Mass spectroscopy and SEC of SRM 1487, a low molecular weight poly(methyl methacrylate) standard
✍ Scribed by Charles M. Guttman; William R. Blair; Paul O. Danis
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 275 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0887-6266
No coin nor oath required. For personal study only.
✦ Synopsis
Matrix Assisted Laser Desorption Ionization (MALDI) Time of Flight (TOF) Mass Spectrometry (MS) was used to study the molecular weight distribution (MWD) and the number of a-methyl styrene (a-MeSty) repeat units in SRM 1487, a narrow MWD poly(methyl methacrylate) (PMMA) standard reference material of about 6300 g/mol, which was initiated with a-MeSty. It was found that each PMMA polymer chain had from zero to seven a-MeStys per chain. The MWD of the polymer chains containing a fixed number of a-MeStys was obtained. The MWD, M w , and the average number of a-MeSty at a given molecular weight from MALDI TOF MS compare well with those obtained from more traditional methods such as ultracentrifugation and Size Exclusion Chromatography (SEC). The implications of the number of a-MeStys per chain is discussed in terms of the chemistry of anionic polymerization.