Study on the monomer reactivity ratio and performance of EPEG-AA (ethylene-glycol monovinyl polyethylene glycol–acrylic acid) copolymerization system

In this work, the thermal decomposition of copolymers based on polyethylene glycol fumarate with the acrylic acid using various ratios of initial monomers has been studied for the first time. The samples were studied in air and nitrogen. According to the thermograms analysis, it was found that the copolymer sample decomposition begins at higher temperatures for a copolymer with high content of polyester resin. The copolymer is vigorously oxidized by the oxygen when heated in air, and one can observe almost complete sample decomposition, whereas it decomposes with a residue of ~ 15% in an inert medium. The activation energies for copolymers with different compositions were estimated using the differential methods of Freeman-Carroll, Achar and Sharpe-Wentworth. The activation energy values found by the three methods demonstrated a good convergence. It was shown that, the activation energy values are higher (~ 200 kJ/mol in the inert medium, and ~ 95 kJ/mol in the oxygen atmosphere) for a copolymer with a lower composition of polyester resin, and the activation energy is ~180 and ~85 kJ/mol for a copolymer with a greater composition of p-EGF-AA. The copolymer is more thermostable in the nitrogen atmosphere according to the kinetic parameters. Additionally, there were determined the thermodynamic characteristics, such as the Gibbs energy (∆G) and the entropy (∆S). They also confirm the destruction process dependence on the components ratio in the synthesized copolymer.

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Synthesis and Performance Evaluation of Linear Polycarboxylate Dispersant of Glacial Acrylic Acid – Maleic Acid- Sodium Methallyl Disulfonate for Ceramics

Journal of the Korean Ceramic Society ◽

10.4191/kcers.2018.55.2.06 ◽

2018 ◽

Vol 55 (2) ◽

pp. 126-134 ◽

Cited By ~ 1

Author(s):

Kiran Kumar Kommanapalli ◽

Pierre Lyot ◽

Jhansi Rani Sunkara ◽

Pierrick Checule

Keyword(s):

Performance Evaluation ◽

Acrylic Acid ◽

Maleic Acid ◽

And Performance

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Study of the properties of Ce3+-doped fluoride nanophosphors: phase composition, morphology, luminescence

Journal of Physics Conference Series ◽

10.1088/1742-6596/2056/1/012048 ◽

2021 ◽

Vol 2056 (1) ◽

pp. 012048

Author(s):

A M Dorokhina ◽

V V Bakhmetyev ◽

H Kominami ◽

A Toru ◽

M Hisashi

Keyword(s):

Particle Size ◽

Photodynamic Therapy ◽

Phase Composition ◽

Polyethylene Glycol ◽

Ethylene Glycol ◽

Solvothermal Synthesis ◽

Luminescent Properties ◽

Optimal Duration ◽

Oncological Diseases ◽

Synthesis Medium

Abstract To date, nanophosphors have found application in various fields, one of which is medicine. These phosphors were developed with the aim to become one of the components of a drug for photodynamic therapy of oncological diseases. The aim of this work was to study the effect of the duration, environment, and stabilizers of solvothermal synthesis on the microstructure and luminescent properties of the YF3:Ce nanophosphor. The solvothermal synthesis technique was carried out in three different media: water, ethanol, and ethylene glycol. The optimal duration of the synthesis was also determined (the synthesis was carried out at a temperature of 200°C for 4…20 hours). The dependence of the YF3 luminescence on the phase composition and the solvothermal synthesis medium was studied. Using SEM, the morphology and particle size of YF3:Ce phosphors were studied depending on different stabilizers (polyethylene glycol, polyethyleneimine, polyvinylpyrrolidone). The luminescence intensity of YF3:Ce and Na(Y1,5Na0,5)F6:Ce samples was compared.

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