Dendritic polyisobutylene

SCHEME 7.2 Reactivation of dendritic polyisobutylene (DIB) chain ends. (From Puskas, J.E., Kwon, Y., Antony, P., and Bhowmick, A.K., J. Polym. Sci. A., 43, 1811, 2005, cover page. With permission.)... 

FIGURE 7.6 Reproducibility of the synthesis of dendritic polyisobutylene capped with polystyrene blocks (SDIBS) on a pound scale. The various symbols represent different experiments (details will be published elsewhere). 

FIGURE 7.9 Architecture of dendritic polyisobutylene capped with polystyrene blocks (SDIBS). 

FIGURE 7.14 Size exclusion chromatography (SEC) trace of a dendritic polyisobutylene (DIB) (05-DNX-190-3 in Table 7.3). 

Characteristic Data of Selected Dendritic Polyisobutylene Capped with Polystyrene Blocks (SDIBS)-Hydroxide (OH) Samples... 

Puskas, J.E. BiocompatibiUty studies of novel dendritic polyisobutylene-based block copolymers, Polym. Prepr., 45, 412- 13, 2004. 

Among the many unusual properties that the arborescent architecture leads to, most notable is the discovery that block copolymers with a high MW dendritic (arborescent) polyisobutylene core and poly(para-methylstyrene) end blocks can manifest themselves either as a rubber, or as a plastic, depending on their environment (Figures 7.16 and 7.17). The behavior is thermally irreversible. 

Sui, C., McKenna, G.B., and Puskas, J.E. Nonlinear viscoelastic response of dendritic (arborescent) polyisobutylenes in single- and reversing double-step shearing flows, J. Rheol, 51, 1143, 2007. 

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