Positron Annihilation Studies of the Free Volumes in Nylon12/PVA Films Treated by Supercritical Carbon Dioxide

Jingjing Li, Chongshan Yin, Yawei Zhou, Gang Li, Jen-taut Yeh, Chunqing He
2017 Acta Physica Polonica. A  
Free volume variations of Nylon12/Polyvinyl alcohol (Nylon12/PVA) blends treated in supercritical carbon dioxide (ScCO2) were investigated using positron annihilation lifetime spectroscopy. It is found that o-Ps lifetime τ3 and the corresponding intensity I3 in Nylon12/PVA decrease with increase of the PVA content. Being treated in ScCO2 at 50 • C and 20 MPa for 1 h, the free volume holes in Nylon12/PVA blends expand to different extents depending on the weight ratio of PVA. After releasing of
more » ... O2, the free volume size decreases as a function of the elapsed time due to the molecular relaxation, and the relaxation time constant depends on the content of PVA in the blends.
doi:10.12693/aphyspola.132.1552 fatcat:lzuj6kcxgrbzlh2ianorzrkjpe