α,ω‐glycols from isobutylene and some derived block copolymers

Abstract

Butyl rubber containing 2 mole‐% of isoprene was ozonized and reduced producing polyisobutylene glycol. Hydroxyl equivalent determinations on the glycol and elemental analyses of the chain extended polymers indicate the glycol to be difunctional. Possible structures of the glycol and extended polymer are suggested.

The use of radical polymerization in the synthesis of telechelic oligomers

“…1 shows plots of o(1/X n )/o[S] against 1/[M] as required by Eq. (2). As predicted, the results fitted a linear relationship that passed through 0,0.…”

“…The concept of using the fragments of ozonolytic chain degradation as telechelic oligomers was first introduced by Marvel for the synthesis of telechelic oligoisobutene [2,3]. We have applied this method to the cleavage of diene copolymers produced by radical copolymerization, as shown in Scheme 1.…”

α,ω‐Glycols from copolymers of isobutylene and 2,5‐dimethyl‐2,4‐hexadiene

“…A similar cleavage reaction performed on butyl rubber containing 2 mole-% isoprene has been reported previously. 2 Copolymers having inherent viscosities close to 0.4 were prepared by treating mixtures of isobutylene and 2,5-dimethyl-2,4-hexadiene with 1.0-2.2% boron trifluoride in petroleum ether solution a t -78°C. The presence of unsaturation in the copolymers shown in Table I is not evident from the NMR or infrared spectra.…”