scholarly journals Physical Effects of Radiation Modification of Biodegradable Xylitol-Based Materials Synthesized Using a Combination of Different Monomers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1041
Author(s):  
Marta Piątek-Hnat ◽  
Kuba Bomba ◽  
Janusz P. Kowalski-Stankiewicz ◽  
Jakub Pęksiński ◽  
Agnieszka Kozłowska ◽  
...  
Keyword(s):  
Enzymatic Degradation ◽  
Dicarboxylic Acids ◽  
Tensile Tests ◽  
Degradation Tests ◽  
Before And After ◽  
Radiation Modification ◽  
Physical Effects ◽  
Effects Of Radiation ◽  
Chain Lengths ◽  
Fraction Determination

There is a possibility of obtaining xylitol-based elastomers sharing common characteristics of biodegradability, thermal stability, and elastomeric behavior by using monomers with different chain-lengths. Therefore, we have synthesized eight elastomers using a combination of four different diols (ethanediol, 1.3-propanediol, 1.4-buanediol, and 1.5-pentanediol) and two different dicarboxylic acids (succinic acid and adipic acid). The obtained materials were further modified by performing e-beam treatment with a dose of 100 kGy. Materials both before and after radiation modification were tested by DSC, DMTA, TGA, tensile tests, gel fraction determination, hydrolytic and enzymatic degradation tests, 1H NMR and 13C NMR and FTIR.

scholarly journals E-Beam Effects on Poly(Xylitol Dicarboxylate-co-diol Dicarboxylate) Elastomers Tailored by Adjusting Monomer Chain Length

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1765
Author(s):  
Marta Piątek-Hnat ◽  
Kuba Bomba ◽  
Janusz P. Kowalski-Stankiewicz ◽  
Jakub Pęksiński ◽  
Agnieszka Kozłowska ◽  
...  
Keyword(s):  
Hydrolytic Degradation ◽  
Sebacic Acid ◽  
Dicarboxylic Acids ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Scanning Calorimetry ◽  
Before And After ◽  
Radiation Modification ◽  
Chain Lengths ◽  
Fraction Determination

Poly(xylitol dicarboxylate-co-diol dicarboxylate) elastomers can by synthesized using wide variety of monomers with different chain lengths. Obtained materials are all biodegradable, thermally stable elastomers, but their specific properties like glass transition temperature, degradation susceptibility, and mechanical moduli can be tailored for a specific application. Therefore, we synthesized eight elastomers using a combination of two dicarboxylic acids, namely suberic and sebacic acid, and four different diols, namely ethanediol, 1,3-propanediol, 1,4-buanediol, and 1,5-pentanediol. Materials were further modified by e-beam treatment with a dose of 100 kGy. Materials both before and after radiation modification were tested using tensile tests, gel fraction determination, 1H NMR, and 13C NMR. Thermal properties were tested by Differential Scanning Calorimetry (DSC), Dynamic Thermomechanical Analysis (DMTA) and Thermogravimetric Analysis (TGA). Degradation susceptibility to both enzymatic and hydrolytic degradation was also determined.

scholarly journals Study of the Ultraviolet Effect and Thermal Analysis on Polypropylene Nonwoven Geotextile

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1080
Author(s):  
Clever Aparecido Valentin ◽  
Marcelo Kobelnik ◽  
Yara Barbosa Franco ◽  
Fernando Luiz Lavoie ◽  
Jefferson Lins da Silva ◽  
...  
Keyword(s):  
Uv Light ◽  
Polymeric Materials ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Material Stiffness ◽  
Before And After ◽  
Electron Microscopy Analysis ◽  
Physical Tests ◽  
Nonwoven Geotextile

The use of polymeric materials such as geosynthetics in infrastructure works has been increasing over the last decades, as they bring down costs and provide long-term benefits. However, the aging of polymers raises the question of its long-term durability and for this reason researchers have been studying a sort of techniques to search for the required renewal time. This paper examined a commercial polypropylene (PP) nonwoven geotextile before and after 500 h and 1000 h exposure to ultraviolet (UV) light by performing laboratory accelerated ultraviolet-aging tests. The state of the polymeric material after UV exposure was studied through a wide set of tests, including mechanical and physical tests and thermoanalytical tests and scanning electron microscopy analysis. The calorimetric evaluations (DSC) showed distinct behaviors in sample melting points, attributed to the UV radiation effect on the aged samples. Furthermore, after exposure, the samples presented low thermal stability in the thermomechanical analysis (TMA), with a continuing decrease in their thicknesses. The tensile tests showed an increase in material stiffness after exposition. This study demonstrates that UV aging has effects on the properties of the polypropylene polymer.

Comparative study of thermoplastic liner materials with regard to mechanical and permeation barrier properties before and after cyclic thermal aging

2021 ◽  
Vol 63 (4) ◽  
pp. 311-316
Author(s):  
Simon Backens ◽  
Jan Siering ◽  
Stefan Schmidt ◽  
Nikolai Glück ◽  
Wilko Flügge
Keyword(s):  
Thermal Aging ◽  
Barrier Properties ◽  
Tensile Tests ◽  
Polyamide 6 ◽  
Pressure Vessels ◽  
Cross Linking ◽  
Polyamide 12 ◽  
Type Iv ◽  
Before And After ◽  
Permeation Properties

Abstract Lightweight pressure vessels of type IV for hydrogen storage consist of a thermoplastic inner liner, commonly from polyethylene or polyamide. The liner is the permeation barrier against the compressed gas and must prevent the formation of cracks, also after temperature changes, for example after refueling processes. In the present work high-density polyethylene, cross-linked polyethylene, polyamide 6 and polyamide 12 were characterized by tensile tests, single notch impact tests and permeations measurements before and after a cyclic thermal aging process. The aging only lead to slight changes of mechanical properties due to post-crystallization, but to a significant decrease of permeation properties. This decrease was contributed to weakened, amorphous regions where chain splitting occurred. Considerable differences in properties resulted from different peroxide cross-linking times of polyethylene at the same temperature. A longer holding time at 200 °C led to an improvement in impact strength by a factor of more than three. However, the permeation properties decreased by about 50 %, indicating that peroxide cross-linking in the melt inhibited the formation of crystalline regions.

scholarly journals Tensile Testing with Cyclic Strain Holding to Analyze Dynamic Recrystallization of Pure Lead

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Mayu Muramatsu ◽  
Motomichi Koyama ◽  
Ikumu Watanabe
Keyword(s):  
Dynamic Recrystallization ◽  
Tensile Testing ◽  
Cyclic Strain ◽  
Tensile Tests ◽  
Pure Lead ◽  
Factors Affecting ◽  
Before And After ◽  
Dynamic Recrystallization Behavior ◽  
The Difference ◽  
Strain Responses

We analyzed the dynamic recrystallization of pure lead by tensile testing with cyclic strain holding at room temperature. The specimens were held at an identical strain and subsequently reloaded, providing the strength before and after the strain holding process. The difference in strength enables factors affecting dynamic recrystallization behavior to be analyzed through mechanical testing. For instance, the effects of strain rate on dynamic recrystallization were analyzed by comparing the results obtained from tensile tests with and without strain holding. This experimental technique demonstrated some parts of contribution of elastic strain, dynamic recovery, dynamic recrystallization, and necking to stress-strain responses.

scholarly journals MICROSTRUCTURE RESEARCH OF THE UNIDIRECTIONAL ORGANOPLASTIC BASED ON RUSAR-NT ARAMID FIBERS AND EPOXY-POLYSULFONE BINDER

2020 ◽  
pp. 19-26
Author(s):  
E.N. Kablov ◽  
◽  
G.S. Kulagina ◽  
G.F. Zhelezina ◽  
S.L. Lonskii ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Material ◽  
Polymer Matrix ◽  
Packing Density ◽  
Tensile Tests ◽  
Polymer Composite Material ◽  
Aramid Fibers ◽  
Before And After ◽  
Binder Structure

This paper studies a polymer composite material - a unidirectional organoplastic based on Rusar-NT aramid fiber and a melt epoxy-polysulfone binder. Organoplastic has the following mechanical properties: tensile strength 2060 MPa, Young's modulus 101 GPa. The microstructure of the fiber and the polymer matrix in the organoplastic samples was studied before and after tensile tests. The features of the formation of the binder structure depending on the packing density of the fibers in organoplastics have been determined. The nature of the destruction of fibers and polymer matrix caused by the uniaxial tension has been studied.

INCREASING THE RESISTANCE OF THE ELECTRONIC COMPONENT BASE TO THE DOSE EFFECTS OF RADIATION EXPOSURE

2021 ◽  
Vol 14 (1) ◽  
pp. 16-22
Author(s):  
Aleksandr Kozyukov ◽  
Konstantin Zolnikov ◽  
Sergey Mescheryakov ◽  
Artem Groshev ◽  
Dmitriy Sysoev
Keyword(s):  
Radiation Exposure ◽  
Technological Process ◽  
Electronic Component ◽  
Transfer Characteristics ◽  
Dose Effects ◽  
Before And After ◽  
Effects Of Radiation ◽  
Process Graphs

The article considers the issues of increasing the resistance of the electronic component base (ECB) to dose effects due to the improvement of the technological process. Graphs of the functions of the transfer characteristics of MOSFETs and CMOS inverters before and after radiation exposure are presented. The effect of the charge in the oxide and on the surface formed under the action of radiation is shown.

scholarly journals Effects of Micro-Braiding and Co-Wrapping Techniques on Characteristics of Flax/Polypropylene-Based Hybrid Yarn: A Comparative Study

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2559
Author(s):  
Wenqian Zhai ◽  
Peng Wang ◽  
Xavier Legrand ◽  
Damien Soulat ◽  
Manuela Ferreira
Keyword(s):  
Mechanical Characteristics ◽  
Tensile Tests ◽  
Strong Impact ◽  
Mass Ratio ◽  
Cover Factor ◽  
Hybrid Yarn ◽  
Before And After ◽  
Treatment Agent ◽  
Production Techniques ◽  
Yarn Production

Micro-braiding and co-wrapping techniques have been developed over a few decades and have made important contributions to biocomposites development. In this present study, a set of flax/polypropylene (PP) micro-braided and co-wrapped yarns was developed by varying different PP parameters (PP braiding angles and PP wrapping turns, respectively) to get different flax/PP mass ratios. The effects on textile and mechanical characteristics were studied thoroughly at the yarn scale, both dry- and thermo-state tensile tests were carried out, and tensile properties were compared before and after the braiding process to study the braidabilities. It was observed that PP braiding angles of micro-braided yarn influenced the frictional damage on surface treatment agent of flax roving, the cohesive effect between PP filaments/flax roving, and the PP cover factor; PP wrapping turns of co-wrapped yarn had a strong impact on the flax roving damage and the PP coverage, which further influenced the characteristics. Micro-braided yarn and co-wrapped yarn with the same flax/PP mass ratio were compared to evaluate the two different hybrid yarn production techniques; it was proven that micro-braided yarn presented better performance.

scholarly journals Data on tensile tests and NMR measurements of poly(vinilidene fluoride) before and after stress relaxation

Data in Brief ◽  
2018 ◽  
Vol 19 ◽  
pp. 55-58 ◽  
Author(s):  
Maria Marjorie Contreras ◽  
Christine Rabello Nascimento ◽  
Roberto Pinto Cucinelli Neto ◽  
Marysilvia F. Costa ◽  
Celio A. Costa
Keyword(s):  
Stress Relaxation ◽  
Tensile Tests ◽  
Before And After

scholarly journals Transformation Mechanisms of Chemical Ingredients in Steaming Process of Gastrodia elata Blume

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3159 ◽  
Author(s):  
Yun Li ◽  
Xiao-Qian Liu ◽  
Shan-Shan Liu ◽  
Da-hui Liu ◽  
Xiao Wang ◽  
...  
Keyword(s):  
Enzymatic Degradation ◽  
Chemical Constituents ◽  
Relative Content ◽  
Ester Bond ◽  
Gastrodia Elata ◽  
Before And After ◽  
Transformation Mechanisms ◽  
First Time ◽  
Hydroxybenzyl Alcohol ◽  
Tof Ms

To explore the transformation mechanisms of free gastrodin and combined gastrodin before and after steaming of Gastrodia elata (G. elata), a fresh G. elata sample was processed by the traditional steaming method prescribed by Chinese Pharmacopoeia (2015 version), and HPLC-ESI-TOF/MS method was used to identify the chemical composition in steamed and fresh G. elata. Finally, 25 components were identified in G. elata based on the characteristic fragments of the compounds and the changes of the 25 components of fresh and steamed G. elata were compared by the relative content. Hydrolysis experiments and enzymatic hydrolysis experiments of 10 monomer compounds simulating the G. elata steaming process were carried out for the first time. As a result, hydrolysis experiments proved that free gastrodin or p-hydroxybenzyl alcohol could be obtained by breaking ester bond or ether bond during the steaming process of G. elata. Enzymatic experiments showed that steaming played an important role in the protection of gastrodin, confirming the hypothesis that steaming can promote the conversion of chemical constituents of G. elata—inhibiting enzymatic degradation. This experiment clarified the scientific mechanism of the traditional steaming method of G. elata and provided reference for how to apply G. elata decoction to some extent.

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