High molecular weight poly (L -lactic acid) clay nanocomposites via solid-state polymerization

2011 ◽  
Vol 32 (3) ◽  
pp. 497-509 ◽  
Author(s):  
Vimal Katiyar ◽  
Hemant Nanavati
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Solid State ◽  
High Molecular Weight ◽  
Clay Nanocomposites ◽  
Solid State Polymerization ◽  
High Molecular Weight Poly

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.

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