scholarly journals Influence of the Thermomechanical Characteristics of Low-Density Polyethylene Substrates on the Thermoresistive Properties of Graphite Nanoplatelet Coatings

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 332
Author(s):  
Ubaldo Coscia ◽  
Angela Longo ◽  
Mariano Palomba ◽  
Andrea Sorrentino ◽  
Gianni Barucca ◽  
...  

Morphological, structural, and thermoresistive properties of films deposited on low-density polyethylene (LDPE) substrates are investigated for possible application in flexible electronics. Scanning and transmission electron microscopy analyses, and X-ray diffraction measurements show that the films consist of overlapped graphite nanoplatelets (GNP) each composed on average of 41 graphene layers. Differential scanning calorimetry and dynamic-mechanical-thermal analysis indicate that irreversible phase transitions and large variations of mechanical parameters in the polymer substrates can be avoided by limiting the temperature variations between −40 and 40 °C. Electrical measurements performed in such temperature range reveal that the resistance of GNP films on LDPE substrates increases as a function of the temperature, unlike the behavior of graphite-based materials in which the temperature coefficient of resistance is negative. The explanation is given by the strong influence of the thermal expansion properties of the LDPE substrates on the thermo-resistive features of GNP coating films. The results show that, narrowing the temperature range from 20 to 40 °C, the GNP on LDPE samples can work as temperature sensors having linear temperature-resistance relationship, while keeping constant the temperature and applying mechanical strains in the 0–4.2 × 10−3 range, they can operate as strain gauges with a gauge factor of about 48.

2015 ◽  
Vol 815 ◽  
pp. 14-18
Author(s):  
P. Santhiya ◽  
S.T. Sam ◽  
H. Kamarudin ◽  
S. Ragunathan ◽  
N.Z. Noriman ◽  
...  

The properties of blends made from low density polyethylene (LDPE) with various concentration of jackfruit seeds flour (JSF) with the presence of citric acid (CA) were investigated. The JSF content was varied from 0 to 20 wt%. The JSF were blended with LDPE by using an internal mixer (Brabender) at a temperature of 150°C. The test was carried out by using differential scanning calorimetry (DSC), with heating temperature of 100C/min. The crystallinity had improved with the presence of CA. However, the crystallinity slightly reduced with the increasing JSF content and further increased with the presence of CA.


2013 ◽  
Vol 33 (7) ◽  
pp. 579-588 ◽  
Author(s):  
S.T. Sam ◽  
H. Ismail ◽  
H.P.S. Abdul Khalil

Abstract In the present study, linear low density polyethylene (LLDPE)/soya powder blends were compatibilized with epoxidized natural rubber (ENR 50) and exposed to natural weathering. The exposure period for the blends was 1 year. It was found that the degradability of the compatibilized blends was higher than that of uncompatibilized blends. Fourier transform infrared (FTIR) spectra, the tensile test, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) were applied to analyze the degradability of the blends. IR spectra showed that the carbonyl index (CI) of the blends increased as a function of exposure period and soya powder content. The compatibilized blends gave higher carbonyl indices. The retention tensile strength and elongation at break (Eb) of the compatibilized blends after weathering was generally lower than for the uncompatibilized blends. The increase of crystallinity also indicated a reduction of the amorphous portion after degradation. The higher crystallinity in compatibilized blends further confirms the higher degradability of ENR 50 compatibilized blends. The weight loss and molecular weight change indicated that the incorporation of ENR 50 into LLDPE/soya powder blends can enhance the degradability of the blends upon outdoor exposure.


2016 ◽  
Vol 36 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Samira Sahi ◽  
Hocine Djidjelli ◽  
Amar Boukerrou

Abstract This paper illustrates the aim to introduce biodegradable vegetable filler in synthetic polymers to prepare novel biodegradable composites. Low density polyethylene/alkali treated corn flour (LDPE/ATCF) composites were prepared by reactive extrusion using a twin-screw extruder. The microstructure, thermal properties and tensile properties were evaluated and compared with virgin LDPE. The Fourier transform infrared (FTIR) spectra showed a decrease in the hydrophilic nature of corn flour (CF) after alkali treatment. Scanning electron microscopy (SEM) micrographs showed good dispersion between matrix and filler. The tensile and elongation at break decreased by increasing the filler content in the composites. However, the Young’s modulus increased with the increase in filler content. The biodegradation of composites was studied in the environment using the soil burial test for 6 months. Differential scanning calorimetry (DSC) analysis showed an increase of the melting enthalpy (ΔHm) and crystallinity of LDPE with evidence of degradation. The biodegradability of the composites was enhanced with increasing ATCF content in the matrix. This result was supported by weight loss and degraded surface of composites observed through morphological studies. From the results, we conclude that the use of ATCF as filler in LDPE reduces pollution problems. This is advantageous for both the economy and the environment.


2015 ◽  
Vol 30 (6) ◽  
pp. 855-884 ◽  
Author(s):  
AK Sudari ◽  
AA Shamsuri ◽  
ES Zainudin ◽  
PM Tahir

Three types of surfactants, specifically cationic, anionic, and nonionic, at different weight percentages were added into high-density polyethylene/low-density polyethylene/cellulose (HDPE/LDPE/cellulose) biocomposites via melt mixing. The cationic and anionic surfactants which are hexadecyltrimethylammonium bromide (HTAB) and sodium stearate (SS), respectively, were added from 4 to 20 wt%, whereas the nonionic surfactant which is sorbitan monostearate (SM) was added from 1 to 5 wt%. The mechanical testing results exhibited that the addition of HTAB increased tensile strength and tensile modulus, while SS deteriorated mechanical properties, while SM increased impact strength and tensile extension of the biocomposites. Based on the mechanical properties results, optimum weight percentages of HTAB and SM were 12 wt% and 4 wt%, respectively. The scanning electron microscopic micrographs displayed that the amount of cellulose fillers pullout decreased with the addition of HTAB, followed by SM, but it increased with SS. Fourier transform infrared spectra, X-ray diffractometer patterns, thermogravimetric analysis results, and differential scanning calorimetry thermograms have confirmed the presence of physical interactions only with the addition of HTAB and SM. Based on the results, compatibilizing effect was found in HTAB, whereas SM has not showed compatibilizing effect but instead plasticizing effect. However, neither compatibilizing nor plasticizing effect was exhibited by SS.


2013 ◽  
Vol 795 ◽  
pp. 433-437 ◽  
Author(s):  
S.T. Sam ◽  
N.Z. Noriman ◽  
S. Ragunathan ◽  
O.H. Lin ◽  
H. Ismail

Soya spent powder as an inexpensive and renewable source has been used as a filler for linear-low density polyethylene (LLDPE) in this study. Linear-low density polyethylene (LLDPE)/soya spent powder composites were prepared by using Haake internal mixer. The mixing time was 10 minutes at 150°C with rotor speed 50 rpm. Epoxidised natural rubber (ENR 50) has been used as a compatibilizer in the present study. The thermal properties of the LLDPE/soya spent powder composites with and without ENR were studied with a differential scanning calorimetry (DSC). The crystallinity of the LLDPE/soya spent powder composites decreased with increasing soya spent powder content. However, the addition of ENR 50 as a compatibilizer increased the crystallinity of the LLDPE/soya spent powder composites.


2019 ◽  
Vol 24 (3) ◽  
Author(s):  
Giovanni Barrera Torre ◽  
Guilherme Dognani ◽  
Flávio Camargo Cabrera ◽  
Júlio Cézar Alzate ◽  
José Alexandrino de Souza ◽  
...  

ABSTRACT The polymer blends obtained with residues that before were called wastes has been growing as a viable solution, allowing improvements in the mechanical properties and as sustainable alternative. This work reports the effects of blends of low-density polyethylene (LDPE) and natural rubber (NR), with sugar cane bagasse ash (SCBA) as filler, with and without polyethylene-graft-maleic anhydride (PE-g-MA) how coupling agent. The dynamic mechanical behavior and a stress-strain analysis were studied. The materials were further evaluated by differential scanning calorimetry and morphological observations. The results showed that incorporation of the PE-g-MA reduced the strain and improved the stress and the Young module of the mixtures. Moreover, the presence of SCBA increased the hardness while maintaining the tensile strength and the elongation behavior of the polymer. The results demonstrate the potential use of SCBA in the elastomer and thermoplastic mixture, free of vulcanization agents.


2014 ◽  
Vol 633-634 ◽  
pp. 413-416
Author(s):  
Kun Yuan Wang ◽  
Qiu Ju Sun ◽  
Yan Liu ◽  
Jie Lu

Diatomite was treated by titanate coupling agent and blended with low-density polyethylene (LDPE) by the method of melt-mixing blend. The performance of the blends, such as thermal behavior, mechanical property and microstructure, were analyzed with differential scanning calorimetry, thermo-gravimetric analysis, tensile strength testing and scanning electron microscopy. The results showed that influenced the crystalline behavior of LDPE phase in the blends and made the crystallization rate of LDPE phase decreased. Moreover, the thermo-decomposing temperature of the blends increased with increasing the diatomite content, diatomite significantly improved the thermal stability of the blends. Tensile strengths of the blends firstly decreased and then increased. When the diatomite content was 30%wt, the tensile strength of the blend reached to 14.6MPa. SEM photographs showed the good dispersion and interaction.


Author(s):  
Mujibur R. Khan ◽  
Hassan Mahfuz ◽  
Andreas Kyriacou

A systematic approach was undertaken to increase strength, modulus, and toughness of low density polyethylene (LDPE) filaments through infusion of functionalized CNT and ultra high molecular weight polyethylene (UHMWPE). CNTs were functionalized with OH functional groups using chemical treatment. Functionalized CNTs and UHMWPE were first dry mixed with LDPE, and filaments were then drawn using a melt extrusion process. Loading of UHMWPE varied from 8–10 wt% while that of CNT was at 2–4 wt%. LDPE has been infused first with UHMWPE, and then with both UHMWPE and CNT, and filaments were extruded. Neat LDPE filaments were also extruded as control samples. Individual filaments from each category were tested under tension according to ASTM D3379-75. In addition, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies were also conducted to measure changes in thermal and crystalline behavior. Filament tests have revealed that the tensile elongation of LDPE can be increased by about 200% with the addition of 10 wt% UHMWPE. This is however, is accompanied by a loss of about 50% ultimate tensile strength. In the next step, when 2 wt% CNTs and 8 wt% UHMWPE are added, tensile strength of the composite filament is restored to the level of neat LDPE (∼ 25 MPa) with an increase in modulus by 44% and in ultimate fracture strain by about 60% compared to that of neat LDPE. The source of improvement has been traced as formation of copolymer between LDPE and UHMWPE and strong interfacial interaction between the CNT and the polymers.


2015 ◽  
Vol 815 ◽  
pp. 9-13
Author(s):  
P. Santhiya ◽  
S.T. Sam ◽  
H. Kamarudin ◽  
S. Ragunathan ◽  
N.Z. Noriman ◽  
...  

The effects of adding hexanedioic acid (HA) into low density polyethylene (LDPE)/jackfruit seeds (JSF) blends on the properties were investigated by using differential scanning calorimetry (DSC). The influence of the crystallinity and thermal properties of HA on LDPE at various compositions was investigated. JSF was blended with LDPE by using internal mixer (Brabender) at temperature 150°C. JSF content was varied from 0 to 20 wt%. Crystallinity of the blends was significantly reduced with increasing JSF content and further increased with the presence of HA. Therefore, the crystallinity of the blends was improved with the presence of HA.


Sign in / Sign up

Export Citation Format

Share Document