Cavity size distributions in high free volume glassy polymers by molecular simulation

Autor:	Ying Lu, Xiao-Yan Wang, Matthew T. Stone, Benny D. Freeman, Isaac C. Sanchez, Kenneth M. Lee
Rok vydání:	2004
Předmět:	chemistry.chemical_classification Cavity size Polymers and Plastics Organic Chemistry Monte Carlo method Thermodynamics Polymer chemistry.chemical_compound Molecular dynamics chemistry Volume (thermodynamics) Polymer chemistry Materials Chemistry Copolymer Tetrafluoroethylene Spectroscopy
Zdroj:	Polymer. 45:3907-3912
ISSN:	0032-3861
DOI:	10.1016/j.polymer.2004.01.080
Popis:	Two very permeable polymers, poly(1-trimethylsilyl-1-propyne) (PTMSP) and a random copolymer of tetrafluoroethylene and 2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxole (TFE/BDD), have very similar and large fractional free volumes (FFV), but very different permeabilities. Using atomistic models, cavity size (free volume) distributions determined by a combination of molecular dynamic and Monte Carlo methods are consistent with the observation that PTMSP is more permeable than TFE/BDD. The average spherical cavity size in PTMSP is 11.2 A whereas it is only 8.2 A in TFE/BDD. These cavity size distributions determined by simulation are also consistent with free volume distributions determined by positron annihilation lifetime spectroscopy.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ddddbe69d9e2a4b4356896bc14374653 https://doi.org/10.1016/j.polymer.2004.01.080 Zobrazit plný text záznamu Full Text from ScienceDirect