Polymer-supported reagents as aids in controlled degradation of polymers containing ozonides in the main chain to give telechelic oligomers
✍ Scribed by Stephen Rimmer; John R. Ebdon; Melanie J. Shepherd
- Book ID
- 103997768
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 810 KB
- Volume
- 26
- Category
- Article
- ISSN
- 1381-5148
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✦ Synopsis
The work-up of ozonides derived from the ozonolysis of methacrylate copolymers containing main chain unsaturation has been studied. We have used: periodate supported on Amberlyst A26 (SPIR) (a supported oxidizing agent); polystyrene-supported diphenyl phosphine (SPR) ( a mild supported reducing agent) and borohydride supported on Amberlyst A26 (BER) (a more powerful supported reducing agent). Poly(buty1 methacrylate-cobutadiene)s were synthesized by starve fed emulsion polymerization. These materials, and the homopolymer, poly(buty1 methacrylate), were then ozonized at different temperatures and worked up with each of the reagents listed above. The differing work-ups generated telechelic oligomers in good yield (99%+). Changes in molecular weight with ozonization temperature were observed. Aldehyde end-groups were detected by 'H-and 13C-NMR. Hydroxyl end-groups were observed by FTIR and 13C-NMR spectroscopy. The presence of hydroxyl groups was also further confirmed by forming the tosylate. Carboxyl groups were observed by FTIR and 13C-NMR and quantified by titration. SPR-generated oligomers had approximately 80% of the chain-ends aldehyde functional, BER and SPIR gave oligomers with 99+% hydroxyl and carboxyl functionality, respectively.