scholarly journals Heat-Treated Wood Reinforced High Density Polyethylene Composites

2021 ◽  
Vol 72 (3) ◽  
pp. 219-229
Author(s):  
Kadir Karakuş ◽  
Deniz Aydemir ◽  
Gokhan Gunduz ◽  
Fatih Mengeloğlu

This study investigated the effect of untreated and heat-treated ash and black pine wood flour concentrations on the selected properties of high density polyethylene (HDPE) composites. HDPE and wood flour were used as thermoplastic matrix and filler, respectively. The blends of HDPE and wood fl our were compounded using single screw extruder and test samples were prepared through injection molding. Mechanical properties like tensile strength (TS), tensile modulus (TM), elongation at break (EatB), fl exural strength (FS), fl exural modulus (FM) and impact strength (IS) of manufactured composites were determined. Wood fl our concentrations have significantly increased density, FS, TM and FM and hardness of composites while reducing TS, EatB and IS. Heat-treated ash and black pine fl our reinforced HDPE composites had higher mechanical properties than untreated ones. Composites showed two main decomposition peaks; one coming from ash wood flour (353-370 °C) and black pine wood fl our (373-376 °C), the second one from HDPE degradation (469-490 °C). SEM images showed improved dispersion of heat-treated ash and black pine wood flour. The obtained results showed that both the untreated and heat-treated ash/black pine wood flour have an important potential in the manufacture of HDPE composites.

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 236
Author(s):  
Wanyu Liu ◽  
Yue Li ◽  
Shunmin Yi ◽  
Limin Wang ◽  
Haigang Wang ◽  
...  

To expand the use of wood plastic composites in the structural and engineering constructions applications, continuous aramid fiber (CAF) with nondestructive modification was incorporated as reinforcement material into wood-flour and high-density-polyethylene composites (WPC) by extrusion method with a special die. CAF was treated with dopamine (DPA), vinyl triethoxysilane (VTES), and DPA/VTES, respectively. The effects of these modifications on compatibility between CAF and WPCs and the properties of the resulting composites were explored. The results showed that compared with the original CAF, the adhesion strength of DPA and VTES combined modified CAF and WPCs increased by 143%. Meanwhile, compared with pure WPCs, CAF after modification increased the tensile strength, tensile modulus, and impact strength of the resulting composites by 198, 92, and 283%, respectively.


2017 ◽  
Vol 756 ◽  
pp. 35-43
Author(s):  
Martin Bednarik ◽  
Adam Skrobak ◽  
Vaclav Janostik

This study deals with the effect of high doses of ionizing beta radiation (132, 165 and 198 kGy) on mechanical properties (tensile strength, tensile modulus and elongation) of low and high density polyethylene under thermal loading. The measurement results of this study indicate that with an increasing dose of radiation grows tensile strength and modulus of low and high density polyethylene. For all examined materials were also observed changes in elongation.


BioResources ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1233-1251
Author(s):  
Jafar Ghaje Beigloo ◽  
Habibollah Khademi Eslam ◽  
Amir Hooman Hemmasi ◽  
Behzad Bazyar ◽  
Ismaeil Ghasemi

The effect of nanographene amount was evaluated relative to the physical, mechanical, thermal, and morphological features of wood-plastic composites. Composites were prepared using recycled polyethylene (high-density polyethylene), nanographene, and wood-flour. The amount of 80% of polymer matrix and 20% of wood flour, and nanographene at four weight levels of 0.5%, 1.5%, and 2.5%, were used. An internal mixture was utilized for making the samples. The results showed that with the 0.5 wt% increase of the amount of nanographene, the tensile and flexural strengths, the flexural and tensile modulus and the notched impact strength composite increased. With the addition of 2.5 wt% nanographene, these properties decreased. With the increase of the level of nanographene by 2.5 wt%, water absorption and the thickness swelling of the composite decreased. With the increase of the level of nanographene, the level of residue ash and thermal stability also increased. Scanning electron microscope images showed that the samples with 0.5 wt% nanographene had less holes and a smoother surface compared to the other samples.


2018 ◽  
Vol 777 ◽  
pp. 27-31
Author(s):  
Achmad Chafidz ◽  
Ariany Zulkania ◽  
Tintin Mutiara ◽  
Prima A. Handayani ◽  
Muhammad Rizal

In this work, high density polyethylene (HDPE)/polyvinyl alcohol (PVA) fiber composites have been fabricated via melt compounding by employing a twin-screw extruder. The resulted composites samples of four different PVA loadings (i.e. 0, 5, 10, 20 wt%) were then characterized via tensile test to investigate the effect of PVA loadings on their mechanical properties (i.e. modulus elasticity, tensile strength, toughness, and strain at break). Additionally, the surface morphologies of the composites (i.e. cryo-fractured and tensile fractured samples) were also studied by using a scanning electron microscopy (SEM). The SEM micrographs on the cryo-fractured sample showed that PVA fibers were perfectly embedded and well blended in HDPE matrix. Whereas, the SEM images of tensile-fractured samples showed that there was a fibrillation effect on the neat HDPE, while in the composites sample, there was an evident of broken fibers. Additionally, from the tensile test results, the modulus elasticity of the composites has increased by approximately 16, 39, and 81% (as compared to the neat HDPE) for PVAC-5, PVAC-10, and PVAC-20, respectively. Whereas, the toughness and strain at break of the composites have decreased.


2020 ◽  
Vol 11 ◽  
pp. 167-179 ◽  
Author(s):  
Tuba Evgin ◽  
Alpaslan Turgut ◽  
Georges Hamaoui ◽  
Zdenko Spitalsky ◽  
Nicolas Horny ◽  
...  

High-density polyethylene (HDPE)-based nanocomposites incorporating three different types of graphene nanoplatelets (GnPs) were fabricated to investigate the size effects of GnPs in terms of both lateral size and thickness on the morphological, thermal, electrical, and mechanical properties. The results show that the inclusion of GnPs enhance the thermal, electrical, and mechanical properties of HDPE-based nanocomposites regardless of GnP size. Nevertheless, the most significant enhancement of the thermal and electrical conductivities and the lowest electrical percolation threshold were achieved with GnPs of a larger lateral size. This could have been attributed to the fact that the GnPs of larger lateral size exhibited a better dispersion in HDPE and formed conductive pathways easily observable in scanning electron microscope (SEM) images. Our results show that the lateral size of GnPs was a more regulating factor for the above-mentioned nanocomposite properties compared to their thickness. For a given lateral size, thinner GnPs showed significantly higher electrical conductivity and a lower percolation threshold than thicker ones. On the other hand, in terms of thermal conductivity, a remarkable amount of enhancement was observed only above a certain filler concentration. The results demonstrate that GnPs with smaller lateral size and larger thickness lead to lower enhancement of the samples’ mechanical properties due to poorer dispersion compared to the others. In addition, the size of the GnPs had no considerable effect on the melting and crystallization properties of the HDPE/GnP nanocomposites.


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