Optimization of Curing Conditions and Nanofiller Incorporation for Production of High Performance Laminated Kevlar/Epoxy Nanocomposites

Author(s):  
Abdel-Hamid I. Mourad ◽  
Mouza S. Al Mansoori ◽  
Lamia A. Al Marzooqi ◽  
Farah A. Genena ◽  
Nizamudeen Cherupurakal

Kevlar composite materials are getting scientific interest in repairing of oil and gas pipelines in both offshore and onshore due to their unique properties. Curing is one of the major factor in deciding the final mechanical performance of laminated Kevlar/epoxy nanocomposites. The parameters such as curing time, temperature and applied pressure during the hot pressing will affect chemistry of crosslinking of the epoxy matrix and interaction of epoxy with the Kevlar fiber. The present study is carried out to evaluate the optimal curing conditions of the Kevlar/epoxy nanocomposites. Three different nanofillers (namely Multi walled Carbon nanotubes (MWCNT), Silicon Carbide (SiC) and Aluminum Oxide (Al2O3)) are incorporated in different weight percentage. Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analysis (TGA) tests are carried out to determine the thermal stability and optimal curing conditions. Mechanical performance is investigated by conducting flexure, and drop weight tests. The results show that, the optimal curing temperature for maximizing the mechanical properties is at 170°C. Peeling off the Kevlar layers are observed for nanocomposite samples cured under 100°C. Mechanical strength of the composites is enhanced by optimizing the curing conditions and nanofiller contents.

2021 ◽  
Vol 13 (24) ◽  
pp. 13887
Author(s):  
Rosa Veropalumbo ◽  
Francesca Russo ◽  
Cristina Oreto ◽  
Giovanna Giuliana Buonocore ◽  
Letizia Verdolotti ◽  
...  

In order to meet the environmental needs caused by large plastic waste accumulation, in the road construction sector, an effort is being made to integrate plastic waste with the function of polymer into asphalt mixtures; with the purpose of improving the mechanical performance of the pavement layers. This study focuses on the effect of a recycled mixture of plastic waste on the chemical, thermal, and rheological properties of designed asphalt blends and on the identification of the most suitable composition blend to be proposed for making asphalt mixture through a dry modification method. Thermo-gravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy analysis were carried out to investigate the effect of various concentrations and dimensions of plastic waste (PW) on the neat binder (NB). The frequency sweep test and the multiple stress creep and recovery test were performed to analyze the viscoelastic behavior of the asphalt blends made up of PW in comparison with NB and a commercial modified bitumen (MB). It has been observed that the presence of various types of plastic materials having different melting temperatures does not allow a total melting of PW powder at the mixing temperatures. However, the addition of PW in the asphalt blend significantly improved the aging resistance without affecting the oxidation process of the plastic compound present in the asphalt blend. Furthermore, when the asphalt blend mixed with 20% PW by the weight of bitumen is adopted into the asphalt mixture as polymer, it improves the elasticity and strengthens the mixture better than the mixture containing MB.


Author(s):  
Waleed K. Ahmed

This study presents an experimental laboratory investigation done on the Polyethylene terephthalate – PET that is used for food grade (water bottle) by mixing with ionic liquid. Both thermal and mechanical properties with a varying weight percentage of ionic liquid are investigated. Mainly, at different mixing ratios of PET-Ionic liquid of (2, 3, 5, 7 and 10%), impact of the ionic liquid on the characteristics of the PET are examined through MFI (melt flow index), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), nanoindentation methods as well as Fourier Transform Infrared (FTIR) spectroscopy. In general, the estimated results indicated that the stiffness as well as the hardness acquired from nanoindentation test for the PET blends, decrease as long as the concentration increases.


2013 ◽  
Vol 785-786 ◽  
pp. 714-717 ◽  
Author(s):  
Yi Zhou ◽  
Yong Zhu Cui ◽  
Guo Jun Liu ◽  
Li Hua Lv

An intumescent flame retardant (IFR) containing phosphorus and APP was applied to polyester fabric. The finishing process was optimized and the properties of treated fabric were characterized. The optimum process was as follows: the total dosage of IFR system was 40%, the mass ratio of phosphorus-containing flame retardants and APP was 7:3, and curing temperature was 180°C. The treated PET fabrics imparted good resistance to melt drop. Characterization of the thermo-gravimetric analysis, differential scanning calorimetry (DSC) indicated that much more residual char with intumescent structure, the incombustible gas and water were formed during combustion of flame retardant polyester fabric, whose decomposition temperature was lower compared to that of the untreated sample.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2158
Author(s):  
Nanci Vanesa Ehman ◽  
Diana Ita-Nagy ◽  
Fernando Esteban Felissia ◽  
María Evangelina Vallejos ◽  
Isabel Quispe ◽  
...  

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.


2013 ◽  
Vol 678 ◽  
pp. 203-206
Author(s):  
A. Alex John Thangapaul ◽  
V. Sherly Arpuda Kiruba ◽  
R. Nivea ◽  
T. Viji ◽  
K. Thiyagarajan ◽  
...  

Nanomaterials research has become a major attraction in the field of advanced materials research in the area of Physics, Chemistry, and Materials Science. Biocompatible and chemically stable magnetic metal oxide nanoparticles have biomedical applications that includes drug delivery, cell and DNA separation, gene cloning, magnetic resonance imaging (MRI). This research is aimed at the fabrication of magnetic cobalt oxide nanoparticles using a safe, cost effective, and easy to handle technique that is capable of producing nanoparticles free of any contamination. Nanostructured Cobalt oxide powder was prepared by sonication method using ultrasonicator. Effect of sonication for different time intervals, on the morphology of cobalt oxide nanostructures was extensively studied. The morphology of the nanorods were very much affected by the sonication time, it was found that with an increase in sonication time, the length of the nanorods seem to considerably increase at the same time an agglomeration effect comes in to action and the rods form bundle like structures. These cobalt oxide nanorods were characterized using X-ray Diffraction characterization (XRD) and it revealed a cubic structure. Weight percentage of cobalt oxide was confirmed by thermo gravimetric analysis (TGA).


2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Sakvai Mohammed Safiullah ◽  
Deivasigamani Thirumoolan ◽  
Kottur Anver Basha ◽  
K. Mani Govindaraju ◽  
Dhanraj Gopi ◽  
...  

Abstract The synthesis of copolymers from different feed ratios of N-(p-bromophenyl)-2- methacrylamide (PBPMA) and glycidyl methacrylate (GMA) was achieved by using free radical solution polymerization technique and characterized using FT-IR, 1H and 13C NMR spectroscopy. The thermal stability of the synthesized copolymers was studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the copolymer is determined by gel permeation chromatography (GPC). The corrosion performances of low nickel stainless steel specimens dip coated with different composition of copolymers were investigated in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the low nickel stainless steel surfaces. However, it is observed that the mole ratio of PBPMA and GMA plays a major role in the protective nature of the copolymer.


2019 ◽  
Vol 41 (3) ◽  
pp. 388-388
Author(s):  
Khalid Saeed Khalid Saeed ◽  
Tariq Shah and Ahmad Hassan Tariq Shah and Ahmad Hassan

Effect of graphene nanoplates (GNPs) on the properties of Nylon 6,6 (Nyl 6,6) is investigated in present study. The morphological studies presented that the GNPs were dispersed inside the Nyl 6,6 matrix. The thermo gravimetric analysis (TGA) illustrated that the thermal degradation of nanocomposites samples were started at the range of 350-393 oC, which was appreciably higher than neat Nyl 6,6 (360 oC). The differential scanning calorimetry (DSC) analyses revealed that the crystallization temperature (Tc) of GNPs/Nyl 6,6 increased as increased the addition of GNPs, which might be due to the nucleation effect of GNPs. The mechanical properties of Nyl 6,6 was enhanced by incorporation of GNPs upto the addition of an optimal quantity of filler (5%wt GNPs) into the polymer matrix. The stress yield and Young’s modulus of 5%wt GNPs/Nyl 6,6 was 96.79 and 1.54, N/nm2, respectively. Both Nyl 6,6 and nanocomposites samples were also used for the adsorption of Neutral red chloride (NRC) dye, which significantly remove the dye from the aqueous solution. The neat nylon 6,6 and GNPs (5 and 10 wt%)/Nyl 6,6 adsorbed about 88.49, 93.15, and 93.60% within 2 h, respectively.


Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2230
Author(s):  
Nontsikelelo Noxolo Tafu ◽  
Victoria A. Jideani

Moringa oleifera leaf powder (MOLP) has been identified as the most important functional ingredient owing to its rich nutritional profile and healthy effects. The solubility and functional properties of this ingredient can be enhanced through solid dispersion technology. This study aimed to investigate the effects of polyethylene glycols (PEGs) 4000 and 6000 as hydrophilic carriers and solid dispersion techniques (freeze-drying, melting, solvent evaporation, and microwave irradiation) on the crystallinity and thermal stability of solid-dispersed Moringa oleifera leaf powders (SDMOLPs). SDMOLPs were dully characterized using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The PXRD results revealed that the solid dispersions were partially amorphous with strong diffraction peaks at 2θ values of 19° and 23°. The calorimetric and thermogravimetric curves showed that PEGs conferred greater stability on the dispersions. The FTIR studyrevealed the existence of strong intermolecular hydrogen bond interactions between MOLP and PEG functional groups. MOLP solid dispersions may be useful in functional foods and beverages and nutraceutical formulations.


2021 ◽  
pp. 1-8
Author(s):  
Ching-Cheng Huang

BACKGROUND: The biologic scaffolds derived from decellularized tissues and organs have been successfully developed in a variety of preclinical and/or clinical studies. OBJECTIVE: The new decellularized liver-regenerative 3D printing biomaterials were designed and prepared for cell-based liver therapies. METHODS: An extraction process was employed to remove the tissue and cellular molecules from porcine liver via pretreatment of supercritical fluid of carbon dioxide (ScCO2). Varying porosities of the decellularized liver tissues were created using papain-containing reagent treatments after ScCO2. RESULTS: The resulting liver-regenerative 3D printing biomaterials of decellularized liver collagen scaffolds were characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, differential scanning calorimetry and scanning electron microscopy. CONCLUSIONS: The decellularized liver collagen scaffolds with good thermal stability (>150 °C) were obtained and employed as liver-regenerative 3D printing biomaterials for cell-based liver therapies.


2019 ◽  
Vol 19 (01) ◽  
pp. 1850044
Author(s):  
K. Ramachandran ◽  
P. Navaneethakrishnan ◽  
M. Sivaraja

The homogeneous and substantial dispersion of nanoparticles into base fluids is vital since the final properties of any nanolubricant are estimated by their quality of stability. This paper addresses the effect of NiO nanoparticles dispersion into SN500 lubricant oil and its nonisothermal thermo stability. The dispersion of NiO nanoparticles is achieved by ultrasonication method. The thermo stability is estimated by Thermo Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). The result shows that the thermo stability of base fluid enhances up to 0.3[Formula: see text]wt.% particle concentration then it decreases due to agglomeration of dispersed nanoparticles. The findings recommend that 0.1[Formula: see text]wt.% and 0.3[Formula: see text]wt.% of NiO-nanolubricant can be used for the temperature-dependent applications up to 200∘C.


Sign in / Sign up

Export Citation Format

Share Document