反应详情

The following examples show that conjugated diene units can also be incorporated in butyl elastomers by carbocationic copolymerization with isobutylene. Technical grade (80%) alloocimene, (2,6-dimethyl-2,4,6-octatriene) of 95.6% actual purity level which was purchased from Aldrich and dried by column chromatography using aluminum oxide (neutral, Brockmann I activity (Aldrich) and degassed by freeze-pump-thaw technique. Isobutylene (IB), 99% purity and methyl chloride (MeCl), 99.5% purity (Matheson TRIGAS) were condensed from gas phase after drying it by passing through a column filled with BaO/CaCl2. Hexane(s) (Mallinckrodt Chemicals with 98.5% minimum purity) was freshly distilled off CaH2 (Aldrich). Di-tert-butylpyridine (DtBP, 97%, TIC), N,N-Dimethyl acetamide (DMA, 99.8%, anhydrous, Aldrich) and titanium tetrachloride (TiCl4, 99.9%, Aldrich) were used as received. p-Vinylcumyl methyl ether (inimer) was synthesized based on the procedure described in (C. Paulo, J. E. Puskas, Macromolecules 2001, 34, 734-739). It was purified by column chromatography using neutral Brockmann activity I alumina (Aldrich) and n-pentane. 2-Chloro-2,4,4-trimethylpentane (TMPCl) was made by hydrochlorination of 2,4,4-trimethylpent-1-ene (TMP-1, Acros). After completion of the reaction, solution was neutralized by the slow addition of sodium bicarbonate, dried over CaH2 and filtered. It was degassed with freeze-pump-thaw cycles.

1. customdried by column chromatography
2. customdegassed by freeze-pump-thaw technique
3. customcondensed from gas phase
4. customafter drying it
5. additionfilled with BaO/CaCl2
6. distillationHexane(s) (Mallinckrodt Chemicals with 98.5% minimum purity) was freshly distilled off CaH2 (Aldrich)
7. customIt was purified by column chromatography
8. customAfter completion of the reaction, solution
9. customdried over CaH2
10. filtrationfiltered
11. customIt was degassed with freeze-pump-thaw cycles