Effect of the Molecular Weight and Architecture on the Size and Glass Transition of Arborescent Polyisobutylenes
This article discusses the characterization of arborescent (hyperbranched) polyisobutylenes (arb-PIBs) by size exclusion chromatography and differential scanning calorimetry, in comparison with linear PIB standards. The radius of gyration (〈r〉1/2 = Rz), measured from the angle dependence of light scattering of high-molecular-weight arb-PIBs, was significantly larger than the hydrodynamic radius (Rh) from size exclusion chromatography/viscometry, and the Rh values were significantly smaller than Rh of linear PIBs. The glass-transition temperature of arb-PIBs having a branch molecular weight higher than the critical entanglement molecular weight was dependent on both the total number-average molecular weight and BR up to BR ∼ 15. A modified Fox–Flory equation is proposed to describe the effect of architecture on the thermal transition. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1770–1776, 2006
Journal of Polymer Science Part A: Polymer Chemistry
Puskas, Judit; Chen, Yaohong; Kulbaba, Kevin; Kaszas, Gabor; and Soleymannezhad, Ali, "Effect of the Molecular Weight and Architecture on the Size and Glass Transition of Arborescent Polyisobutylenes" (2006). Chemical and Biomolecular Engineering Faculty Research. 497.