scholarly journals Synthesis, Properties, and Biodegradation of Sequential Poly(Ester Amide)s Containing γ-Aminobutyric Acid

2020 ◽  
Vol 21 (10) ◽  
pp. 3674 ◽  
Author(s):  
Yuushou Nakayama ◽  
Kazumasa Watanabe ◽  
Ryo Tanaka ◽  
Takeshi Shiono ◽  
Norioki Kawasaki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Decomposition ◽  
Monomer Unit ◽  
Dicarboxylic Acids ◽  
Aminobutyric Acid ◽  
High Melting ◽  
Thermal And Mechanical Properties ◽  
Melting Temperatures ◽  
Synthesis Properties ◽  
Derivatives Of

Poly(ester amide)s are attracting attention because they potentially have excellent thermal and mechanical properties as well as biodegradability. In this study, we synthesized a series of novel poly(ester amide)s by introducing γ-aminobutyric acid (GABA) regularly into polyesters, and investigated their properties and biodegradabilities. GABA is the monomer unit of biodegradable polyamide 4 (PA4). The new poly(ester amide)s were synthesized from the reaction of ammonium tosylate derivatives of alkylene bis(γ-aminobutylate) and p-nitrophenyl esters of dicarboxylic acids. All the obtained polymers showed relatively high melting temperatures (Tm). Their thermal decomposition temperatures were improved in comparison with that of PA4 and higher enough than their Tm. The poly(ester amide)s exhibited higher biodegradability in seawater than the corresponding homopolyesters. Their biodegradabilities in activated sludge were also studied.

Thermal stress analysis of in-plane two-directional functionally graded plates subjected to in-plane edge heat fluxes

2016 ◽  
Vol 232 (8) ◽  
pp. 693-716
Author(s):  
MK Apalak ◽  
MD Demirbas
Keyword(s):  
Mechanical Properties ◽  
Thermal Stress ◽  
Functionally Graded ◽  
Heat Fluxes ◽  
Material Composition ◽  
Stress Distributions ◽  
Thermal And Mechanical Properties ◽  
Functionally Graded Plates ◽  
Spatial Derivatives ◽  
Derivatives Of

This study investigates the thermal stress and deformation states of bi-directional functionally graded clamped plates subjected to constant in-plane heat fluxes along two ceramic edges. The material properties of the functionally graded plates were assumed to vary with a power law along two in-plane directions not through the plate thickness direction. The spatial derivatives of thermal and mechanical properties of the material composition were considered, and the effects of the bi-directional composition variations and spatial derivative terms on the displacement, strain and stress distributions were also investigated. The heat conduction and Navier equations describing the two-dimensional thermo-elastic problem were discretized using finite-difference method, and the set of linear equations were solved using the pseudo singular value method. The compositional gradient exponents and the spatial derivatives of thermal and mechanical properties of the material composition were observed to play an important role especially on the heat transfer durations, the displacement and strain distributions, but had a minor effect on the temperature and stress distributions.

Influence of Bagasse Carboxymethyl Cellulose Addition on the Thermal and Mechanical Properties of PLA Composites

2013 ◽  
Vol 747 ◽  
pp. 157-161
Author(s):  
S. Kamthai ◽  
Rathanawan Magaraphan
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Tensile Strength ◽  
Carboxymethyl Cellulose ◽  
Room Temperature ◽  
Environmental Concern ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Bagasse Waste

According to the availability of bagasse waste and increasing environmental concern, this research is focused on the preparation of polylactic acid (PLA)/bagasse carboxymethyl cellulose (CMCB) composite in order to improve the thermal and mechanical properties of PLA/CMCB film. PLA were mixed with CMCB at different ratios (1, 2, 4 and 8%, w/w of PLA), by kneading in two roll mills and then hot pressing into film. The results revealed that the addition of CMCB had significant effects on PLA composites properties. Differential scanning calorimetry (DSC) measurement indicated that the presence of CMCB accelerated the reduction of glass transition, and melting temperatures. Moreover the CMCB could improve the storage modulus of PLA composites at high temperature because its cold crystallization was developed. At room temperature, the tensile strength and elongation of PLA composite (but not modulus) were not significantly different with an increase of CMCB contents.

Arginine derivatives of dicarboxylic acids from toad venom — New agonists of ionotropic γ-aminobutyric acid receptors

Toxicon ◽  
2019 ◽  
Vol 159 ◽  
pp. S24
Author(s):  
D.S. Lebedev ◽  
I.A. Ivanov ◽  
E.V. Kryukova ◽  
V.G. Starkov ◽  
V.I. Tsetlin ◽  
...  
Keyword(s):  
Dicarboxylic Acids ◽  
Aminobutyric Acid ◽  
Toad Venom ◽  
Derivatives Of

scholarly journals Effect of processing temperatures on the thermal and mechanical properties of leather waste-ABS composites

2021 ◽  
Vol 30 ◽  
pp. 263498332110600
Author(s):  
Macaulay M. Owen ◽  
Emmanuel O. Achukwu ◽  
Innocent O. Arukalam ◽  
Mustakim Muhammad ◽  
Ahmad Z. Romli
Keyword(s):  
Mechanical Properties ◽  
Acrylonitrile Butadiene Styrene ◽  
Processing Temperature ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Melting Temperatures ◽  
Leather Wastes ◽  
Scanning Electron ◽  
Butadiene Styrene

The effect of varying processing temperatures (200, 220 and 240°C) on the thermal and mechanical properties of uncoated and epoxy-coated chrome-tanned leather wastes-ABS composites has been studied. The results obtained showed that the mechanical properties of the composites decreased as the processing temperature increased. Epoxy-coated leather wastes fibre-ABS (CLWABS) composite yielded better mechanical properties compared to the uncoated leather wastes-ABS composite (LWABS). These results were obtained at an optimized processing temperature of 200°C. Furthermore, the results were confirmed by the field emission scanning electron microscopy (FESEM) studies. The differential scanning calorimetry (DSC) studies revealed that the epoxy-coated leather wastes fibres (CLW) showed higher onset and melting temperatures of 131.8 and 179.35°C than the uncoated leather wastes fibres (LW) with glass transition (Tg) and melting (Tm) temperatures of 128.2 and 169.4°C, respectively. When the LW and CLW fibres were mixed with Acrylonitrile butadiene styrene (ABS), the Tg and Tm of CLWABS composite were found to be 94.9 and 269.8°C, respectively, higher than the LWABS composite with Tg and Tm of 89.1 and 261.6°C, respectively. Thus, this study has demonstrated that utilization of epoxy-coated chrome-tanned leather wastes fibres as fillers in the design of ABS-based composites will help a great deal in addressing the problem of solid waste pollutants in our environment.

scholarly journals Conducting polymers: a comprehensive review on recent advances in synthesis, properties and applications

RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5659-5697 ◽  
Author(s):  
Namsheer K ◽  
Chandra Sekhar Rout
Keyword(s):  
Mechanical Properties ◽  
Electrical Property ◽  
Conducting Polymers ◽  
Inorganic Materials ◽  
Environmental Stability ◽  
Comprehensive Review ◽  
Recent Advances ◽  
Synthesis Properties

Conducting polymers are extensively studied due to their outstanding properties, including tunable electrical property, optical and high mechanical properties, easy synthesis and effortless fabrication and high environmental stability over conventional inorganic materials.

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