The influence of alkaline aqueous solution treatment of groundnut shell–high density polyethylene composites consist of magnesium hydroxide as flame-retardant additives was investigated. FTT daul cone calorimetry and Perkin-Elmer Diamond differential scanning calorimetry (DSC) were used to characterize flammability and thermal properties of the fabricated composites. Quanta 200ESEM was used to investigate the effect of alkaline aqueous solution treatment on the microstructure of the composites. The result obtained revealed that the alkaline treatment of the shell enhanced filler–matrix compatibility. The cone calorimetry result revealed that Mg(OH)2 has good fire retardancy characteristics on the fabricated composites as properties such as heat release rate, effective heat of combustion, mass loss rate, total smoke produced, and specific extinction area were enhanced. DSC results suggested that the additives had little impact on the melting temperature of the composite.

This study concentrated on the influence of rice husk biochar on the structural, thermal, flammable, and mechanical properties of recycled high-density polyethylene (HDPE). The percentage of rice husk biochar with recycled HDPE was varied between 10% and 40%, and the optimum percentages were found for the various properties. Mechanical characteristics were evaluated in terms of the tensile, flexural, and impact properties. Similarly, the flame retardancy of the composites was observed by means of horizontal and vertical burning tests (UL-94 tests), limited oxygen index, and cone calorimetry. The thermal properties were characterized using thermogravimetric analysis (TGA). For detailed characterization, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) tests were performed, to elaborate on the variation in properties. The composite with 30% rice husk biochar demonstrated the maximum increase in tensile and flexural strength, i.e., 24% and 19%, respectively, compared to the recycled HDPE, whereas the 40% composite showed a 22.5% decrease in impact strength. Thermogravimetric analysis revealed that the 40% rice husk biochar reinforced composite exhibited the best thermal stability, due to having the highest amount of biochar. In addition, the 40% composite also displayed the lowest burning rate in the horizontal burning test and the lowest V-1 rating in the vertical burning test. The 40% composite material also showed the highest limited oxygen index (LOI), whereas it had the lowest peak heat release rate (PHRR) value (52.40% reduced) and total heat release rate (THR) value (52.88% reduced) for cone calorimetry, when compared with the recycled HDPE. These tests proved that rice husk biochar is a significant additive for enhancing the mechanical, thermal, and fire-retardant properties of recycled HDPE.

Hazelnut husk was considered as a potential filler for thermoplastic composites. Different amounts of hazelnut husk flour and the recycled high-density polyethylene (R-HDPE) were used as the filler and polymer matrix, respectively. The composite compounds were produced using single-screw extrusion compounding, and then composite panels were prepared by hot-press compression molding. The morphological, physical, mechanical, and thermal properties, as well as the biological durability of the composites, were evaluated. The flexural and tensile modulus of the composites improved with increasing hazelnut husk filler content, whereas the physical properties, biological durability, and the flexural and tensile strengths were reduced. With the addition of a maleic anhydrite-grafted polyethylene (MAPE), the hazelnut husk filler was more finely dispersed within the polymer matrix and the degree of crystallinity was lower than that of the R-HDPE. This research revealed that hazelnut husk flour has potential for use as a filler in R-HDPE composites.

Rice husk biochar was utilized to reinforce high-density polyethylene (HDPE) and to prepare biochar/plastic composites (BPC) by the extrusion method. Morphologies, non-isothermal crystallization behavior, and mechanical properties of the composites were investigated. The SEM (scanning electron microscope) showed that HDPE was embedded into the holes of the rice husk biochar. The DSC (differential scanning calorimeter) showed that biochar could reduce the crystallization rate and the higher the content of rice husk biochar, the slower the crystallization rate. Significantly, the bending and tensile strength of BPC could reach 53.7 and 20 MPa, far beyond WPC (wood plastic composites). With the increase of filler content, BPC were still stronger than WPC, although the impact strength of BPC and WPC all showed a general decline in the trend. The strong interaction was achieved by the utilization of rice husk biochar to reinforce HDPE.

This study aimed an experimental data about the effect of physical properties of samples on the mechanical characteristics of high-density polyethylene (HDPE) used for the manufacture of preinsulated pipes for heating networks. The main waterproofing insulation material in the construction of preinsulated pipelines for heating networks is polyethylene. Outer outer casing of preinsulated pipes made of high density polyethylene (HDPE) are used as a waterproofing insulation of polyurethane foam of steel pipes manufactured in the factory. The sufficient resistances to cracking and mechanical stress, resistance to ultraviolet radiation, high density, high strength, low aging are main properties of HDPE. The study of HDPE of different manufacturers is relevant because of the aging of preinsulated pipelines with HDPE outer casing. In this study are tested physical characteristics of HDPE as a melt flow rate, density at 23°C, water content of PE80, PE100 pipe polyethylene of different world manufacturers. The best samples of HDPE and the effects of various aging factors on the properties of polyethylene are presented.

High-density polyethylene (HDPE) and natural fiber composites were prepared by melt compounding and injection molding. The influence of fiber type (i.e., pine, bagasse, rice straw, and rice husk) and the addition of coupling agents on the composite properties were investigated. The use of 30 wt% fiber enhanced the tensile and flexural properties of neat HDPE, but decreased the impact strength. The comprehensive mechanical properties of HDPE/natural fiber composites were significantly improved by the addition of 2 wt% maleated polyethylene (MAPE). The toughness was further enhanced with the use of 5 wt% maleated triblock copolymer styrene-ethylene/butylene-styrene (MASEBS). The composites had higher crystallization peak temperatures and lower crystallinity levels than neat HDPE, and their thermal stability was lower than that of HDPE. The reduced storage modulus and increased loss tangent showed that MASEBS performed as a flexibilizer in composites.

Polymers that are low-cost, lightweight, durable, and eco-friendly can be considered as one of the aims of recent research studies to solve environmental problems, especially those caused by the abundance of plastic wastes. The notable mechanical properties of such polymers could be achieved with reinforcements such as using natural fibers like hemp, sisal, wood-fiber, jute, and the focus of the study, rice husk. Using high-density polyethylene (HDPE) as the matrix, the addition of rice husk fillers was able to improve the mechanical properties of the polymer composites. However, the microstructure of the composite seems to be uneven, and voids could be observed. This must be due to disturbances or inhomogeneity in the interfacial dispersion of the filler (rice husk) and the matrix (polyethylene). This paper aims to introduce a poly (ethylene glycol) methacrylate (PEGMA) compatibilizer that can help provide stronger interfacial dispersion between the filler and matrix to improve the mechanical properties and morphology of the composite. It also offers a broader perspective regarding the possible component combinations and ratios in fabricating polyethylene which may, later on, lead to the manufacture of more efficient polyethylene-based products.

AbstractThe main objective of this research was to investigate the effect on the thermal and mechanical properties of the addition of two different compatibilizing agents, malefic anhydride‐grafted polyethylene (PE) [synthesized in a solution state (MAPE) and commercial (XA255)], to olive husk flour, high‐density polyethylene (HDPE) composites. The composites contain 30 wt % of olive husk flour and a variable proportion of compatibilizer (3, 5, and 7 wt %). The grafting reaction was followed by Fourier transform infrared, and the grafting degree was evaluated by means of titration. The effect of grafting on the thermal properties of MAPE was observed by ATG/DTG. The mechanical and thermal properties of the composite were investigated. A morphological study of the composite reveals that there is a positive effect of compatibilizing agent on interfacial bonding. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

In the quest to clean up the environment and produce economically viable materials from plastic wastes and readily available natural fibres, groundnut shell powder reinforced recycled high density polyethylene composite was prepared via two roll melt mixing and compression moulding technique. The dynamic mechanical properties of the composites such as storage modulus (E'), loss modulus (E''), and damping parameter (Tan ∂) were investigated using 242E dynamic mechanical analyzer in a temperature range from 30oC 100oC at a frequency of 1 Hz. It was found that the storage modulus of all the composites decrease with increase in temperature with composite containing 25%wt fibre having maximum E' value of 1158.47MPa compared to 1033.58MPa of the unreinforced recycled high density polyethylene. These results indicated that the thermal stability and load bearing capacity of the recycled high density polyethylene have been improved with the incorporation of groundnut shell powder. Scanning Electron micrographs showed better interfacial adhesion between treated groundnut shell powder in the polymer matrix; this explained the observed improvement in the viscoelastic properties of the composites.Keywords: Mechanical Properties, Groundnut Shell Powder, Recycled polyethylene, Viscolastic, Composites.

In-situ synthesis of high-density polyethylene (HDPE) reinforced groundnut shell particulate (GSP) composite with treated GSP within the range of 10-30 wt% at 10 wt% has been achieved. The adopted technique used in the production of the composite is melt mixing and compounding using two roll mills with a compression moulding machine. Properties such as hardness, tensile strength, impact energy and water absorption analysis were examined. The result revealed that addition of GSP increases the hardness value from 22.3 to 87 Hv. However, the tensile strength progressively decreased as the GSP increases in the HDPE. This trend arises due to the interaction between neighbouring reinforced particulate which appears to influence the matrix flow, thereby inducing embrittlement of the polymer matrix. It was also observed that water absorption rate steadily increased with an increase in the exposure time and the absorbed amount of water increases by increasing the wt% of the GSP. Analysing the obtained results, it was concluded that there were improvements in the hardness, tensile strength, impact energy and water absorption properties of the HDPE-GSP polymer composite when compared to unreinforced HDPE. On these premises, GSP was found as a promising reinforcement which can positively influence the HDPE properties of modern composites.