Targeted Materials
Polymers
(PDF-2 Release 2018, PDF-4+ 2018, PDF-4/Organics 2018)


ICDD® Powder Diffraction File™ (PDF®) XRD patterns for poly(ethylene glycol), PEG.
PDF 00-067-1545 PEG 600 Mn (A) raw data PD3 XRD pattern  (C) simulated 2D XRD pattern (20Å crystallite size) and PDF 00-067-1538 PEG 7500 Mn (B) raw data PD3 XRD pattern  (D) simulated 2D XRD pattern (400Å crystallite size)

 

New Capabilities: Crystallinity and crystallite size measurements
Polymers often can pose a challenge for XRPD investigations. Variations in macromolecule chain length, the occurrence of chain branching, and processing conditions often results in polymer materials that can be amorphous, semi-crystalline, highly crystalline, randomly oriented, or preferentially oriented. In commercial applications, many composites are comprised of a polymer base with inorganic or organic additives present. Inclusion of raw data XRPD patterns for polymers in the PDF database, starting in Release 2009, provides a more complete picture to help identify crystalline and amorphous components of a polymer XRPD pattern. The original discussion of including full pattern polymer data in the PDF began with an International Centre for Diffraction Data (ICDD) task group member. It is now a reality with 174 polymer raw data XRPD patterns in the PDF, focusing on high volume commercial polymers. This includes 10 new patterns added to the 2018 product line release.

Having PD3 raw data patterns in the PDF is beneficial for phase identification and materials characterization, particularly for matrix or composite samples. In pharmaceuticals, polymer are often the major component of a medication and the polymers are typically amorphous or nanocrystalline.

Characterization of Clopidogrel 75mg using XRD and phase identification using the ICDD PDF. Four polymeric species are identified: methyl cellulose, crospovidone, hydroxylpropyl cellulose, and polyethylene glycol.

 

New Polymers added to the 2018 Product Line

This includes 57 new patterns added to the 2018 product line release.


Technical Presentations on Polymers

Tutorial

How to analyze polymers using X-ray diffraction

ICDD Workshop EPDIC 14

"X-ray Diffraction Analysis of Polymers – Expanding Materials Characterization Capabilities" – T. N. Blanton, ICDD, Newtown Square, PA

Presentation PPXRD-13

"ICDD Powder Diffraction File coverage of polymers used in pharmaceutical and biomedical applications" – T. N. Blanton, S. Gates

Publications

"Reference materials for the study of polymorphism and crystallinity in cellulosics" - T. G. Fawcett, C. E. Crowder, S. N. Kabekkodu, F. Needham, J. A. Kaduk, T. N. Blanton, V. Petkov, E. Bucher and R. Shpanchenko

"A new “chain” of events: polymers in the Powder Diffraction File™ (PDF®)" - S. D. Gates, T. N. Blanton, and T. G. Fawcett

"Characterization of Nafion proton exchange membrane films using wide-angle X-ray diffraction" – T. N. Blanton, R. Koestner