Polymers Subcommittee Agenda and Minutes
March 22, 2006
Chairman: Thomas Blanton
The Polymer Subcommittee has not met in several years. Therefore, there were no previous minutes to approve.
In 2000, the Polymer Subcommittee was established to pursue the idea of a PDF-3 polymer database. PDF-4+ 2005 has 895 polymer hits. Diffractometer data from 9 samples were collected from polymers and submitted to ICDD. John Faber created a database to evaluate data.
It should be pretty easy to get digitized data from external publications. We can probably buy software that can digitize data from journals. We would look for 1D data and 2D data.
The following list of significant polymers was put together several years ago, but has not been updated since the last meeting of this subcommittee. (See PDF - Polymers)
A practical example would be material deposited on filter paper. A PDF-3 polymer database would help identify the diffraction pattern due to the filter paper.
In an attempt to determine the direction this subcommittee should take, many questions were asked:
Where do we go? Is such a product in demand? Should we pursue a polymer database or some type of PDF-3 database? Should it be pursued in terms of a Jane Turley type book on computer with the image available? Or should it be taken a step further to whole pattern fitting? Should a polymer product be a plug-in to the PDF and not a separate database? Would it be useful for some polymers to be in their common oriented state?
While it was determined that whole pattern fitting would most likely not be useful, a list of constructive features was gathered.
- Generate a pattern to view would be useful.
- Random and oriented patterns
- Commercially available items – June Turley's patterns were from unoriented samples. Useful patterns would be oriented Teflon and Saran wrap.
- Note how the sample was made so that it is obvious to the user. This is needed to make the database useful.
- Molecular weight effect
An ICDD Polymer Subcommittee meeting will be held at the 2007 Denver X-ray Conference in conjunction with Randy Barton's Polymer Session which normally attracts 40-60 attendees. The ICDD should plan to participate in and/or organize a workshop. Samples of polymer patterns should be available and will require some involvement from Headquarters.
The need for this Subcommittee will be reevaluated after this 2007 meeting.
The minutes from the March 2001 meeting were approved.
There are ~1,000 data files available in the sample database and there have been some commitments from others to submit data.
Action item: J. Faber and S. Murthy will review June Turley's book and decide whether to scan the data in the book to generate electronic database or to collect new data from scratch.
Action item: T. Blanton and S. Murthy will design the framework for acceptance of the data.
The Polymers Subcommittee would like to enable the scattering/diffraction community to make the best use of their X-ray diffraction data in analyzing polymeric materials. It should be kept in mind however, that the type of data that polymer people deal with, and their needs are different from those who work with minerals, metals/alloys, ceramics, pharmaceuticals, organics, etc.
The goals of this subcommittee are to make polymer diffraction results more accessible in a manner similar to IR, DSC, and XRF, and less threatening than it is today (crystallinity on the fly, identification when possible, a central resource for nuts and bolt of analysis) and to cover all aspects of polymer diffraction, including 1-D powder and 2-D polymer data.
To reach these goals we need to archive powder type polymer data (extend the utility of the excellent work done by June Turley by digitizing the data, updating the data and adding new data). We also need to make the polymer data searchable and to archive 2-D polymer data.
Progress has been made as several people have submitted several data files. J. Faber has constructed an operational database that can be distributed to the members on a CD-ROM. And, as previously state, several people have committed to help populate the database.
- J. Faber demonstrated the work that has been done thus far. The first step was to get the data (12 patterns) into a database. The following are issues that were discussed:
- The structure of the database.
- What data would be most useful for a product? Keep in mind there are two sets of users, the polymer analyst and the general analyst and the two may have very different needs.
- The Dow Polymer Book may provide a good basis and is the only database the polymer community has.
- J. Kaduk questioned how much of the variability issue can be calculated on-the-fly.
- T. Blanton suggested that the first step is to help people with phase identification; the 2-D gets more complex when dealing with coatings on films, etc.
- Radiation shouldn't matter; the database should be able to handle the conversion.
- Needs to be user-friendly - archival, presentation and ability to manipulate the data.
- The ICDD would like the 2-D patterns in graphics format.
The following are activities for the future:
· Facilitate standardizing the methods of analysis - promote best practices for data analysis.
· Polymer laboratory courses at the ICDD to compliment the polymer workshop.
· Run round robins to standardize polymer data collection and analysis.
· SAXA data?
· Educate the diffraction community, polymer community and the instrument manufacturers.
Meeting was adjourned.