Olefin-terminated polyisobutylene

K.L. Simison, C.D. Stokes, J.J. Harrison, and R.F. Storey, End-quenching of quasiliving carbocationic isobutylene polymerization with hindered bases Quantitative formation of exo-olefin-terminated polyisobutylene, Macromolecules, 39(7) 2481-2487, April 2006. 

A special class of lonomer in which the salt groups are only at the chain ends, i.e., telechellc ionomers, have recently received considerable attention as model lonomer systems. Kennedy and coworkers (86-88) prepared linear and tri-arm star telechellc sulfonated polyisobutylene by heterogeneous sulfonation of an olefin-terminated polyisobutylene with acetyl sulfate. Omels et... 

Analysis of the C z and C e olefin mixtures by gas chromatography and/or NMR indicated that in both cases the internal isomers were the predominant product. With all the alkylaluminum coinitiators the ratio of internal to terminal olefin was 3 1. Product characterization data are shown in Table 1. Number average molecular weights of polyisobutylenes were determined using a Hewlett-Packard 503 high speed membrane osmometer at 37° C and toluene solvent. Intrinsic viscosities were obtained with a Ubbelohde capillary viscometer at 30° C in cyclohexane solvent. The viscosity average molecular weights were calculated... 

THF) of the chlorine-terminated products led to olefin telechelic derivatives which in turn yielded many potentially useful materials (14). Thus hydroboration (a quantitative reaction) gave rise to new polyisobutylene-based diols and triols which in combination with isocyanates gave unique polyurethanes ... 

Fundamental studies directed toward the elucidation of the mechanism of olefin i.e.f isobutylene, polymerizations yielded a new method for the synthesis of novel linear and tri-arm star telechelic polymers and oligomers [1,2]. The synthesis involves the use of bi- or tri-functional initiator/transfer agents, so called inifers (binifers and trinifers), in conjunction with BCI3 coinitiator and isobutylene, and gives rise to polyisobutylenes carrying exactly two or three terminal -CH2-C(CH3)2Cl groups. These liquid telechelic polyisobutylene chlorides can be readily and quantitatively converted to telechelic polyisobutylene di- or tri-olefins [2,3] which in turn can quantitatively yield by hydroboration/oxidation telechelic polyisobutylene di- and triols [4,5]. 

Poly (olefin-ester) multiblock copolymers belong to a quite new and fast developing class of polyester elastomers [58-60]. The copolymer with PBT rigid segments and flexible polyisobutylene (PIB) segments was prepared by polycondensation in the molten state with DMT, BD, and functionalized PIB, in the presence of titanium tetrabutoxide as catalyst. a,o -Dianhydride [58] and dihydroxyl-terminated PIB of molecular weights 1000, 2200, 4800, and 10000 g/mole were used (Schemes 17 and 18). A multiblock copolymer with PBT and... 

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