scholarly journals Conformation of high-molecular-weight poly(L-valine) in solid state.

1975 ◽  
Vol 72 (3) ◽  
pp. 941-942 ◽  
Author(s):  
S. Yamashita ◽  
T. Yamashita
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
High Molecular Weight ◽  
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.

A solid-state synthesis, mechanism, and characterization of high molecular weight poly (3-aminobenzenesulfonic acid) with FeCl3.6H2O as a binary oxidant and dopant

2019 ◽  
Vol 26 (1) ◽  
Author(s):  
Ali Reza Modarresi-Alam ◽  
Vahid Zeraatkar ◽  
Fateme Alsadat Tabatabaei ◽  
Mojdeh Bazrafkan ◽  
Amirhosein Salmani Dastgerdi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
High Molecular Weight ◽  
Solid State Synthesis ◽  
Synthesis Mechanism ◽  
High Molecular Weight Poly

Autoxidative Degradation of Poly(phenylacetylene)

1993 ◽  
Vol 58 (11) ◽  
pp. 2651-2662 ◽  
Author(s):  
Jiří Vohlídal ◽  
Dana Rédrová ◽  
Marta Pacovská ◽  
Jan Sedláček
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Induction Period ◽  
High Molecular Weight ◽  
Size Exclusion Chromatography ◽  
Main Chain ◽  
Size Exclusion ◽  
Cross Linking ◽  
Exclusion Chromatography ◽  
High Molecular Weight Poly

Autooxidative degradation of high molecular-weight poly(phenylacetylene) (PPhA) in solid state and in solution was studied using the size exclusion chromatography (SEC) and UV, IR, and EPR spectrometry. No degradation was observed on PPhA stored in vacuum, whereas the polymer exposed to air was found to degrade without any induction period. No evidence of a cross-linking of oxidized PPhA was observed. The degradation of PPhA was found to be: (i) practically non-influenced by an ambient, diffuse day-light; (ii) of the random type (i.e. each main-chain bond of PPhA has the same probability of being ruptured); and (iii) fast enough to influence the results of SEC measurements.

Linear and high-molecular-weight poly-porphyrins for efficient photodynamic therapy

2021 ◽  
Author(s):  
Nan Zheng ◽  
Xiahui Li ◽  
Shangwei Huangfu ◽  
Kangkai Xia ◽  
Ruofei Yue ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Singlet Oxygen ◽  
High Molecular Weight ◽  
Linear Poly ◽  
High Molecular Weight Poly

A linear poly-porphyrin with high Mw and conjugated by PEG and acetazolamide was developed with enhanced singlet oxygen quantum yield, improved photo-toxicity and excellent in vivo photodynamic therapy.

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