 10, and 14 mm) into natural rubber matrix in a mixing mill according to a base formulation. The curing characteristics of the mixes were studied and the samples were vulcanized at 150°C. The vulcanization parameters, processability characteristics, and tensile properties of these composites were analyzed. The effects of fiber length, orientation, loading, and fiber-matrix interaction on the mechanical properties of the green composites were studied. The reinforcement property of the alkali-treated fiber was compared with that of the untreated one. The extent of fiber orientation was studied from green strength measurements. From anisotropic swelling studies, the extent of fiber alignment and the strength of fiber–rubber interface adhesion were analyzed. Scanning electron microscopic (SEM) studies were carried out to analyze the fiber surface morphology, fiber pullout, and fiber–rubber interface.     

The effect of blending sequence on the structure and properties of poly(vinyl chloride)/chicken eggshell powder composites

The effect of the blending sequence of poly(vinyl chloride)/chicken eggshell powder (PVC/ESP) composites on the processing, mechanical properties, morphology, and thermal decomposition were investigated. The compounding of composites was done by using a Rheomix mixture internal mixer at 180°C and a rotor speed of 30 rpm for 10 min to allow the mixing torque to reach a steady state. The mechanical and morphological properties of PVC/ESP composites under different blending sequences have been characterized by a lightweight tensile tester and scanning electron microscopy. The thermal stability and thermal analysis of the composites were performed by thermogravimetric and differential scanning calorimetric analysis. Good interfacial adhesion between filler and matrix in composites prepared via blending sequence 2 has improved the tensile strength and thermal stability of the PVC/ESP composite compared with blending sequence 1 as proved from scanning electron microscopy results on the tensile fracture surface of the composites. Thermogravimetric analysis results show that blending sequence 2 exhibited higher thermal stability comparable with blending sequence 1. In addition, the differential scanning calorimetric analysis results illustrate that the composites prepared via blending sequence 2 exhibit higher melting and crystallization temperature values compared with composites prepared via blending sequence 1. J. VINYL ADDIT. TECHNOL., 23:298–304, 2017. © 2015 Society of Plastics Engineers     

Processing,Tensile, and Thermal Studies of Poly(Vinyl Chloride)/Epoxidized Natural Rubber/Kenaf Core Powder Composites with Benzoyl Chloride Treatment

The kenaf core powder (KCP) has been treated with benzoyl chloride (BC) in poly(vinyl chloride)(PVC)/epoxidized natural rubber (ENR)/KCP composites. The presence of BC grafted on KCP was evident by infrared analysis. PVC/ENR/KCP samples were prepared using Haake Polydrive with the temperature of 140°C and KCP loading of 5, 10, 15, and 20?phr. The processing, tensile and thermal properties of the composites were investigated. The enhancement of tensile properties showed that the treatment improved the interfacial adhesion between KCP with PVC/ENR matrix. Higher glass transition temperature and higher thermal stability after treatment with BC support the enhancement of the composites’ tensile properties.     

Comparative Studies of Mechanical and Interfacial Properties Between Jute Fiber/PVC and E-Glass Fiber/PVC Composites

Composites (50 wt% fiber) of jute fiber reinforced polyvinyl chloride (PVC) matrix and E-glass fiber reinforced PVC matrix were prepared by compression molding. Mechanical properties such as tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS) of both types of composites was evaluated and compared. Values of TS, TM, BS, BM and IS of jute fiber/PVC composites were found to be 45 MPa, 802 MPa, 46 MPa, 850 MPa and 24 kJ/m², respectively. It was observed that TS, TM, BS, BM and IS of E-glass fiber/PVC composites were found to increase by 44, 80, 47, 92 and 37.5%, respectively. Thermal properties of the composites were also carried out, which revealed that thermal stability of E-glass fiber/PVC system was higher. The interfacial adhesion between the fibers (jute and E-glass) and matrix was studied by means of critical fiber length and interfacial shear strength that were measured by single fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were investigated by Scanning Electron Microscopy.     

The Effect of Fiber Bleaching Treatment on the Properties of Poly(lactic acid)/Oil Palm Empty Fruit Bunch Fiber Composites

In this work, biodegradable composites from poly(lactic acid) (PLA) and oil palm empty fruit bunch (OPEFB) fiber were prepared by melt blending method. Prior to mixing, the fiber was modified through bleaching treatment using hydrogen peroxide. Bleached fiber composite showed an improvement in mechanical properties as compared to untreated fiber composite due to the enhanced fiber/matrix interfacial adhesion. Interestingly, fiber bleaching treatment also improved the physical appearance of the composite. The study was extended by blending the composites with commercially available masterbatch colorant.     

The enhancement performances of cotton stalk fiber/PVC composites by sequential two steps modification

In the present study, the cotton stalk fiber (CSF) was modified by sequential two steps of alkali and copper ethanolamine (CE) solution treatment. The unmodified and modified CSF/poly(vinyl chloride) (CSF/PVC) composites were prepared. The mechanical and physical performances of the various CSF/PVC composites were studied comparatively. By the modification of CE solution, all the tensile strength, tensile modulus, impact strength, water resistance, and heat distortion temperature of samples were enhanced continuously. The sample with comprehensive properties was obtained using 2% concentration of CE. The composites were also prepared with different CSF content. By increasing the CSF loading, all the tensile strength, elongation at breakage, tensile modulus, and heat distortion temperature of samples were enhanced. The existence of copper on the surface of CSF improved the thermal stability of the CSF/PVC composites. Water retention value, oil retention value, and scanning electron microscope were applied to reveal the components and microscopic change of the composites. The possible reaction mechanism of modification was proposed based on the experimental results and according to the previous literature. This method reported here may provide a new way for the fabrication of CSF/PVC composite in engineering applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46090.     

Fabrication and Mechanical Characterization of Jute Fabrics: Reinforced Polyvinyl Chloride/Polypropylene Hybrid Composites

Jute fabrics such as reinforced polyvinyl chloride (PVC), polypropylene (PP), and a mixture of PVC and PP matrices-based composites (50 wt% fiber) were prepared by compression molding. Tensile strength (TS), bending strength (BS), tensile modulus (TM), and vbending modulus (BM) of jute fabrics' reinforced PVC composite (50 wt% fiber) were found to be 45 MPa, 52 MPa, 0.8 GPa, and 1.1 GPa, respectively. The effect of incorporation of PP on the mechanical properties of jute fabrics' reinforced PVC composites was studied. It was found that the mixture of 60% PP and 40% PVC matrices based composite showed the best performance. TS, BS, TM, and BM for this composite were found to be 65 MPa, 70 MPa, 1.42 GPa, and 1.8 GPa, respectively. Degradation tests of the composites for up to six months were performed in a soil medium. Thermo-mechanical properties of the composites were also studied.     

The influence of fiber surface modification on the mechanical properties of coir‐polyester composites

Coir, an important lignocellulosic fiber, can be incorporated in polymers like unsaturated polyester in different ways for achieving desired properties and texture. But its high level of moisture absorption, poor wettability and insufficient adhesion between untreated fiber and the polymer matrix lead to debonding with age. In order to improve the above qualities, adequate surface modification is required. In our present work, fiber surface modification was effected through dewaxing, alkali (5%) treatment, aqueous graft copolymerization of methyl methacrylate (MMA) onto 5% alkali treated coir for different extents using CuSO₄ – NaIO₄ combination as an initiator system and cyanoexhylation with a view to improve the mechanical performance of coir‐polyester composites. Mechanical properties like tensile strength (PS), flexural strength (ES) and impact strength (IS) of the composites as a function of fiber loading and fiber surface modification have been evaluated. Composites containing z5 wt% of fiber (untreated) improved tensile and flexural strength by 30% and 27% respectively in comparison to neat polyester. The work of fracture (impact strength) of the composite with 25 wt% fiber content was found to be 967 J/m. The elongation at break of the composites exhibits an increase with the introduction of fiber, All types of surface modification result In improved mechanical properties of the composites. Significant improvement in mechanical strength was also observed for composites prepared from 5% PMMA grafted fiber.