Abstract
AbstractThe anisotropic structures found in drawn poly(lactic acid) films are strongly correlated to their overall dimensional stability. Several aspects of this relationship can be efficiently characterized by Raman spectroscopy. We determined the degree of orientation in these drawn films by measuring the relative intensity of the polarized and depolarized components and the shift in the relative band positions. The bandwidth and specific band frequency also correlated well with the degree of sample crystallinity. These aspects make the Raman method amenable for the online monitoring of orientation and crystallinity in commercial processes. A molecular understanding of heat setting to reduce film shrinkage is also proposed. Raman data from films that were heat‐set while physically constrained suggest that amorphous‐phase relaxation does not occur during heat setting. Rather, the level of crystallinity increases substantially, indicating that the cause of low shrinkage in the films was due to crystalline network formation rather than amorphous‐phase relaxation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2497–2505, 2001
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
