Polymerization of isobutylene initiated by tert-butyl chloride-boron trichloride. Synthesis of α-tert-butyl-ω-chloro-poly(isobutylene) and α-tert-butyl-ω-isopropenylpoly(isobutylene)

Thermally induced polymerization of isobutylene in the presence of SnCl4: Kinetic study of the polymerization and NMR structural investigation of low molecular weight products

“…It can be seen that the spectra of samples 1 and 2 are similar and markedly different from that of Oppanol B3. In our previous article,33 we assigned for Oppanol B3 two lines at 4.62 and 4.82 ppm to methylene protons in terminal structure A and the line at 5.13 ppm to methine proton in terminal structure B (see Scheme ), which is in accordance with other studies 19, 32, 34, 37–40. The spectra show that structures A and B also exist in samples 1 and 2; however, in contrast to Oppanol B3, the relative population of A structures is higher in these samples as can be seen from relative intensities of the corresponding lines.…”

“…Samples prepared with stannic chloride at temperatures from −20 to 60 °C (Table I) contain no chlorine in terminal groups. This was verified by elemental analysis and by 1 H NMR spectra in which bands at 1.66 and 1.92 ppm belonging to methyl and methylene protons of the CH 2  C(CH 3 ) 2 Cl type terminal groups21, 34 were not found. Thus, PIBs with terminal unsaturation only are formed under the conditions described in this article.…”

One‐pot synthesis of isocyanate and methacrylate multifunctionalized polyisobutylene and polyisobutylene‐based amphiphilic networks

“…Figure 3 also shows resonances in the region 4.6–5.2 ppm, the range typical of unsaturated terminal groups of PIB,25, 28, 30, 31 where endo type CHC(CH 3 ) 2 (signal e) generally prevails over exo types 10. The resonance of methyl protons from C(C H 3 ) 3 PIB head‐groups10, 25, 32 (signal f) can be also found in the spectrum. The average molar ratio of PIB and MA monomeric units ( r = [PIB]/[MA]) was determined from integrated intensities of PIB protons and methacrylate OCH 2 and CH 2  protons (signals b and a, respectively).…”

“…A slightly higher intensity of signal d can be due to the fact that also methylene protons from C H 2 C(CH 3 ) 2 Cl and C H 2 C(CH 3 )CH 2 polyisobutylene terminal groups25 as well as methyl protons from C(C H 3 )CH 2 methacrylate terminal groups contribute to this signal. Figure 3 also shows resonances in the region 4.6–5.2 ppm, the range typical of unsaturated terminal groups of PIB,25, 28, 30, 31 where endo type CHC(CH 3 ) 2 (signal e) generally prevails over exo types 10. The resonance of methyl protons from C(C H 3 ) 3 PIB head‐groups10, 25, 32 (signal f) can be also found in the spectrum.…”

“…Toluene, tetrahydrofuran (THF), and n ‐heptane were dried over CaH 2 and distilled under argon just before use. Argon was dried and freed from traces of oxygen 25. Oppanols B200 and B12 (both BASF) were used as received.…”