Gas permeability through poly(4-methyl-1-pentene) at temperatures above and below the glass transition point


Citar

Texto integral

Acesso aberto Acesso aberto
Acesso é fechado Acesso está concedido
Acesso é fechado Somente assinantes

Resumo

Gas separation properties of polymer films based on semicrystalline poly(4-methyl-1-pentene) (PMP) with Tg = 30°C for permanent gases and some lower hydrocarbons have been experimentally studied in the temperature range of −20 to 80°C. Experiments have been performed using the differential permeability technique involving the determination of the diffusion coefficient by the characteristic time and functional scaling-up methods. It has been shown that PMP as a biphasic system may be characterized by one diffusion coefficient that includes the contributions of diffusion in the amorphous and crystalline phases. It has also been shown that despite the glass transition (phase transition) at 30°C, the permeability coefficients of the test gases exponentially increase with gas temperature and the temperature dependence curves do not exhibit an inflection in the glass transition region. On the other hand, the Arrhenius plots of the diffusion coefficients show a bend over the entire glass transition range in PMP, with the activation energy of diffusion decreasing with an increase in temperature. This fact demonstrates the unusual, earlier unknown effect of increasing activation energy of diffusion ED for gases below Tg.

Sobre autores

S. Markova

Topchiev Institute of Petrochemical Synthesis

Autor responsável pela correspondência
Email: markova@ips.ac.ru
Rússia, Moscow, 119991

N. Smirnova

Topchiev Institute of Petrochemical Synthesis

Email: markova@ips.ac.ru
Rússia, Moscow, 119991

V. Teplyakov

Topchiev Institute of Petrochemical Synthesis

Email: markova@ips.ac.ru
Rússia, Moscow, 119991

Arquivos suplementares

Arquivos suplementares
Ação
1. JATS XML

Declaração de direitos autorais © Pleiades Publishing, Ltd., 2016