Living coupling reaction in living cationic polymerization. 4. Synthesis of telechelic polyisobutylenes using bis-furanyl derivatives as coupling agents
S. Hadjikyriacou et al., Living coupling reaction in living cationic polymerization. 4. Synthesis of telechelic polyisobutylenes using bis-furanyl derivatives as coupling agents, J MACR S PU, 37(11), 2000, pp. 1333-1352
Citations number
21
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY
The synthesis of telechelic polyisobutylenes (PIB) by coupling with 2,5-bis
-(2-furyl-2-propyl)furan is described. Hydroxyl tele-chelic PIB with contro
lled molecular weight was obtained by haloboration-initiation of isobutylen
e (IB) with a BCl3/BBr3 mixture, followed by coupling of the living ends an
d oxidation of the (CH3O)(2)B- end groups with H2O2 in alkaline tetrahydrof
uran. Vinyl telechelic PIBs were prepared by coupling living PIB obtained u
sing a novel vinyl functional initiator 5-chloro-3,3,5-trimethyl-1-hexene i
n conjunction with TiCl4 in hexanes/CH3Cl (60/40, v/v) at -80 degreesC. Chl
orosilyl telechelic PIBs were synthesized for the first time by employing c
hlorosilyl Functional initiators (1-chloro-1-methyl)ethyl-3-(1-dichloro-met
hylsilyl-methyl)ethylbenzene and 1-methyldichlorosilyl-3,3,5-trimethyl-5-ch
loro-hexane in conjunction with TiCl4 in hexanes/CH3Cl (60/40, v/v) at -80
degreesC. After coupling, the dichlorosilyl groups were converted to dimeth
oxysilyl groups upon quenching with methanol. The bis-dimethoxysilyl telech
elic PIBs were crosslinked by moisture at room temperature in the presence
of catalytic amounts of tin(II) 2-ethyl-hexanoate. Extraction of the crossl
inked samples with hexanes resulted in negligible soluble content, indicati
ng essentially quantitative crosslinking.