Fabrication and electrical conducting behavior of carbon nanofiber reinforced high-density polyethylene/ polystyrene nanocomposites with low percolation threshold

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Guodong Liang ◽  
Suping Bao ◽  
Sie Chin Tjong

AbstractTernary high-density polyethylene/polystyrene/carbon nanofiber nano composites were fabricated by melt-compounding. The effect of melt compounding sequences on electrical conducting behavior of such composites was examined. Two compounding sequences were adopted in this study. Route I consisted of an initial melt mixing of HDPE and PS, followed by blending with CNFs. Route II involved an initial formation of the PS/CNF master batch, followed by blending with HDPE. The results showed that CNFs were dispersed in HDPE phase of Route I prepared HDPE/PS/CNF nanocomposites whilst they resided in PS phase of Route II formed nanocomposites. Electrical measurement showed that Route II prepared nanocomposites had a low percolation concentration of 1.1 vol% CNF.

Author(s):  
Songbo Xu ◽  
Aydar Akchurin ◽  
X. W. Tangpong ◽  
Tian Liu ◽  
Weston Wood ◽  
...  

High density polyethylene (HDPE) is widely used as bearing material in industrial application because of its low friction and high wear resistance properties. Carbon nanofiber (CNF) reinforced HDPE nanocomposites are promising materials for biomedical applications as well, such as being the bearing materials in total joint replacements. The main objective of the present study is to investigate how the wear of HDPE can be altered by the addition of either pristine or silane treated CNFs at different loading levels (0.5 wt.% and 3 wt.%). Two types of silane coating thicknesses, 2.8 nm and 46 nm, were applied on the surfaces of oxidized CNFs to improve the interfacial bonding strength between the CNFs and the matrix. The CNF/HDPE nanocomposites were prepared through melt mixing and hot-pressing. The coefficients of friction (COFs) and wear rates of the neat HDPE and CNF/HDPE nanocomposites were determined using a pin-on-disc tribometer under dry sliding conditions. The microstructures of the worn surfaces of the nanocomposites were characterized using both scanning electron microscope (SEM) and optical microscope to analyze their wear mechanisms. Compared with the neat HDPE, the COF of the nanocomposites were reduced. The nanocomposite reinforced with CNFs coated with the thicker silane coating (46 nm) at 0.5 wt.% loading level was found to yield the highest wear resistance with a wear rate reduction of nearly 68% compared to the neat HDPE.


2017 ◽  
Vol 52 (18) ◽  
pp. 2431-2442 ◽  
Author(s):  
Harun Sepet ◽  
Necmettin Tarakcioglu ◽  
RDK Misra

The main purpose of this work is to study how the morphology of nanofillers and dispersion and distribution level of inorganic nanofiller influence the impact behavior and fracture probability of inorganic filler filled industrial high-density polyethylene nanocomposites. For this study, nanoclay and nano-CaCO3 fillers–high-density polyethylene mixings (0, 1, 3, 5 wt.% high-density polyethylene) was prepared by melt-mixing method using a compounder system. The impact behavior was examined by charpy impact test, scanning electron microscopy, and probability theory and statistics. The level of the dispersion was characterized with scanning electron microscopy energy dispersive X-ray spectroscopy analysis. The results showed rather good dispersion of both of inorganic nanofiller, with a mixture of exfoliated and confined morphology. The results indicated that the impact strength of the industrial nanocomposite decreased with the increase of inorganic particulate content. The impact reliability of the industrial nanocomposites depends on the type of nanofillers and their dispersion and distribution in the matrix.


2021 ◽  
Author(s):  
Yuko Igarashi ◽  
Akihiro Sato ◽  
Hiroaki Okumura ◽  
Fumiaki Nakatsubo ◽  
Takashi Kuboki ◽  
...  

Abstract The dry-pulp direct-kneading method is an industrially viable, low-energy process to manufacture cellulose nanofiber (CNF) reinforced polymer composites, where chemically modified pulps can be nanofibrillated and dispersed uniformly in the polymer matrix during melt-compounding. In this study, cellulose fibers with different sizes, ranging from surface-fibrillated pulps with 20 µm in width to fine CNFs with 20 nm in width were prepared from softwood bleached kraft pulps (NBKPs) using a refiner and high-pressure homogenizer (HPH). These cellulose fibers were modified with alkenyl succinic anhydride (ASA), and then dried. The dried ASA-treated cellulose fibers were used as a feed material for melt-compounding in the dry-pulp direct kneading method to fabricate CNF reinforced high-density polyethylene (HDPE). When surface-fibrillated pulps were employed as a feed material, the pulps were nanofibrillated and dispersed uniformly in the HDPE matrix during the melt-compounding, and the composites had much better properties (i.e., much higher tensile modulus and strength and much lower coefficient of thermal expansion) than the composites produced using the pulps without pre-fibrillation. However, when CNFs were used as a feed material, the CNFs were shortened and agglomerated during the melt-compounding, thus deteriorating the properties of the composites. The study concludes that the pre-fibrillation of pulps had a significant impact on the morphology and properties of the composites. Unexpectedly, the surface-fibrillated pulp, which can be produced cost-effectively using a refiner at an industry scale, was a more suitable form than the CNF as a feed material for melt-compounding in the dry-pulp direct kneading method.


Author(s):  
Abdulmumin Adebisi ◽  
Tajudeen Mojisola ◽  
Umar Shehu ◽  
Muhammed Sani Adam ◽  
Yusuf Abdulaziz

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.


2020 ◽  
pp. 096739112093461
Author(s):  
WVWH Wickramaarachchi ◽  
S Walpalage ◽  
SM Egodage

Blending of two or more polymers generates a new material, which is more cost-effective than a newly synthesised material. Blending-type thermoplastic elastomer (TPE) is produced by melt-mixing of a thermoplastic with a rubber. These blends have high demands associated with excellent property combinations of the parent materials. Particulate fillers are used in the rubber and plastic industry for property modification and cost reduction. In this work, six particulate fillers, namely, calcium carbonate, barium sulphate (BaSO4), kaolin, talc, Snobrite clay and dolomite were used to develop natural rubber (NR)/high-density polyethylene (HDPE) TPE blends, and the most suitable filler for roofing application was identified. A series of NR/HDPE 20/80 blends were prepared by varying filler loading from 10 phr to 30 phr at 10 phr intervals using a Plasticorder. Mechanical properties, such as tensile strength, hardness, impact strength and tear strength, and gel content of the blends were investigated. The addition of talc, dolomite and kaolin to NR/HDPE blend showed reduced impact strength, which is the most important property for a roofing application. The other three fillers showed improved impact strength at specific loadings. The blend with 30 phr of BaSO4 was identified as the best blend, as per the overall performance.


2019 ◽  
Vol 69 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Luis Quiles‐Carrillo ◽  
Nestor Montanes ◽  
Vicent Fombuena ◽  
Rafael Balart ◽  
Sergio Torres‐Giner

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