Abstract
A pair of attenuated total reflection infrared (ATR IR) spectra obtained during the crystallization of bioplastic copolymer poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] or PHBHx from the melt by spontaneous cooling were examined using the two-trace two-dimensional correlation spectroscopy (2T2D-COS) analysis. Unlike conventional difference spectra, 2T2D spectra showed unexpected details for the patterns of spectral intensity changes, clearly revealing the existence of two distinct populations of crystalline contributions, attributed to the well-ordered primary crystals and the less ordered secondary crystals, in addition to the amorphous component. The 2T2D spectrum sorts out highly overlapped bands associated with different constituents of the system, based on the fundamental properties and constraint imposed on a pair of spectra. Hetero-mode asynchronous 2T2D correlation analysis between the congested CH–stretching region and better resolved carbonyl-stretching region further indicates that the increase in the intensities of certain methyl and methylene bands during the crystallization process is mostly associated with the growth of the well-ordered primary crystals of PHBHx instead of the formation of the secondary crystals in the confined inter-lamellar space.
© 2021 The Author(s)
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription
Add to BibSonomy