High resolution electron microscopy of bis-(-2-hydroxyethyl)terephthalate crystalline polymers

Area of Science:

• Materials Science
• Crystallography
• Polymer Science

Background:

• Bis-(2-hydroxyethyl)terephthalate (BHET) is a key intermediate in polyester production.
• Characterizing BHET crystal structure is crucial for understanding polymer properties.
• Previous studies lacked detailed crystallographic information on large BHET crystals.

Purpose of the Study:

• To report high-resolution transmission electron microscopy (HRTEM) studies of BHET crystals.
• To investigate the crystallography and polymorphism of BHET crystals.
• To correlate crystallographic data with electron microscopy and diffraction results.

Main Methods:

• Preparation of large BHET crystallites using a novel method.
• High-resolution transmission electron microscopy (HRTEM).
• X-ray diffractometry and infrared spectroscopy for crystallographic analysis.
• Electron diffraction for structural determination.

Main Results:

• Successful preparation of large BHET crystallites (centimeter scale).
• Detailed HRTEM micrographs revealing crystal morphology and structure.
• Identification of BHET polymorphism through X-ray diffractometry and infrared spectroscopy.
• Correlation between crystallographic data and electron microscopy/diffraction findings.

Conclusions:

• The novel preparation method yields large, well-characterized BHET crystals.
• HRTEM, X-ray diffraction, and infrared spectroscopy provide comprehensive insights into BHET crystallography.
• Understanding BHET crystal structure and polymorphism is essential for polyester synthesis and material properties.