Novel thermoplastic elastomers based on arborescent (dendritic) polyisobutylene with short copolymer end sequences

Abstract

This article presents the synthesis and initial characterization of polymers having a high molecular weight dendritic (arborescent) polyisobutylene (arbPIB) core and short end sequences composed of copolymers of isobutylene with isoprene, p‐methyl styrene, or cyclopentadiene. The first stage of the polymerizations was controlled/living (i.e., no chain transfer or irreversible termination were detected) and the process was reproducible. The hydrodynamic radii of arbPIBs were measured by viscometry and quasi‐elastic light scattering, and good agreement between the two methods is demonstrated for the first time in this paper. Sequential addition of the second monomer(s) led to the formation of short copolymer end sequences. We have discovered that regardless of the Tg of the copolymer end blocks, the new block copolymers exhibited TPE properties, which were improved by carbon black and silica fillers to a great extent. These novel PIB‐based TPEs are promising new biomaterials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1148–1158, 2009

Applying Multidimensional Method of Moments for Modeling and Estimating Parameters for Arborescent Polyisobutylene Production in Batch Reactor

“…Fréchet et al introduced the concept of self‐condensing vinyl polymerization (SCVP). Later this concept was extended into inimer (IM)‐type homo‐ and copolymerization . The term inimer refers to a small molecule that contains a functional group that can initiate polymerization, as well as a vinyl group that can be consumed by propagation ( ini tiator‐mono mer ).…”

Advanced Monte Carlo Model for Arborescent Polyisobutylene Production in Batch Reactor

“…Figure shows a typical inimer (IM) molecule, which has a vinyl group that can polymerize and a chloride group that can be removed to initiate carbocationic polymerization. By copolymerizing this IM with isobutylene (IB), Puskas et al developed a simple method to produce polyisobutylene (PIB) with an arborescent or tree‐like structure and used this new material as a core to produce block copolymers with polystyrene end blocks. This block copolymer has excellent mechanical properties, biocompatibility, and biostability, making it a very promising material for human implantation, especially for breast implants …”

“…Figure shows a simplified reaction mechanism of “one‐pot” living copolymerization of IM and IB developed by Puskas et al The first step is an exchange reaction that converts 4‐(2‐methoxyisopropyl)styrene (MeOIM) to IM. A large excess of TiCl 4 , which is a Lewis acid (LA), is often used in the experiments to ensure that this exchange reaction goes to completion and that there is sufficient LA to initiate the living carbocationic polymerization.…”

Monte Carlo Model for Arborescent Polyisobutylene Production in the Batch Reactor

“…The concept of “one‐pot” living homopolymerization of IM molecules was first introduced by Fréchet et al in 1995, which they named self‐condensing vinyl polymerization (SCVP) . Later, self‐condensing vinyl copolymerization (SCVCP) of inimers and vinyl monomers was performed experimentally …”