Bubble Growth in Poly(methyl methacrylate) and Carbon Dioxide Mixture

Polymers

Xiaofei Xu¹  Jie Chu¹ 

[1] Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China;

关键词: poly(methyl methacrylate);    carbon dioxide;    mixture;    bubble nucleation;    molecular dynamics simulation;    free volume;   

DOI  :  10.3390/polym11040648

来源: DOAJ

【 摘 要 】

In this paper, we study bubble nucleation and growth in a poly(methyl methacrylate) and CO ${}_2$ mixture by molecular dynamics simulations. It is known in the foaming industry that the bubble size has a more uniform distribution with a higher start-up pressure. The real physical reason remains unclear. In this work, we found that the free volume-rich polymer segments could adsorb many small-size bubbles in the region close to the polymer chain. The existence of these small bubbles limits the number of free CO ${}_2$ molecules, which is helpful for bubble stabilization. Moreover, the free volume of polymer segments decreases with an increase of the start-up pressure. As a result, the size of the large bubbles becomes more uniform with a higher startup pressure.

【 授权许可】

Unknown