High Modulus and High Tg Thermally Stable Polymers from Di-p-ethynylbenzoyl Ester Monomers: Synthesis, Solid State Polymerization; Processing, and Thermal Properties

1994 ◽  
Vol 27 (10) ◽  
pp. 2675-2684 ◽  
Author(s):  
Anastasios P. Melissaris ◽  
Morton H. Litt
Keyword(s):  
Thermal Properties ◽  
Solid State ◽  
Thermally Stable ◽  
High Modulus ◽  
Thermally Stable Polymers ◽  
Solid State Polymerization

scholarly journals Solid-State Polymerization of Poly(Ethylene Furanoate) Biobased Polyester, III: Extended Study on Effect of Catalyst Type on Molecular Weight Increase

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 438 ◽  
Author(s):  
Yosra Chebbi ◽  
Nejib Kasmi ◽  
Mustapha Majdoub ◽  
George Papageorgiou ◽  
Dimitris Achilias ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Solid State ◽  
Intrinsic Viscosity ◽  
Weight Increase ◽  
Degree Of Crystallinity ◽  
Solid State Polymerization ◽  
End Groups ◽  
Poly Ethylene ◽  
Molecular Weight Increase

In this study, the synthesis of poly(ethylene furanoate) (PEF), catalyzed by five different catalysts—antimony acetate (III) (Sb Ac), zirconium (IV) isopropoxide isopropanal (Zr Is Ip), antimony (III) oxide (Sb Ox), zirconium (IV) 2,4-pentanedionate (Zr Pe) and germanium (IV) oxide (Ge Ox)—via an industrially common combination of melt polymerization and subsequent solid-state polymerization (SSP) is presented. In all reactions, proper amounts of 2,5-dimethylfuran-dicarboxylate (DMFD) and ethylene glycol (EG) in a molar ratio of DMFD/EG= 1/2 and 400 ppm of catalyst were used. Polyester samples were subjected to SSP procedure, under vacuum application, at different reaction times (1, 2, 3.5, and 5 h) and temperatures of 190, 200, and 205 °C. Carboxyl end-groups concentration (–COOH), intrinsic viscosity (IV), and thermal properties, via differential scanning calorimetry (DSC), were measured for all resultant polymers to study the effect of the used catalysts on the molecular weight increase of PEF during SSP process. As was expected, it was found that with increasing the SSP time and temperature, the intrinsic viscosity and the average molecular weight of PEF steadily increased. In contrast, the number of carboxyl end-groups content showed the opposite trend as intrinsic viscosity, that is, gradually decreasing during SSP time and temperature increase. It is worthy to note that thanks to the SSP process an obvious and continuous enhancement in the thermal properties of the prepared PEF samples was attained, in which their melting temperatures (Tm) and degree of crystallinity (Xc) increase progressively with increasing of reaction time and temperature. To predict the time evolution of polymers IV, as well as the hydroxyl and carboxyl content of PEF polyesters during the SSP, a simple kinetic model was developed. From both the theoretical simulation results and the experimental measurements, it was demonstrated that surely the Zr Is Ip catalyst shows the best catalytic characteristics compared to all other used catalysts herein, that is, leading in reducing—in a spectacular way—the activation energy of the involved both transesterification and esterification reactions during SSP.

High Modulus and High Tg Thermally Stable Polymers from p-Ethynyl-Terminated Monomers. 3

1995 ◽  
Vol 28 (4) ◽  
pp. 860-865 ◽  
Author(s):  
Anastasios P. Melissaris ◽  
James K. Sutter ◽  
Morton H. Litt ◽  
Daniel P. Scheiman ◽  
Marla A. Schuerman
Keyword(s):  
Thermally Stable ◽  
High Modulus ◽  
Thermally Stable Polymers

scholarly journals Thermal properties of α,ա- aminoalkylterephthalamides prepared from waste poly(ethyleneterephthalate) bottle and aliphatic diamines

2017 ◽  
Vol 1 (T4) ◽  
pp. 36-47
Author(s):  
Cuong Ngoc Hoang ◽  
Yen Hoang Dang
Keyword(s):  
Thermal Properties ◽  
Solid State ◽  
Chemical Reaction ◽  
Melting Process ◽  
Melting Points ◽  
Hexamethylene Diamine ◽  
Solid State Polymerization ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Aliphatic Diamines

Trimers and pentamers of α,ա- aminoalkylterephthalamides were prepared from aminolysis of waste poly(ethyleneterephthalate) (PET) bottle with tetramethylene diamine (TMDA) and hexamethylene diamine (HMDA). The thermal properties of these products determined by DSC and TG showed that the melting points were the temperatures at which physical melting process and chemical transamidation polymerization occured concurrently. This chemical reaction had converted trimers and pentamers into polymers, then at the higher temperature ranges, the observed decomposition temperatures were just specific for newly formed polyamides, not for initial trimers or pentamers. The application of thermogravimetric chamber as mini reactor is quite useful to investigate the heating conditions for solid-state polymerization of α,ա- aminoalkylterephthalamides.

Highly thermally stable Cr3+ and Yb3+ codoped Gd2GaSbO7 phosphors for broadband near-infrared applications

2021 ◽  
Author(s):  
xiudi wu ◽  
shuang zhao ◽  
Liang Zhang ◽  
Langping Dong ◽  
Yonghui Xu ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Emission Band ◽  
Near Infrared ◽  
Thermally Stable ◽  
Nir Emission

Abstract：Gd2GaSbO7:Cr3+,Yb3+ phosphors with efficient broadband NIR emission were prepared by solid-state reaction. Under the excitation of 448 nm, Gd2GaSbO7:Cr3+ (GGS:Cr3+) phosphor exhibits a broadband NIR emission band centered at approximately...

A novel thermally stable Ba3Bi2(BO3)4:Eu3+ red phosphor for solid state lighting application

2019 ◽  
Vol 216 ◽  
pp. 116714 ◽  
Author(s):  
A.P. Shablinskii ◽  
I.E. Kolesnikov ◽  
R.S. Bubnova ◽  
A.V. Povolotskiy ◽  
E. Lähderanta ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Lighting ◽  
Thermally Stable ◽  
Red Phosphor ◽  
Lighting Application
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