Solid state polymerization of poly(L-lactide): Multiple-fold increase in molecular weight via an efficient catalyst system

2011 ◽  
Vol 51 (10) ◽  
pp. 2078-2084 ◽  
Author(s):  
Vimal Katiyar ◽  
Hemant Nanavati
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Fold Increase ◽  
Catalyst System ◽  
Efficient Catalyst ◽  
Solid State Polymerization

Broadening of molecular-weight distribution in solid-state polymerization resulting from condensate diffusion

2000 ◽  
Vol 79 (5) ◽  
pp. 928-943 ◽  
Author(s):  
Michael D. Goodner ◽  
Stephen M. Gross ◽  
Joseph M. Desimone ◽  
George W. Roberts ◽  
Douglas J. Kiserow
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
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.

Preparation and characterization of high molecular weight poly(trimethylene terephthalate) by solid-state polymerization

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Kim Seok Hoon ◽  
Kim Joon Ho
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
Solid State ◽  
High Molecular Weight ◽  
Melting Temperature ◽  
Average Molecular Weight ◽  
Pellet Size ◽  
Solid State Polymerization ◽  
Trimethylene Terephthalate ◽  
High Molecular Weight Poly

AbstractSolid-state polymerization has been widely used to prepare high molecular weight poly(ethylene terephthalate). Solid-state polymerization is generally carried out by heating solid, melt-phase-polymerized polymer below its melting temperature but above its glass transition temperature. Solid-state polymerization of poly(trimethylene terephthalate)(PTT) is not an independent process but rather an additional process with respect to melt polymerization that is used when PTT of a higher molecular weight is required. Two kinds of commercial PTT chips were polymerized in the solid state to prepare high molecular weight PTT, which were characterized by end group contents, molecular weight, thermal analysis and X-ray diffraction. In the solid-state polymerization of PTT, the overall reaction rate was governed by the reaction temperature, reaction time and pellet size. The content of carboxyl end groups was decreased during the solid-state polymerization with increasing reaction time and temperature. The melting temperature and crystallinity of solid-state-polymerized PTT were higher at longer times and higher temperatures of polymerization. The activation energy for the solid-state polymerization of PTT was in the range of 24~25 kcal/mol for each chip. Through the solid-state polymerization of commercial PTT chips, we could get high molecular weight polymers up to an intrinsic viscosity value of 1.63 dl/g, which is equivalent to about a 117,000 weight-average molecular weight.

High molecular weight bio furan-based co-polyesters for food packaging applications: synthesis, characterization and solid-state polymerization

2016 ◽  
Vol 18 (19) ◽  
pp. 5142-5150 ◽  
Author(s):  
Sungmin Hong ◽  
Kyung-Deok Min ◽  
Byeong-Uk Nam ◽  
O Ok Park
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
High Molecular Weight ◽  
Food Packaging ◽  
Melt Polycondensation ◽  
Solid State Polymerization

High molecular weight bio furan-based copolyesters have been synthesized by melt polycondensation and solid-state polymerization for packaging applications as bio based alternatives to PET.

Solid-state polymerization of poly(aryl carbonates): a facile route to high-molecular-weight polycarbonates

1993 ◽  
Vol 26 (5) ◽  
pp. 1186-1187 ◽  
Author(s):  
V. S. Iyer ◽  
J. C. Sehra ◽  
K. Ravindranath ◽  
S. Sivaram
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
High Molecular Weight ◽  
Solid State Polymerization ◽  
Facile Route

scholarly journals New Aspects on the Direct Solid State Polycondensation (DSSP) of Aliphatic Nylon Salts: The Case of Hexamethylene Diammonium Dodecanoate

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2625
Author(s):  
Angeliki D. Mytara ◽  
Athanasios D. Porfyris ◽  
Stamatina N. Vouyiouka ◽  
Constantine D. Papaspyrides
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Critical Parameter ◽  
Critical Parameters ◽  
Reaction Conditions ◽  
Solid State Polymerization ◽  
Salt Crystals ◽  
Direct Solid ◽  
End Group ◽  
Aliphatic Polyamide

The direct solid state polymerization (DSSP) of hexamethylene diammonium dodecanoate (PA 612 salt) was investigated for two different salt grades, fossil-based and bio-based. Aliphatic polyamide salts (such as PA 612 salt) are highly susceptible to solid melt transition (SMT) phenomena, which restrain the industrial application of DSSP. To that end, emphasis was given on reactor design, being the critical parameter influencing byproduct diffusion, amine loss and inherent DSSP kinetics. Experiments took place both at the microscale and the laboratory scale, in which two different reactors were tested in terms of bypassing SMT phenomena. The new reactor designed here proved quite successful in maintaining the solid state during the reaction. Scouting experiments were conducted in order to assess the effect of critical parameters and determine appropriate reaction conditions. Fossil-based PA 612 products proved to have a better end-group imbalance in comparison to bio-based ones, which is critical in terms of achieving high molecular weight. Finally, a real DSSP process was demonstrated, starting from PA 612 salt crystals and ending with PA 612 particles.

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