Diffusion and morphological properties of sydiotactic polypropylene (sPP) films
Journal
Polymer Engineering and Science
Journal Volume
49
Journal Issue
4
Pages
740-746
Date Issued
2009
Author(s)
Abstract
Abstract Four different fabrication procedures were used for casting thin films of syndiotactic polypropylene (sPP). A hot press system operated at 200°C and 30 MPa pressure was used to melt polypropylene powder and make the cast films. Different cooling procedures were used to anneal the films, including cooling in liquid nitrogen (LN), ice water, and air at room temperature (RT). The morphological and mass transfer properties of the films were studied with XRD, polarized optical microscopy, bulk flow, and diffusion experiments. All sPP films contained amorphous and crystalline phases. The crystalline phase was determined to be disordered Form I. The sPP films annealed with LN had the lowest crystallinity whereas the sPP films cooled in air at RT had the highest crystallinity. Diffusion of toluene in the films and comparison with Maxwell's equation indicated that the crystalline phase mass permeability is much lower than the amorphous phase, which causes films with low crystallinity to have a higher effective diffusion constant and permeability compared with high crystallinity films. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
SDGs
Type
journal article