scholarly journals Effect of Different Pore-Forming Additives on the Formation of PVDF Microporous Membranes for Bucky-Gel Actuator

2020 ◽  
Vol 22 (2) ◽  
pp. 107
Author(s):  
O.S. Morozov ◽  
S.S. Shachneva ◽  
B.A. Bulgakov ◽  
A.V. Babkin ◽  
A.V. Kepman
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyethylene Glycol ◽  
Ionic Conductivity ◽  
Polyvinylidene Fluoride ◽  
Dibutyl Phthalate ◽  
Fracture Strain ◽  
Degree Of Crystallinity ◽  
Solvent Evaporation Method ◽  
Electrolyte Uptake

The microporous polyvinylidene fluoride (PVDF) membranes were prepared by the solvent evaporation method using 50 wt.% of different pore-forming additives: poly(1-ethyl-3-vinylimidazolium tetrafluoroborate) (PIL-BF4), polyethylene glycol 3000 (PEG-3K) and 40000 (PEG-40K), dibutyl phthalate (DBP). The influence of used additive on morphology, porosity, degree of crystallinity, tensile properties, electrolyte uptake and ionic conductivity of the membranes were investigated. The maximum electrolyte uptake of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) was 184 wt.% for the membrane prepared with PEG-40K, however, the membrane was fragile and unsuitable for practical use. The remaining membranes showed approximately the same porosity (45‒48%) and electrolyte uptakes (169‒175%). At the same time, the membranes significantly differed in mechanical properties and ionic conductivity. The membrane prepared with PIL-BF4, unlike others, has a sponge-like structure and demonstrated high mechanical properties, namely tensile strength is 17.7 MPa and fracture strain is 132.5%. Bucky gel actuators were fabricated using membranes prepared with different additives. The blocking force of the actuators based on membranes with different additives decreased in the sequence of PIL-BF4, DBP and PEG. The actuator based on the membrane prepared with PIL-BF4 demonstrates a blocking force of 5.7 mN and a deformation of 1.35 % at 3 V DC.

Morphology, thermal and mechanical properties of electrospun polyvinylidene/polyethylene glycol composite nanofibers as form-stabilized phase change materials

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Xing Liu ◽  
Qi’an Yin ◽  
Chaoming Wang ◽  
Zhanjiang Hu ◽  
Zhengyu Cai
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyethylene Glycol ◽  
Phase Change ◽  
Melting Temperature ◽  
Latent Heat ◽  
Polyvinylidene Fluoride ◽  
Average Molecular Weight ◽  
High Mass ◽  
Strength Increase

Abstract Polyvinylidene fluoride (PVDF)/polyethylene glycol (PEG) form-stabilized composite phase change nanofibers with various mass percentage of PEG1000 (with average molecular weight of 1000) loadings were fabricated by electrospinning technique, in which PEG was served as phase change material (PCM) and PVDF as the supporting matrix to afford a mechanically strong structure. Effect of PEG1000 content on nanofiber morphology, phase transition properties, thermal stability, thermal energy storage and release performance, and mechanical properties were studied experimentally. The results showed that the incorporation of PEG1000 improved the spinning solution viscosity and high mass fraction of PEG1000 in the nanofibers led to decreased fiber diameter and melting temperature, and higher latent heat of fusion. In addition, mechanical test revealed that the fracture elongation of the electrospun PVDF/PEG composite nanofibrous membranes were initially increased with unobvious tensile strength changes, while the value of the elongation would decrease, and the tensile strength increase as the mass ratio of PVDF/PEG lower to 1:1. Furthermore, the melting temperature and maximum latent heat for PVDF/PEG were determined from DSC measurement as 51.8 °C, and 73.3 J/g, when the mass radio of PVDF/PEG was 1:1 (w/w), which was suitable utilized for thermo-regulating textiles or in heat storage devices.

scholarly journals Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongfang Qian ◽  
Zhen Zhang ◽  
Laijiu Zheng ◽  
Ruoyuan Song ◽  
Yuping Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weight Ratio ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Tissue Engineering Scaffolds ◽  
Elongation At Break ◽  
Nanofibrous Scaffolds ◽  
Two Peaks

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θof 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.

scholarly journals A Robust, Tough and Multifunctional Polyurethane/Tannic Acid Hydrogel Fabricated by Physical-Chemical Dual Crosslinking

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 239 ◽  
Author(s):  
Jie Wen ◽  
Xiaopeng Zhang ◽  
Mingwang Pan ◽  
Jinfeng Yuan ◽  
Zhanyu Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyethylene Glycol ◽  
Hydrogen Bonds ◽  
Tannic Acid ◽  
Hydroxyl Groups ◽  
Self Healing ◽  
Physical Chemical ◽  
Biomedical Field ◽  
Physical Crosslinking

Commonly synthetic polyethylene glycol polyurethane (PEG–PU) hydrogels possess poor mechanical properties, such as robustness and toughness, which limits their load-bearing application. Hence, it remains a challenge to prepare PEG–PU hydrogels with excellent mechanical properties. Herein, a novel double-crosslinked (DC) PEG–PU hydrogel was fabricated by combining chemical with physical crosslinking, where trimethylolpropane (TMP) was used as the first chemical crosslinker and polyphenol compound tannic acid (TA) was introduced into the single crosslinked PU network by simple immersion process. The second physical crosslinking was formed by numerous hydrogen bonds between urethane groups of PU and phenol hydroxyl groups in TA, which can endow PEG–PU hydrogel with good mechanical properties, self-recovery and a self-healing capability. The research results indicated that as little as a 30 mg·mL−1 TA solution enhanced the tensile strength and fracture energy of PEG–PU hydrogel from 0.27 to 2.2 MPa, 2.0 to 9.6 KJ·m−2, respectively. Moreover, the DC PEG–PU hydrogel possessed good adhesiveness to diverse substrates because of TA abundant catechol groups. This work shows a simple and versatile method to prepare a multifunctional DC single network PEG–PU hydrogel with excellent mechanical properties, and is expected to facilitate developments in the biomedical field.

In vitro evaluation of fluorocarbon leader line for use as a fabella-tibial suture

2004 ◽  
Vol 17 (01) ◽  
pp. 35-40 ◽  
Author(s):  
G. Hosgood ◽  
S. C. Kerwin ◽  
C. S. Hedlund ◽  
J. B. Metcalf ◽  
M. N. Banwell
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ethylene Oxide ◽  
Polyvinylidene Fluoride ◽  
Cruciate Ligament ◽  
Large Diameter ◽  
Surgical Techniques ◽  
Suitable Alternative ◽  
Knot Security ◽  
Ethylene Oxide Sterilization

SummaryCranial cruciate ligament rupture is a common injury in dogs, for which a variety of surgical techniques have been described. A commonly performed surgical technique is extracapsular stabilization with a lateral fabella-tibial suture (LFS) using large diameter nylon leader line (NLL). Inherent properties of NLL such as memory, low coefficient of friction, and large diameter may compromise knot security. Fluorocarbon (polyvinylidene fluoride; PVDF) has been investigated as a biomaterial for a variety of implants and is available as a high tensile strength fluorocarbon leader line (FCL). For a given tensile strength FCL is one-half the diameter of NLL. This study evaluated the force at failure, elongation, and stiffness of FCL compared to NLL for use as a LFS. The effects of steam and ethylene oxide sterilization on FCL were also evaluated. The results of this study demonstrate similar force at failure and stiffness for FCL when compared to NLL. In addition, the use of FCL may eliminate the elongation under low load observed with NLL. The mechanical properties of FCL loops were not affected by ethylene oxide sterilization. In contrast, steam sterilization caused significant detrimental effects on the mechanical properties of FCL and is not recommended. The reduced diameter and pliable feel of FCL allow for superior handling, formation of a less bulky and potentially more secure knot, and less foreign material in the region of implantation. FCL appears to be a suitable alternative material to NLL for a lateral fabella-tibial suture.

Effect of reactive and non-reactive diluents on thermal and mechanical properties of epoxy resin

2017 ◽  
Vol 30 (10) ◽  
pp. 1159-1168 ◽  
Author(s):  
Animesh Sinha ◽  
Nazrul Islam Khan ◽  
Subhankar Das ◽  
Jiawei Zhang ◽  
Sudipta Halder
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Polyethylene Glycol ◽  
Epoxy Resin ◽  
Mechanical Performance ◽  
Thermal And Mechanical Properties ◽  
Minor Variation ◽  
Reactive Diluents

The effect of reactive (polyethylene glycol) and non-reactive (toluene) diluents on thermal and mechanical properties (tensile strength, hardness and fracture toughness) of diglycidyl ether of bisphenol A epoxy resin (cured by triethylenetetramine) was investigated. The thermal stability and mechanical properties of the epoxy resin modified with reactive and non-reactive diluents at different wt% were investigated using thermo-gravimetric analyser, tensile test, hardness test and single-edge-notched bend test. A minor variation in thermal stability was observed for epoxy resin after addition of polyethylene glycol and toluene at 0.5 wt%; however, further addition of reactive and non-reactive diluents diminished the thermal stability. The addition of 10 wt% of polyethylene glycol in epoxy resin significantly enhances the tensile strength (∼12%), hardness (∼14%) and fracture toughness (∼24%) when compared to that of neat epoxy resin. In contrast, major drop in mechanical performance was observed after addition of toluene in epoxy. Furthermore, fracture surfaces were investigated under field emission scanning electron microscope to elucidate the failure mechanism.

scholarly journals Effect of Heat Drawing Process on Mechanical Properties of Dry-Jet Wet Spun Fiber of Linear Low Density Polyethylene/Carbon Nanotube Composites

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Jong Won Kim ◽  
Joon Seok Lee
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Tensile Strength ◽  
Polymer Materials ◽  
Degree Of Crystallinity ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Drawing Process ◽  
Linear Low Density Polyethylene ◽  
Crystallinity Degree

Polyethylene is one of the most commonly used polymer materials. Even though linear low density polyethylene (LLDPE) has better mechanical properties than other kinds of polyethylene, it is not used as a textile material because of its plastic behavior that is easy to break at the die during melt spinning. In this study, LLDPE fibers were successfully produced with a new approach using a dry-jet wet spinning and a heat drawing process. The fibers were filled with carbon nanotubes (CNTs) to improve the strength and reduce plastic deformation. The crystallinity, degree of orientation, mechanical properties (strength to yield, strength to break, elongation at break, and initial modulus), electrical conductivity, and thermal properties of LLDPE fibers were studied. The results show that the addition of CNTs improved the tensile strength and the degree of crystallinity. The heat drawing process resulted in a significant increase in the tensile strength and the orientation of the CNTs and polymer chains. In addition, this study demonstrates that the heat drawing process effectively decreases the plastic deformation of LLDPE.

Effect of Blowing Agent and Polyethylene Glycol on Cellular Structure and Mechanical Properties of Chloroprene Rubber

2012 ◽  
Vol 217-219 ◽  
pp. 517-521 ◽  
Author(s):  
Hong Ling Yi ◽  
Ting Wei ◽  
Lin Heng ◽  
Bai Cun Zheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Zinc Oxide ◽  
Polyethylene Glycol ◽  
Cellular Structure ◽  
Foaming Agent ◽  
Blowing Agent ◽  
Swell Ratio ◽  
Closed Cell ◽  
Chloroprene Rubber

In this paper the closed-cell sponge of chloroprene rubber(CR) were produced by foaming agent Azodicarbonamide (AC) and Oxybis (benzene sulfonyl) hydrazide (OBSH). The blend blowing agent AC/OBSH was more effective than the pure AC as it could produce chloroprene foam with greater cell porosity, more uniform and better cell distributions. The CR foam prepared with AC/OBSH had better tensile strength and tear strength than pure AC, but higher Shore C hardness. The Polyethyene glycol (PEG) modified Zinc Oxide (ZnO) could accelerate curing and foam process simultaneously. Increase the content of PEG, CR foam has bigger swell ratio, smaller cell size, and better softness.

Effect of Polyethylene Glycol (PEG) on Molten Plasticized Cellulose Acetate (CA)

2013 ◽  
Vol 830 ◽  
pp. 172-175
Author(s):  
Cheng Zhi Chuai ◽  
Zhi Zhang
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
Polyethylene Glycol ◽  
Flexural Strength ◽  
Cellulose Acetate ◽  
Flexural Modulus ◽  
Degree Of Polymerization ◽  
Maximum Elongation ◽  
Elongation At Break

Ethylene glycol (EG) and polyethylene glycol (PEG) were added as plasticizers to improve the processing performance of cellulose acetate (CA). The CA with 30% plasticizers were melted by HAAKE at 200 °C. The effects of EG and PEG (degree of polymerization in 200-800) on rheological properties and mechanical properties of CA were investigated. The results show that the plasticizing time, equilibrium torque and melt viscosity of the plasticizing system increase with the increase of PEG molecular weight, while the processing performance decreased. The tensile strength of the system decrease as the PEG molecular weight increased. The plasticizing system which contents 30% PEG-200(degree of polymerization is 200) shows the maximum elongation at break. The minimum values appeared in both flexural strength and flexural modulus in the CA/PEG-200 system.

scholarly journals Double-Crosslinked Polyurethane Acrylate for Highly Conductive and Stable Polymer Electrolyte

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2557
Author(s):  
Han-Na Kim ◽  
Kyung-Geun Kim ◽  
Yeon Uk Jeong ◽  
Sung Yeol Kim
Keyword(s):  
Mechanical Properties ◽  
Ionic Conductivity ◽  
Polymer Electrolyte ◽  
Polymer Electrolytes ◽  
Crosslinking Agent ◽  
Optimum Conditions ◽  
Polyurethane Acrylate ◽  
Electrolyte Uptake ◽  
Electrochemical Storage ◽  
Major Factors

High ionic conductivity and good stability are major factors that influence the use of polymer electrolytes in electrochemical storage and conversion devices. In this study, we present polyurethane acrylate (PUA) membranes having enhanced ionic conductivity and swelling stability by double crosslinking the polyurethane (PU) and polyacrylate (PA) compartments. The crosslinking agent concentration was varied to control their mechanical properties, swelling stability, and ionic conductivity. Under optimum conditions, the electrolyte uptake of the double-crosslinked PUA membranes without notable defects was 245%. The maximum ionic conductivity of these membranes reached 9.6 mS/cm, which was higher than those with respect to most of the previously reported PUA- or PU-based polymer electrolytes.

Mechanical Properties of Methylcellulose-Based Films Containing Stearic Acids

2013 ◽  
Vol 666 ◽  
pp. 23-26
Author(s):  
Tian Zhong ◽  
Zi Xuan Lian ◽  
Zhe Wang ◽  
Yan Qing Niu ◽  
Zhong Su Ma
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Polyethylene Glycol ◽  
Dry Matter ◽  
Smooth Curve ◽  
Polyethylene Glycol 400 ◽  
Peg 400 ◽  
Film Forming ◽  
Homogenization Methods

The effect of the homogenization conditions of the film-forming emulsions on the mechanical properties of Methylcellulose (MC)-based films containing stearic acids (SA) was studied. For this purpose, the initial emulsions were prepared in different dry matter ratios and treated by different homogenization methods. The mechanical properties, including elastic modulus (EM), tensile strength (TS) and elongation (E) became worse with the increase of the SA content. Then the mechanical properties were compared as a function of the polyethylene glycol 400 (PEG-400) contents. As a plasticizer, the increasing of PEG-400 could improved E greatly, but EM and TS both declined slightly. And finally, when homogenization conditions were more intense, EM and TS increased significantly while E showed a fairly smooth curve.

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