Epoxy composites reinforced with multi-walled carbon nanotube/poly(ethylene glycol)methylether-coated aramid fiber

2016 ◽  
Vol 36 (5) ◽  
pp. 465-471 ◽  
Author(s):  
Ayesha Kausar ◽  
Muhammad Siddiq
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Ethylene Glycol ◽  
Epoxy Resin ◽  
Aramid Fiber ◽  
Aramid Fibers ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
The Matrix ◽  
Poly Ethylene

Abstract A novel type of aramid fibers coated with poly(ethylene glycol) methyl ether (PEGME)-modified multi-walled carbon nanotubes (MWCNTs) was designed using electrophoresis. Owing to the good interaction of MWCNT-PEGME with the matrix, the coated fibers were well dispersed in epoxy resin. Thin films of epoxy/aramid-MWCNT-PEGME were prepared by placing the modified aramid fibers in molds, and the epoxy resin was infused into them. 4,4′-Diaminodiphenylmethane was dissolved in epoxy before the resin was poured over the aramid fibers coated with MWCNT-PEGME. According to fracture surface studies, the modified fibers were completely miscible with the epoxy resin and the filler was dispersed well in the space between the aramid fibers. The tensile strength of neat resin was increased from 658 to 1198 MPa in 40 wt.% of fiber-loaded epoxy/aramid-MWCNT-PEGME 40 composite. The maximum flexural strength was also found to be higher for epoxy/aramid-MWCNT-PEGME 40 (1593 MPa). The glass transition temperature (Tg) was studied using differential scanning calorimetry, in the range of 164–173°C. The tensile strength, modulus, flexural strength, and Tg of epoxy/aramid fiber composites with unmodified fibers were found to be lower than those of epoxy/aramid-MWCNT-PEGME composites.

Curing Kinetics and Rheology of Diglycidyiether of Bisphenol-A Modified by Poly(ethylene glycol) Flexible Chains

2010 ◽  
Vol 123-125 ◽  
pp. 411-414 ◽  
Author(s):  
Da Hu Yao ◽  
Kyung Bok Sun ◽  
Peng Li ◽  
Joong Hee Lee
Keyword(s):  
Ethylene Glycol ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Kinetic Parameters ◽  
Curing Kinetics ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Exponential Factor ◽  
Curing Reaction ◽  
Poly Ethylene

The curing reaction of the system bisphenol-A glycidol ether epoxy resin modified by poly (ethylene glycol) (PEO) and flexible amine (D-230) as curing agent has been studied by means of differential scanning calorimetry (DSC) and thermal scanning rheometry. The curing kinetic parameters have been calculated from the non-thermal DSC curve. The kinetic analysis suggests that the two-parameter autocatalytic model is more appropriate to describe the kinetics of the curing reaction of the system. Increasing the PU content leads to an increase in the heat of curing and has a little effect on the kinetic parameters apparent activation energy (Ea), pre-exponential factor (A), and order of the reaction (m and n). The rheological properties were measured by isothermal curing evolution. Introduction of PEO flexible chains delayed the polymerization. It has been confirmed that the introduction of PEO chains in the structure of the epoxy resin increases the mobility of the molecular segment of the epoxy networks and results in the decrease in glass transition temperature.

Thermal stability, mechanical and adsorption resistant properties of HDPE/PEG/Clay nanocomposites on exposure to electron beam

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Ahmad Mohaddespour ◽  
Seyed Javad Ahmadi ◽  
Hossein Abolghasemi ◽  
Shahryar Jafarinejad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Beam ◽  
Ethylene Glycol ◽  
Thermal Resistance ◽  
Young’S Modulus ◽  
Clay Content ◽  
Poly Ethylene Glycol ◽  
The Matrix ◽  
Poly Ethylene

AbstractThe Influence of electron beam on behaviors of high density polyethylene/poly(ethylene glycol)/organoclay nanocomposites has been studied. Nanocomposite compounds were prepared by melt intercalation method. X-ray diffraction (XRD) and transition electron microscopy (TEM) revealed the combination of nanocomposite morphology. Thermal and mechanical properties of nanocomposites were studied by using Thermogravimetric analysis (TGA), Young's modulus, tensile strength and hardness tests. The results show that at 500 KGy dose of irradiation the Young’s modulus and tensile strength values have been enhanced in comparison with pure blend by cross-linking and the surface hardness of samples raises by increasing the clay content The samples with the clay content of 5 wt% in the matrix with 500KGy dose of irradiation have shown satisfactory thermal resistance.The irradiation at high levels has degraded the nanocomposites and an optimum dose must be employed to enhance their properties. The presence of poly(ethylene glycol) as a compatibilizer has improved the dispersion of clay layers into the matrix and has enhanced the mechanical properties and thermal resistance of nanocomposites. The presence of the clay in the matrix has increased the adsorption amount of xylene and toluene into the bulk of nanocomposites and the irradiation has decreased this capacity by the dose level.

Structural engineering to control density, conformation, and bioactivity of the poly(ethylene glycol)-grafted poly(urethane urea) scaffolds

2018 ◽  
Vol 34 (2) ◽  
pp. 209-223
Author(s):  
Shideh Shaneh ◽  
Fatemeh Shokrolahi ◽  
Parvin Shokrollahi ◽  
Hamid Yeganeh ◽  
Hossein Omidian
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Ethylene Glycol ◽  
Structural Engineering ◽  
Cell Attachment ◽  
Poly Ethylene Glycol ◽  
Salt Leaching ◽  
The Matrix ◽  
Diphenyl Tetrazolium Bromide ◽  
Poly Ethylene

Poly(urethane urea) scaffolds were fabricated through combined salt leaching and solvent casting methods. The scaffolds were then functionalized via aminolysis with poly(ethylene glycol) (PEG- g-PUU). To compare its bioactivity, gelatin was also grafted onto the aminolyzed poly(urethane urea) surface (Gel- g-PUU). Chemical changes at the surface were then monitored using quantitative/qualitative methods. Grafting with both gelatin and poly(ethylene glycol) remarkably enhanced the wettability of poly(urethane urea). Proliferation of human adipose–derived mesenchymal stem cells on poly(urethane urea) and the modified poly(urethane urea)s was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay. The cell experiment results showed that both the modified poly(urethane urea)s enhanced the attachment and proliferation of human adipose–derived mesenchymal stem cells compared to pure poly(urethane urea). Based on previous reports, while a supportive role is observed at adequate poly(ethylene glycol) graft densities, cell adhesion and proliferation are inhibited at very high grafting densities. To correlate the cell data to poly(ethylene glycol) conformations, the surface tension was measured. Data on human adipose–derived mesenchymal stem cells’ attachment/proliferation and contact angle/surface free energy together showed that the grafting density of poly(ethylene glycol) was regulated by optimizing aminolysis conditions, careful selection of poly(ethylene glycol)’s molecular weight, and bulk properties of the matrix poly(urethane urea). As a result, surface overcrowding and brush conformation of the poly(ethylene glycol) chains were avoided, and human adipose–derived mesenchymal stem cell attachment and proliferation occurred on the PEG- g-PUU scaffold at a comparable level to the Gel- g-PUU.

scholarly journals Tailoring Atomoxetine Release Rate from DLP 3D-Printed Tablets Using Artificial Neural Networks: Influence of Tablet Thickness and Drug Loading

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 111
Author(s):  
Gordana Stanojević ◽  
Djordje Medarević ◽  
Ivana Adamov ◽  
Nikola Pešić ◽  
Jovana Kovačević ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Release Rate ◽  
Drug Loading ◽  
Prolonged Release ◽  
Cylindrical Shape ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
3D Printed ◽  
Artificial Neural ◽  
Poly Ethylene

Various three-dimensional printing (3DP) technologies have been investigated so far in relation to their potential to produce customizable medicines and medical devices. The aim of this study was to examine the possibility of tailoring drug release rates from immediate to prolonged release by varying the tablet thickness and the drug loading, as well as to develop artificial neural network (ANN) predictive models for atomoxetine (ATH) release rate from DLP 3D-printed tablets. Photoreactive mixtures were comprised of poly(ethylene glycol) diacrylate (PEGDA) and poly(ethylene glycol) 400 in a constant ratio of 3:1, water, photoinitiator and ATH as a model drug whose content was varied from 5% to 20% (w/w). Designed 3D models of cylindrical shape tablets were of constant diameter, but different thickness. A series of tablets with doses ranging from 2.06 mg to 37.48 mg, exhibiting immediate- and modified-release profiles were successfully fabricated, confirming the potential of this technology in manufacturing dosage forms on demand, with the possibility to adjust the dose and release behavior by varying drug loading and dimensions of tablets. DSC (differential scanning calorimetry), XRPD (X-ray powder diffraction) and microscopic analysis showed that ATH remained in a crystalline form in tablets, while FTIR spectroscopy confirmed that no interactions occurred between ATH and polymers.

Mechanical properties and hydrolytic degradation of methoxy poly(ethylene glycol)-b-poly(DL-lactide-coglycolide- co-ε-caprolactone) diblock copolymer films

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Nongnit Morakot ◽  
Jirasak Threeprom ◽  
Yodthong Baimark
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Ethylene Glycol ◽  
Diblock Copolymers ◽  
Hydrolytic Degradation ◽  
Size Exclusion ◽  
Block Length ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Poly Ethylene

AbstractBiodegradable films of methoxy poly(ethylene glycol)-b-poly(DL-lactideco- glycolide-co-ε-caprolactone) diblock copolymers (MPEG-b-PDLLGCL) were prepared by solution casting method. Effects of MPEG block length and DLL:G:CL ratio of the MPEG-b-PDLLGCL films on their mechanical properties and hydrolytic degradation were studied and discussed. It was found that the mechanical properties of films were strongly dependent on glass transition temperatures (Tg) of the diblock copolymers. The hydrolytic degradation was investigated in phosphatebuffered solution at 37°C. The degraded films were characterized using gravimetry (%water uptake and %weight loss), 1H-NMR spectroscopy, differential scanning calorimetry and size exclusion chromatography. The %weight loss of the degraded films increased and molecular weight decreased on increasing the MPEG block length and incorporating the G and CL units, according to their %water uptakes. The MPEG content of the degraded film decreased and the Tg increased with hydrolytic degradation time.

scholarly journals Polymer Electrolytes Based on Borane/Poly(ethylene glycol) Methyl Ether for Lithium Batteries

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Ali Murat Soydan ◽  
Recep Akdeniz
Keyword(s):  
Ethylene Glycol ◽  
Methyl Ether ◽  
Polymer Electrolytes ◽  
Lithium Ion ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
Poly Ethylene ◽  
Chain Lengths ◽  
Glycol Methyl Ether

This work presents a different approach to preparing polymer electrolytes having borate ester groups for lithium ion batteries. The polymers were synthesized by reaction between poly(ethylene glycol) methyl ether (PEGME) and BH3-THF complex. Molecular weight of PEGMEs was changed with different chain lengths. Then the polymer electrolytes comprising boron were prepared by doping of the matrices with CF3SO3Li at various molar ratios with respect to EO to Li and they are abbreviated as PEGMEX-B-Y. The identification of the PEGME-borate esters was carried out by FTIR and 1H NMR spectroscopy. Thermal properties of these electrolytes were investigated via thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The ionic conductivity of these novel polymer electrolytes was studied by dielectric-impedance spectroscopy. Lithium ion conductivity of these electrolytes was changed by the length of PEGME as well as the doping ratios. They exhibit approximate conductivities of 10−4 S·cm−1 at 30°C and 10−3 S·cm−1 at 100°C.

Control interfacial properties and tensile strength of glass fibre/PP composites by grafting poly(ethylene glycol) chains on glass fibre surface

RSC Advances ◽  
2015 ◽  
Vol 5 (51) ◽  
pp. 40668-40677 ◽  
Author(s):  
Zeyu Liu ◽  
Bin Hao ◽  
Yagang Zhang
Keyword(s):  
Tensile Strength ◽  
Ethylene Glycol ◽  
Glass Fibre ◽  
Interfacial Adhesion ◽  
Fibre Surface ◽  
Interfacial Properties ◽  
Poly Ethylene Glycol ◽  
Pp Composites ◽  
Poly Ethylene

The interfacial adhesion increased as the grafted PEG chains became longer.

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