Fiber-reinforced High-density Polyethylene Research Articles

Erosion wear behavior of bamboo fiber-reinforced high-density polyethylene composites with nano silicon dioxide filler subjected to rotary water jet

The erosion wear behavior of bamboo fiber-reinforced high-density polyethylene (HDPE) composites with silicon dioxide (SiO2) nanoparticles filler was investigated based on the sand-carrying water (a mixture of water and garnet sand) jets (SCWJ). The composites consisted of varying weight percentage of SiO2 fillers were prepared through press molding technology. Based on the rotating water jet technique, the erosion wear performance of composites was considered with varying erosion times and shooting distances. The results showed that composites filled with SiO2 possessed better resistance to SCWJ erosion. The erosion resistance of the composites highly corresponds to their impact strength. The maximum erosion rate occurred at a shooting distance of 0.5 cm and an erosion duration of 180 s. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analysis further demonstrated that the erosive wear mechanisms mainly included the pulverization of bamboo fibers, brittle fracture of HDPE matrix, and increase in oxygen content.

The HDPE composites reinforced with waste hybrid PET/cotton fibers modified with the synthesized modifier

Abstract Large amounts of textile waste are generated every year and disposed of through landfill or incineration, leading to numerous environmental and social issues. In this study, waste hybrid polyethylene terephthalate (PET)/cotton fibers were used directly to reinforce high density polyethylene (HDPE) to prepare composites. In order to give full play to the fiber’s reinforcing characteristics, the PET/cotton fibers were further modified with the modifier using a novel synthesized tetraethyl orthosilicate/3-aminopropyl triethoxysilane (KH550)/polyethylene (PE)-g-MAH (MPE) hybrid (TMPE). Fourier transform infrared and scanning electron microscopy (SEM) confirmed that the TMPE was successfully coated on the surface of fibers. Furthermore, compared with the original and the MPE-modified fibers, the thermal stability of TMPE-modified fibers was significantly increased. SEM and mechanical test indicated that the compatibility of the modified fibers with HDPE had been significantly improved, which led to the improvement of mechanical properties. Compared with the original and MPE-modified fibers-reinforced HDPE composites, the bending strength, bending modulus, and impact strength of TMPE-modified fiber-reinforced HDPE composites were improved obviously by 31.7%, 25.7%, and 89.1%, respectively.

Effect of Fabrication Parameters on the Mechanical Properties of Water Hyacinth Fiber-Reinforced High-Density Polyethylene Composite

Effect of Fabrication Parameters on the Mechanical Properties of Water Hyacinth Fiber-Reinforced High-Density Polyethylene Composite

Structure Evolution and Hoop-Reinforcing Mechanism of Bionic-Inspired Off-Axial Glass Fiber-Reinforced High-Density Polyethylene Pipes Fabricated via Rotating Co-extrusion

Triple-layer rotating co-extrusion is employed to fabricate hoop-enhanced polyethylene composite pipes with bionic off-axial glass fiber (GF)-reinforced high-density polyethylene (HDPE) middle layer. One kind of super-“hybrid shish-kebab”-like structures formed by GFs and interfacial lamellae tend to spirally align with a fiber deviation angle of 55.7° as the rotation rate reaches 20 rpm. Encouragingly, the hoop strength and hydraulic damage resistance are improved by 25.5 and 24.1%, respectively, even with a low fiber aspect ratio, which can be attributed to the enhanced hoop loading capacity and the energy dissipation effect of crack bifurcation contributed by deviated hybrid structures. Innovatively, the relationship between processing field and structure evolution has been systematically investigated by the simulation of melt flow track, shear rate, and flow rate, indicating that fiber deviation is closely related to the shear rate. This work develops a feasible strategy with both academic value and industrial application prospect for the hoop enhancement of fiber-reinforced HDPE pressure pipes and improves its adaptability to service requirements as well.

Effect of compatibilizer and fiber loading on ensete fiber-reinforced HDPE green composites: Physical, mechanical, and morphological properties

Ensete fiber is a natural material extracted from E. ventricosum plants which is widely cultivated for food. This study is the first attempt to develop its composite by improving its compatibility with high density polyethylene (HDPE). The premixed composite constituents were melt-compounded by twin-screw extrusion and granulated. Composite plates were molded using hot-press machine. The effect of grafting maleic anhydride to HDPE and varying fiber loading on composite properties were investigated. Increasing ensete fiber loading has resulted in the composites being stiffer and harder leading to a decrease in its elongation at break. The addition of 5 wt% compatibilizer into 25 wt% ensete fiber-filled HDPE improved the fiber-matrix adhesion. Its tensile strength, flexural strength and impact absorption energy increased by nearly 43%, 46%, and 56% respectively when compared to composites with the same fiber loading and without compatibilizer. Morphological analysis from microscopic images of tensile fracture surfaces enlightened the interfacial adhesion to support these test results. The composites density, water absorption and melt flow index were also compared. The results show that ensete fiber-HDPE composite could be used as construction and building materials, low-density furniture, and moldable structures in need of design flexibility.

Finite element estimation of the effective mechanical properties of coir fiber-reinforced high-density polyethylene

Natural fibers (NFs) have gained attention as replacement of synthetic fibers due to their advantages such as eco-friendliness, nontoxicity, and they are available in nature ensuring a continuous supply of the fibers. The aim of this study is to evaluate the elastic properties of NFs-reinforced polymer composites at different volume fractions of fiber using the finite element method. A micromechanical three-dimensional representative volume element with a square packing geometry was developed for the analysis. Results from the finite element analysis were validated with selected analytical models and were found to be in agreement.

Stress relaxation performance of glass fiber-reinforced high-density polyethylene composite

The article presents a study about the stress relaxation by means of time-sensitive interfacial shear stress transfer between the interface of the fiber and matrix. The behavior of stress relaxation of glass fiber (GF)-reinforced high-density polyethylene (HDPE) composites is measured experimentally and then compared with Cox shear-lag analytical model predictions. Furthermore, the effect of supplemented interfacial interaction between the interface of the fiber and matrix is analyzed by the introduction of an interfacial coupling agent called Fusabond M603. In addition, the results showed that the stress relaxation behavior of GF-reinforced HDPE composite can be predicted by using a Cox shear-lag model. On examination, the experimental data and analytical model showed a favorable correlation which can be useful for future applications of the intended products made of polymer-based composites.

Natural fiber-reinforced high-density polyethylene composite hybridized with ultra-high molecular weight polyethylene

A great deal of research and development work has been recently conducted on natural fiber-reinforced polymer matrix composite for its abundancy, low density, excellent damping characteristic, and good mechanical properties. However, the low strength of natural fiber composite has limited its use to only low stress applications. The purpose of this work is to develop a natural fiber hybrid material with both enhanced strength and failure strain using a novel approach and study the effect of the processing temperature on its microstructure and performance. High-strength ultra-high molecular weight polyethylene fabrics are co-molded onto the surfaces of a kenaf fiber high-density polyethylene-based composite material by single-step compression molding. The status of the ultra-high molecular weight polyethylene fabrics at different processing temperatures is investigated using microscopic analysis. The tensile strength and impact strength of the hybrid material are evaluated. It is found that its tensile strength is increased by more than 90% with only 8% ultra-high molecular weight polyethylene fiber reinforcement added and its low density is maintained.

A Study on Moisture Content of Bamboo Fiber Reinforced HDPE Composite at Different Temperature

Natural fibers are becoming a competitive option as reinforcement of polymeric composite materials due to their bio-based character, good specific mechanical properties, low cost and inexhaustible supply. The aim of this study was to make the Bamboo fiber and high density polyethylene (HDPE) composite and to measure the wet loss of the composite due to removal of moisture content at 105 0C, 125 0C and 135 0C temperature. Bamboo fiber were extracted from bamboo culm and treated with 0.5 M NaOH. Bamboo fiber-reinforced HDPE composites were prepared employing melt blending technique followed by heat press molding with various weight fractions (5, 10, 30 and 40 wt. %) of the treated bamboo fiber with HDPE. A systematic investigation of the thermal behavior on the moisture content of the composites was carried out. It was observed that at 135 0C temperature more moisture removed from the composite compared to 105 0C and 125 0C temperature. It also revealed that the weight loss of the composite increased with the increase in the Bamboo fiber loading (5% to 40%).

The effect of corn varieties on the production of fiber-reinforced high-density polyethylene composites

In this study, four different varieties of corn fibers were used as the reinforcing phase to produce corn fiber polyethylene composites (CFPC). Parameters including the chemical composition, performances of the corn fibers, and the mechanical properties, physical properties, and stabilities of the CFPCs were compared and evaluated. Generally, the CFPC’s properties were greatly influenced by the chemical composition of corn fiber. The results indicated that the CFPC specimens reinforced by Huangnuo 206 fiber, a sticky corn variety, showed the best mechanical properties (with 26.6 ± 1.6 MPa of tensile strength and 46.1 ± 2.1 MPa of flexural strength; 2397.1 ± 225 MPa of tensile modulus and 3456.8 ± 283 MPa flexural modulus). In addition, there is no obvious relatedness between mechanical properties and stabilities of the CFPCs. Compared with other fibers, Jingcheng 8616, a sweet corn variety, has the highest modulus of rupture (MOR) and modulus of elasticity (MOE) retention rates.

Interfacial Properties of Bamboo Fiber-Reinforced High-Density Polyethylene Composites by Different Methods for Adding Nano Calcium Carbonate.

The focus of this study was to observe the effect of nano calcium carbonate (CaCO3) modification methods on bamboo fiber (BF) used in BF-reinforced high-density polyethylene (HDPE) composites manufactured by extrusion molding. Two methods were used to introduce the nano CaCO3 into the BF for modification; the first was blending modification (BM) and the second was impregnation modification (IM). In order to determine the effects of the modification methods, the water absorption, surface free energy and interfacial properties of the unmodified composites were compared to those of the composites made from the two modification methods. The results revealed that the percentage increase in the weight of the composite treated by nano CaCO3 decreased and that of the IMBF/HDPE composite was the lowest over the seven months of time. The results obtained by the acid-base model according to the Lewis and Owens-Wendt- Rabel-Kaelble (OWRK) equations indicated that the surface energy of the composites was between 40 and 50 mJ/m2. When compared to the control sample, the maximum storage modulus (E′max) of the BMBF/HDPE and IMBF/HDPE composites increased 1.43- and 1.53-fold, respectively. The values of the phase-to-phase interaction parameter B and the k value of the modified composites were higher than those of the unmodified composites, while the apparent activation energy Ea and interface parameter A were lower in the modified composites. It can be concluded that nano CaCO3 had an effect on the interfacial properties of BF-reinforced HDPE composites, and the interface bonding between IMBF and HDPE was greatest among the composites.

Cellulose fiber-reinforced high-density polyethylene composites—Mechanical and thermal properties

In this investigation, the thermal and mechanical properties of cellulose fibers from sugarcane bagasse reinforced with high density polyethylene composites were evaluated. Cellulose fibers were modified with hydrous Zr oxide to clean the fiber surface and improve the fibers–matrix adhesion. Composites were manufactured using a thermokinetic mixer process and the fiber content was responsible for 5, 10, 20, 30, and 40wt% in the composition. The chemical modification of the cellulose fibers with zirconium oxide was verified by FTIR analysis and the fibers’ morphological aspects by SEM. After the chemical modification, the FTIR results showed reduction of OH bonds. SEM characterization showed that the modification changed the morphology of fibers. The results show that composites reinforced with modified cellulose fibers have an improvement in the thermal and mechanical properties, when compared to the non-cellulose fibers. In addition, an enhancement on the mechanical properties of composites was found, i.e. a gain of 122.4% compared to neat polymer at 40wt.% fiber loading in Young’s modulus. The thermal properties show a slight decrease with increase of modified cellulose.

The effect of surface-treated titanium dioxide on the interfacial properties of carbon fiber-reinforced high-density polyethylene composite

The surface functionalization of titanium dioxide (TiO2) was used to modify the surface of carbon fiber (CF). The objective of this study is to improve the interlaminar shear strength and impact properties of the composites by mixing high-density polyethylene (HDPE) resin and modifying CFs. The Izod impact strength of the CF/HDPE composites increases with increasing CF content because of the high impact strength of the CF, whereas incorporation of the TiO2 increased the impact strength of the CF/HDPE composites, which may be attributed to the reinforcing effect of the TiO2 particles. Especially the surface treatment of TiO2 increases the interfacial adhesion and the thermal stability of the CF/TiO2/HDPE composite.

The three-point bending and tribological properties of surface-treated poly(p-phenylene benzobisoxazole) fiber-reinforced high-density polyethylene composite

The surface treatment of poly( p-phenylene benzobisoxazole) (PBO) fiber is to improve the interfacial adhesion of the PBO fiber-reinforced high-density polyethylene (HDPE) composite. The surface characteristics of untreated and treated PBO fiber were characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The interfacial shear strength between HDPE and PBO fiber was analyzed by measuring three-point bending properties of the composite. TPB exhibited different results due to the PBO fiber surface treatment. The results showed that the treatment of PBO fiber improved the interfacial adhesion as compared to the untreated one. The effects of PBO fiber content on tribological properties of the HDPE composites were investigated. The worn surface morphologies of HDPE composites were examined by scanning electron microscopy and the wear mechanisms were discussed. Results show that all treated PBO/HDPE have superior tribological characteristics to unfilled ones.

Properties of Abutilon theophrasti Fiber-reinforced High-density Polyethylene Composites

Chinese Abutilon theophrasti fiber (AF) ranks first in the world for yield; however, its application in the textile field is limited due to its characteristics. In this study, AF was used to reinforce high-density polyethylene (HDPE). Mechanical property tests, observations of the internal combination, creep behavior, and resistance to accelerate ultraviolet (UV) aging were conducted on these composites with different mass ratios. The results showed that the addition of the fiber could improve the impact resistance of the AF/HDPE composites. However, when the additive fiber content was > 60%, the flexural properties and resistance to creep deformation of the composites significantly decreased. Under the same conditions, the hygroscopic properties of the composites increased. After exposure to accelerated UV aging, the flexural strength of the composites decreased, but their impact resistance slightly improved. Infrared analysis demonstrated that lignin and other botanical compositions induced oxidative degradation in the composites. When the fiber-to-HDPE mass ratio was 60:40, the properties of the material were optimal.

Hole diameter effects on fiber-reinforced thermoplastic composite discs possessing distinct fiber arrays under thermal loading

This study explores the thermomechanical behavior of steel fiber-reinforced high-density polyethylene matrix thermoplastic composite (TPC) discs possessing distinct fiber arrays and the influence of circular hole diameter, upon exposure to convective air cooling loading. The discs were manufactured and their thermomechanical properties were assessed. Models of the discs for different D/ W ratios (where D is the circular hole diameter and W is the disc width) were constructed and analyzed. Two parameters, the circular-hole diameter and the fiber array configuration, were varied. Thermal stresses generated during the cooling of each disc were then determined. Residual thermal stress and equivalent plastic strain for each respective D/ W ratio were presented in graphical form, enabling evaluation and comparison. A parametric study was conducted to identify the influence of both circular hole diameter and distinct fiber reinforcement upon residual thermal stress and plastic deformation for steel fiber/TPC discs subjected to thermal loading.

Electron beam cross-linking of hybridized kenaf/pineapple leaf fiber-reinforced high-density polyethylene composite with and without cross-linking agents

Hybridized kenaf/PALF-reinforced HDPE composite was produced and characterized. Prepared hybrids were irradiated at various doses of EBI and subsequently with 1%, 2%, and 3% concentrations of vinyltri(2-methoxy ethoxy) silane and TMPTMA as cross-linking agents. The effects of EBI on the mechanical properties of treated and untreated composites were compared. Specimens without cross-linking agents were irradiated using a 2.0 MeV EB accelerator at dose range of 10, 20, 30, 40, 60, 80, and 100 kGy. Thereafter, 10 kGy was selected to irradiate specimens that were prepared with cross-linking agents. Hybrid without the addition of any cross-linking agent showed increase in tensile strength and modulus with increase in radiation dose. Flexural strength, however, showed decline at 80 and 100 kGy. Optimum impact strength was obtained in hybrid prepared without cross-linking agents and at only 10 kGy, while 20 kGy gave superior flexural modulus. Unlike in tensile strength, silane performed better as a cross-linking agent in flexural properties than TMPTMA. Additions of cross-linking agents had less significantly improved the tensile and flexural properties of the hybrid. It was clear that HDPE self-cross-linked by radiation, making silane and TMPTMA less effective. Fractured surfaces of the composites, examined by a scanning electron microscope showed good adhesion between fiber and matrix.

Short Nylon Fiber-reinforced HDPE: Melt Rheology

Short fiber-reinforced thermoplastics have generated much interest these days since fibrous materials tend to increase both mechanical and thermal properties, such as tensile strength, flexural strength, flexural modulus, heat deflection temperature, and creep resistance, and some times impact strength of thermoplastics. If the matrix and reinforcement are both based on polymers the composite are recyclable. The rheological behavior of recyclable composites based on nylon fiber-reinforced high density polyethylene (HDPE) is reported in this paper. The rheological behavior is evaluated both using a capillary rheometer and a torque rheometer. The study shows that the composite becomes pseudoplastic with fiber content and hence fiber addition does not affect processing adversely at higher shear rates. The torque rheometer data resemble that obtained from the capillary rheometer. The energy of mixing and activation energy of mixing also do not show much variation from that of HDPE alone.

Rice straw fiber-reinforced high-density polyethylene composite: Effect of fiber type and loading

Composite panels using virgin and recycled high-density polyethylene (VHDPE and RHDPE) and five types of natural fibers including four rice straw components (i.e., rice husk, rice straw leaf, rice straw stem, and whole rice straw) and wood fiber as control were made by melt compounding and compression molding. Fiber characteristics and the influences of fiber type and loading rate on HDPE crystallization behavior and composite mechanical properties were investigated. Fiber length and aspect ratio distributions for all fibers followed a lognormal distribution after milling with two parameters defining the curve location (i.e., mean fiber length/aspect ratio) and shape (i.e., mean fiber length/aspect ratio distribution). For both VHDPE and RHDPE, rice straw fiber systems had comparable mechanical properties with those of wood composites. Increase in fiber loading led to increased moduli and decreased tensile and impact strength. Composite panels with rice husk had the smallest storage moduli, but their impact strength was comparable or better than that of other straw fibers. Very little difference in mechanical properties existed among leaf, stem, and whole straw fibers. The particular recycled HDPE resin and its composites had significantly better moduli and strength properties compared to the virgin HDPE systems due to additives used during initial processing. X-ray diffraction experiments showed that introducing fiber to HDPE matrix did not change characteristic peak position, but the fiber increased crystalline thickness of HDPE system. Differential scanning calorimetry experiments showed that VHDPE had significantly larger peak heat flow during cooling run than the RHDPE, indicating higher crystallization rates for VHDPE. The use of fiber in both resin systems led to the reduced peak heat flow rate. The study showed that rice straw fibers can work well with both VHDPE and RHDPE as reinforcing filler. Future work will deal with effect of coupling treatments of the straw fibers in single phase or commingled plastics composite systems.

The Significance of Dielectric Spectroscopy in the Study of Transition Dynamics and Morphology of Transcrystallinity in Polymeric Composites

Transcrystallization, characterized by dense nucleation on the fiber surface and constrained radial crystalline growth, results in different crystalline morphology than that of the bulk. Concomitantly, it results in redistribution of the amorphous phase, generating rearrangement of the phase transition pattern. This can be identified by dynamic energy dissipation techniques such as highsensitivity dielectric spectroscopy performed in this study. Focusing on the glass transition, the dielectric properties of three sets of composites are considered, namely, aramid fiber-reinforced nylon 66, aramid fiber-reinforced poly(ether ether ketone), and ultrahigh molecular weight fiber-reinforced high-density polyethylene. This study demonstrates that dielectric spectroscopy is a unique experimental tool, highly sensitive to the presence of transcrystallinity via its effect on amorphous phase redistribution. Its sensitivity is reflected by a range of dielectric parameters, namely, the activation energy, the dielectric strength and Kirkwood correlation factor, the loss tangent, and the relaxation peak broadening. A number of composite–dielectric property combinations are presented.