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| Content Provider | Springer Nature Link |
|---|---|
| Author | Yalcin, Talat Schriemer, David C. Li, Liang |
| Copyright Year | 1997 |
| Abstract | An analytical method based on matrix-assisted laser desorption ionization (MALDI) time-of-flight mass spectrometry has been developed to provide information on oligomer structure, average molecular weight, and molecular weight distributions of polydienes (e.g., polybutadiene and polyisoprene), an important class of industrial polymers. This MALDI method involves the use of all-trans-retinoic acid as the matrix, copper (II) nitrate as the cationization reagent, and tetrahydrofuran as the solvent. The incorporation of this copper salt generates Cu$^{+}$ adducts with the polymer chains. It also improves the signal strength and extends the upper mass range when used with all-trans-retinoic acid, as compared to silver nitrate. With this formulation, it is demonstrated that polybutadienes of narrow polydispersity with masses up to 300,000 u and polyisoprenes of narrow polydispersity with masses up to 150,000 u can be analyzed. The upper molecular weight limit is set by the requirement of using higher matrix-to-polymer ratios with increasing polymer molecular weight, to the point where the instrument can no longer detect the small quantity of polymer present in the matrix host. It is also shown that this sample preparation generates previously unreported adduction behavior. The practical implications of this adduction behavior on polymer structural analysis, accuracy of molecular weight determination, and the upper molecular weight limit of oligomer resolution are discussed. It is illustrated that, in a linear time-lag focusing MALDI instrument, oligomer resolution can be obtained for polydienes with molecular weights up to 24,000, providing structural confirmation of the end-groups and the repeat unit. The average molecular weights of a number of polydienes of narrow polydispersity determined by MALDI are compared to those obtained by gel permeation chromatography, and discrepancies are noted. |
| Starting Page | 1220 |
| Ending Page | 1229 |
| Page Count | 10 |
| File Format | |
| ISSN | 10440305 |
| Journal | Journal of The American Society for Mass Spectrometry |
| Volume Number | 8 |
| Issue Number | 12 |
| e-ISSN | 18791123 |
| Language | English |
| Publisher | Springer-Verlag |
| Publisher Date | 1997-01-01 |
| Publisher Institution | The American Society for Mass Spectrometry |
| Publisher Place | New York |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Analytical Chemistry Biotechnology Organic Chemistry Proteomics Bioinformatics |
| Content Type | Text |
| Resource Type | Article |
| Subject | Spectroscopy Structural Biology |
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