High Density Polyethylene Hybrid Research Articles

High density polyethylene hybrid nanocomposites reinforced with carbon nanofiber and nanoclay

High density polyethylene hybrid nanocomposites reinforced with carbon nanofiber and nanoclay

A novel approach for preparation of nanocomposites with an excellent rigidity/deformability balance based on reinforced HDPE with halloysite

An innovative approach, designated as supported activator (SA), allows preparation of high density polyethylene (HDPE)-based highly performant hybrid materials. This procedure makes use of a nano-sized supported methylaluminoxane (MAO)-activator, based on halloysite natural nanotubes (HNT), combined with an in situ supporting concept. The new protocol when compared with a more conventional approach gives rise to higher polymerization activities as well as ultimate materials with better morphological features, greater crystallinity, thicker crystals, and highly increased stiffness. Moreover, a remarkable synergy between rigidity and toughness is attained. The Young’s modulus of a film obtained from the nanocomposite with the highest HNT content increases more than 70 % relatively to a pristine HDPE film, while retaining the limit stretching ability of pristine HDPE (more than 800%). A beneficial impact of using a high aspect ratio support such as HNT in the mechanical properties is also observed, when compared to similar HDPE hybrid materials derived from dendrimer-like silica (DS) nanospheres. Interestingly, polymerization activity, polymer features and derived properties found in the ultimate materials are less impacted by support/filler nature than by preparation method. This fact highlights the crucial role of the synthetic methodology used and corroborates the high potential of the SA route for the preparation of high-performance polyethylene-based nanocomposites with an excellent balance between stiffness and deformability.

Tensile, Flexural, and Morphological Properties of Jute/Oil Palm Pressed Fruit Fibers Reinforced High Density Polyethylene Hybrid Composites

The incorporation of materials that were formally regarded as agricultural wastes into polymeric matrix has drawn the attention of many researchers in recent years. This research focused on reinforcing high-density polyethylene (HDPE) matrix with treated jute fiber (JF)/oil palm pressed fruit fibers (OPPFF) at varying weight proportions. JF and OPPFF were cut to 2.5 mm length and were chemically treated thereafter with 1 M and 1.5 M sodium hydroxide solution respectively. The composites were produced using the compression molding technique. The morphological characterization of the fibers and composites for untreated and treated samples was studied with the aid of a scanning electron microscope (SEM). Tensile and flexural properties of the produced composite samples were also determined. From the result, the surface morphology of the fiber after treatment showed that there was obvious exposure of the fiber surface and removal of impurities as this influenced the microstructure of the composites and in turn the tensile and flexural properties. Hence, it was observed that 20 wt.% treated jute fiber addition shows the most significant enhancements in terms of tensile and flexural properties. The study exposed the effect of surface modification of JF/OPPF hybridization on HDPE matrix composite.

Understanding the influence of contact pressure on the wear performance of HDPE/multi-dimensional carbon filler based hybrid polymer nanocomposites

High Density Polyethylene (HDPE) exhibits good mechanical properties but poor resistance to wear which impedes its application in low load bearing industrial components. The current work is focused to understand the influence of contact pressure on the tribological performance of multidimensional carbon based filled HDPE hybrid nanocomposite. The novelty of the work lies in an in-depth investigation of the contact pressure which is observed to influence the wear performance of HDPE based composites and hybrids. The nanofillers of different dimensions; Nano-diamond (ND)-0D, Multiwalled Carbon Nanotubes (MWCNT)-1D and Graphite Nanoplatelets (GNP)-2D were chosen as reinforcements. The individual role of nanofillers and its response to the contact pressure and the prominent wear mechanisms exhibited thereof were studied in detail. 0.1 GNP/ND was noted to exhibit least contact pressure with highest wear resistance and the dictum was exonerated with Tanδ~0.5 confirming its damping abilities thereby pronouncing more wear resistance. The presence of ND in HDPE had strongly influenced the wear performance and it was analyzed based on electron affinity hypothesis. It was concluded that correlating contact pressure with wear volume, and related wear mechanisms of polymeric materials would be a novel contribution in the relevant field.

Physical, mechanical, thermal and morphological analysis of date palm mat (DPM) and palmyra palm fruit (PPF) fiber reinforced high density polyethylene hybrid composites

Physical, mechanical, thermal and morphological analysis of date palm mat (DPM) and palmyra palm fruit (PPF) fiber reinforced high density polyethylene hybrid composites

Evaluation of the degradation of HDPE hybrid composites using wood flour from CCA-treated poles, and recycled ceramic insulators

Waste from the maintenance of electricity distribution networks is generated every day, in repairing and replacement of components used in electricity distribution networks. Among the most dangerous residues, wood poles treated with chromated copper arsenate are distinguished by the toxicity of the chemical treatment it has been submitted to, as well as its ceramic insulators, due to the difficult recyclability of this material. Thus, an alternative may be the reuse of these components as reinforcing elements in polymeric composites. Based on this, two residues were used as fillers for the production of high-density polyethylene (HDPE) hybrid composites, wood powder, and insulating ceramic powder. Degradation by ultraviolet (UV) exposure in controlled environments of the composites was also evaluated, and toxicity tests were carried out based on the leaching of these loads with increased exposure time to degradation. Composites presented higher tensile and flexural properties than pure HDPE, and after the exposure to the UV degradation process, the composites presented fewer cracks when compared to HDPE. After exposure to the simulated degradation environment, the levels of chromium, copper, and arsenic leached were within the limits allowed by the standard that provides classification and means of disposal of these materials.

Assessment of Bulk Mechanical Properties of HDPE Hybrid Composite Filled with 1D/2D Nanofiller System

Current work reports on evaluation of bulk mechanical properties of High Density Polyethylene (HDPE) reinforced with functionalized 1D (Multi Walled Carbon Nanotubes- (MWCNTs) and 2D (hexagonal-Boron Nitride Nanoplatelets-(h-BNNPs) fillers. Mechanical mixing and injection moulding technique was used to prepare the composites. Evaluation of bulk mechanical properties like hardness, yield stress, fracture stress, impact toughness and Young`s modulus was carried out. The optimum properties were exhibited by HDPE/0.25 MWCNT/0.1 BNNP. Hardness, yield stress, fracture stress, impact toughness and Young`s modulus was observed to increase by 93.84, 80.83, 59.23, 115 and 42.05% on comparison with pure HDPE. TEM images confirm the tubular and hexagonal morphology of MWCNT and h-BNNP. It is concluded from test results that addition of MWCNT and h-BNNP into HDPE has improvised mechanical properties.

Assessment of nanoscopic dynamic mechanical properties and B-C-N triad effect on MWCNT/h-BNNP nanofillers reinforced HDPE hybrid composite using oscillatory nanoindentation: An insight into medical applications.

A thrust on improvement of different properties of polymer has taken a contemporary route with advent of nanofillers. Although several nanofillers are existent; MultiWalled Carbon Nanotubes- (MWCNTs) and h-Boron Nitride nanoplatelets-(h-BNNPs) unique combination of 1D and 2D dimensional geometry aids an advantage of B-C-N triad elemental effects on properties of tested samples. The current study aims to investigate the effects of MWCNT and h-BNNP reinforcement in High Density Polyethylene (HDPE) for high load bearing areas of medical applications requiring both elastic and viscous behavior. The results were analyzed keeping a view of its application in areas like HDPE based fracture fixation plates, acetabular cups and others. The composite and hybrid samples with different loadings were prepared after surface modification of nanofillers by mechanical mixing and molding technique. The dynamic nano-mechanical properties like storage modulus, loss modulus and tan delta were assessed for each sample during frequency swept from 10 to 220 Hz. The viscoelastic properties like hc/hm, H/E, elastic-plastic deformation were investigated and evaluated. At a frequency of 10 Hz, the storage and loss modulus of 0.1 CNT increased by 37.56% and decreased by 23.52% respectively on comparison with pure HDPE. This infers a good elastic as well as viscous behavior. Overall elastic behavior of 0.1 CNT was confirmed from tan delta evaluation. The interaction between B-C-N elemental triad had significant effect on creep strength, visco-damping property (hc/hm and H/E), elastic plastic displacement and pile-up and sink-in behavior. Highest creep strength and visco-damping property was exhibited by 0.25 CNT/0.15 BNNP hybrid. The elastic-plastic displacement of hybrid composite was noted as least, which decreased by 30% on comparison with pure HDPE. It can be inferred that presence of 1D-MWCNT and 2D-h-BNNP had significant effect on important dynamic viscoelastic and creep properties of HDPE based hybrid composites.

Evaluation of Tensile and Flexural Properties of Sisal/ Coconut Coir Reinforced with High Density Polyethylene Hybrid Composite

Evaluation of Tensile and Flexural Properties of Sisal/ Coconut Coir Reinforced with High Density Polyethylene Hybrid Composite

Press molding of a Si–HDPE hybrid lens substrate and evaluation of its infrared optical properties

A hybrid structure of single-crystal silicon (Si) and high-density polyethylene (HDPE) was developed as a new substrate for infrared lenses by using precision press molding. A thin HDPE film was used to laminate a silicon wafer and their interface was directly bonded by the silane cross-link. The HDPE film is easy to be hot-embossed to form three-dimensional surface microstructures and the silicon wafer provides a high stiffness for the hybrid substrate. The infrared (IR) optical properties of the hybrid substrate were examined by two kinds of measurements, transmittance and image sharpness. Interestingly, the transmittance measurement result shows that the IR transmittance of the hybrid substrate is higher than that of Si itself in some region of wavelength. The imaging test result shows that the hybrid substrate is capable to produce similar image quality as Si itself. These results strongly demonstrate that the developed Si–HDPE hybrid substrate is a promising alternative substrate material for IR lens.

Tensile Behavior of Sisal/Hemp Reinforced High Density Polyethylene Hybrid Composite

The study investigates the effect of reinforcing sisal and hemp fibers, either alone or simultaneous, into polymer matrix, containing 50-50 mixture of fresh and recycled HDPE, on the tensile behavior. Prior to manufacturing of composite, the fibers were chemically treated with NaOH and Maleic Anhydride (coupling agent). The tensile strength of the sisal-hemp fibers/HDPE hybrid composite is observed to be superior to single fiber (hemp/sisal) reinforced HDPE composites. The sisal fiber appears to be the primary reinforcing agent and dominates over hemp fiber in controlling the tensile strength of the hybrid composites. The tensile strength of the hybrid composite increases with increasing sisal content from 5% to 20% but decreases with increasing the content of hemp fiber 5% to 20%. The operative failure modes in the composites are observed to be fiber pull out and fiber breakage.

Relation between Microstructure and Tribological Properties of High Density Polyethylene Hybrid Composites Filled with Untreated Glass Spheres, Talc and Calcium Carbonate

In the present work, high density polyethylene based composites filled with glass spheres, talc and calcite particles were prepared. Fillers contents in the HDPE were 5, 10, 15, and 20 wt%. The mechanical, morphological and tribological properties of the polymer composites were investigated. Substantial improvements in the some mechanical properties were obtained by the addition of filler. For example, the results showed that the elasticity modulus of composites improved with increasing the filler content. The addition of fillers to the HDPE changed significantly the friction coefficient and wear rate of the composites. HDPE filled with a high level content of fillers showed higher wear rate than pure HDPE under dry sliding. The structure and properties of the composites are characterized using a scanning electron microscopy (SEM).

SiO2 reinforced HDPE hybrid materials obtained by the sol–gel method

ABSTRACTNovel high density polyethylene (HDPE)/SiO2 hybrid materials were prepared by the sol–gel process using tetraethoxysilane (TEOS). HDPE and synthesized HDPE‐g‐vinyl trimethoxysilane (VTMS) through melt grafting method was used as the raw material. The structure and thermal, mechanical properties of hybrid materials were investigated by Fourier transform infrared (FTIR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), simultaneous thermogravimetric (TG), differential thermal analysis (DTA), and tensile tests, respectively. Silica phase in the HDPE‐g‐VTMS hybrids showed a network structure and nano‐scale size. The covalent bonds between organic and inorganic phases were introduced by the HDPE‐g‐VTMS bearing trimethoxysilyl groups, which underwent hydrolytic polycondensation with TEOS. The thermal stability and mechanical properties of HDPE‐g‐VTMS hybrids were obviously improved by embedded silica networks. It was found that the silica content in the HDPE‐g‐VTMS hybrid material was linearly increased with the TEOS dosage. The formation of the HDPE‐g‐VTMS hybrid was beneficial for enhanced mechanical strength and thermal stability, in comparison with the neat HDPE. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39891.

Studies on mechanical characterization and water resistance of glass fiber/thermoplastic polymer bionanocomposites

AbstractThis experimental work is aimed at studying the performance of rice husk flour/glass fiber reinforced high density polyethylene hybrid nanocomposites. To meet this objective, the nanoclay was compounded with high density polyethylene (HDPE), rice husk flour (RF), glass fiber, and coupling agent in an internal mixer; then, the samples were fabricated by injection molding. The concentration was varied from 0 to 6 per hundred compounds for nanoclay and from 0 to 15% for glass fiber, individually. The amount of coupling agent was fixed at 2% for all formulations. The morphology, water absorption, thickness swelling, and mechanical properties of nanocomposites were evaluated as a function of nanoclay and glass fiber contents. The results indicated that both modulus and strength were improved when glass fibers were added to the composites system but impact strength and moisture absorption further decreased with the increase of glass fiber content. The morphology of the nanocomposites has been examined by using X‐ray diffraction. The morphological findings revealed that the nanocomposites formed were intercalated. The mechanical analysis showed that the biggest improvement of the tensile and flexural modulus and strengths can be achieved for the nanoclay loading at 4 per hundred compounds. However, further increasing of the loading of nanoclay resulted in a decrease of impact strength. Finally, it was found that addition of nanoclay reduced the water absorption and thickness swelling of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

TiO2 nanoparticles / high density polyethylene hybrid with bone-like mechanical properties and bioactivity

TiO2 nanoparticles / high density polyethylene hybrid with bone-like mechanical properties and bioactivity

Effect of admixed high-density polyethylene (HDPE) spheres on contraction stress and properties of experimental composites.

Additives that provide stress relief may be incorporated into dental composites to reduce contraction stress (CS). This study attempted to test the hypothesis that conventional fillers could be replaced by high-density polyethylene (HDPE) spheres in hybrid and nanofill composites to reduce CS, but with minimal effect on mechanical properties. Nanofill and hybrid composites were made from a Bis-GMA/TEGDMA resin having either all silica nanofiller or 75 wt.% strontium glass + 5 wt.% silica and replacing some of the nanofiller or the glass with 0%, 5% (hybrid only), 10% or 20 wt.% HDPE. The surface of the HDPE was either left untreated or had a reactive gas surface treatment (RGST). Contraction stress (CS) was monitored for 10 min in a tensilometer (n = 5) after light curing for 60 s at 390 mW/cm(2). Other specimens (n = 5) were light cured 40 s from two sides in a light-curing unit and aged 1 d in water before testing fracture toughness (K(Ic)), flexure strength (FS), and modulus (E). Results were analyzed by ANOVA with Tukey's multiple comparison test at p < 0.05. There was no difference between composites with RGST and untreated HDPE except for FS-10% HDPE hybrid (RGST higher). An increased level of HDPE reduced contraction stress for both types of composites. Flexure strength, modulus (hybrid only), and fracture toughness were also reduced as the concentration of HDPE increased. SEM showed evidence for HDPE debonding and plastic deformation during fracture of the hybrid composites. In conclusion, the addition of HDPE spheres reduces contraction stress in composites, either through stress relief or a reduction in elastic modulus.