Issue 23, 2013

Synthesis and characterization of an exact comb polyisoprene with three branches having the middle branch twice the molecular weight of the other two identical external branches

Abstract

An exact comb polyisoprene (PI) with three branches, with the middle branch having twice the molecular weight of the two other identical external branches, was synthesized by using anionic polymerization high vacuum techniques and appropriate chlorosilane chemistry. The synthetic approach involves (a) the selective replacement of the two chlorines of 4-(dichloromethylsilyl)diphenylethylene (DCMSDPE, key molecule) with identical PI chains by titration with PILi, (b) the addition of sec-BuLi to the double bond of DPE followed by the polymerization of isoprene from the newly created anionic site to form a 3-arm living star PI, (c) the selective replacement of the two chlorines of trichloromethylsilane with 3-arm star PI to form an H-shape intermediate, and (d) the replacement of the remaining chlorine of trichloromethylsilane by linear PI chains with double the molecular weight. All intermediate and final products were characterized via size exclusion chromatography, temperature gradient interaction chromatography and 1H-NMR spectroscopy. As expected, due to the inability to control the exact stoichiometry of the linking reactants, the main product (exact comb PI) is contaminated by a few by-products, despite the fact that anionic polymerization is the most efficient way to produce well-defined polymers.

Graphical abstract: Synthesis and characterization of an exact comb polyisoprene with three branches having the middle branch twice the molecular weight of the other two identical external branches

Article information

Article type
Paper
Submitted
30 Jun 2013
Accepted
11 Jul 2013
First published
12 Jul 2013

Polym. Chem., 2013,4, 5645-5655

Synthesis and characterization of an exact comb polyisoprene with three branches having the middle branch twice the molecular weight of the other two identical external branches

K. Ratkanthwar, N. Hadjichristidis, S. Lee, T. Chang, Z. Pudukulathan and D. Vlassopoulos, Polym. Chem., 2013, 4, 5645 DOI: 10.1039/C3PY00848G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements