Synthesis and characterization of a novel octa-arm polyisobutylene star

Summary The synthesis and characterization of a novel telechelic star consisting of a well defined C-pentyl-calix4]1,3-dicumyl alcoholarene (3) core out of which radiate eight well-defined polyisobutylene arms, each fitted with an allyl terminus is described. The synthesis was accomplished by a core-first method, by inducing the living polymerization of isobutylene by 3 in conjunction with BCl₃-TiCl₄ coinitiators. The product was characterized by GPC coupled with laser light scattering (LLS) and referactive index (RI) detectors, and by ¹H NMR spectroscopy. Quantitative functionality analysis indicated the presence of exactly eight PIB arms per molecule. Received: 3 April 2001 / Revised version: 22 June 2001 / Accepted: 22 June 2001