Synthesis of Well-Defined Three-Arm Star-Branched Polystyrene through Arm-First Coupling Approach by Atom Transfer Radical Polymerization

Syed Shahabuddin,Norazilawati Muhamad Sarih,Sharifah Mohamad,Fatem Hamime Ismail

doi:10.1155/2015/961914

Syed Shahabuddin, Norazilawati Muhamad Sarih + Show 2 more

Open Access

https://doi.org/10.1155/2015/961914

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Abstract

Here we describe a simple route to synthesize three-arm star-branched polystyrene. Atom transfer radical polymerization technique has been utilized to yield branched polystyrene involving Williamson coupling strategy. Initially a linear polymeric chain of predetermined molecular weight has been synthesized which is further end-functionalized into a primary alkyl bromide moiety, a prime requisition for Williamson reaction. The end-functionalized polymer is then coupled using 1,1,1-tris(4-hydroxyphenyl)ethane, a trifunctional core molecule, to give well-defined triple-arm star-branched polystyrene.

Highlights

Facile and simple experimental conditions of radical polymerization make atom transfer radical polymerization (ATRP) a technique of significant current interest
A common goal for the polymer chemist involved in the synthesis of polymers with controlled branched architectures is to control molecular parameters such as molecular weight, distribution of molecular weight, dispersity (Đ), and branching pattern, as these parameters have a significant influence on the physical properties of the polymer
Atom transfer radical polymerization (ATRP) is a technique which has seen significant interest since it was first established in the mid-1990s and has seen significant advances including various metal catalyzed radical polymerization techniques since this time [9, 10]

Summary

Introduction

Facile and simple experimental conditions of radical polymerization make atom transfer radical polymerization (ATRP) a technique of significant current interest. For the synthesis of regular stars shaped polymers, this technique has been proven very effective and sequences of well-defined star polymers with precise arm numbers have been fruitfully synthesised by atom transfer radical polymerization (ATRP) [12,13,14], ring-opening polymerization (ROP) [15,16,17], reversible addition fragmentation chain transfer (RAFT) [18], anionic polymerization [19, 20], and group transfer polymerization [21]. A divergent approach has been utilized by Gnanou et al for the synthesis of dendrimer-like polystyrene through ATRP They were successful in achieving third-generation branched dendritic polystyrene using multifunctional initiators based on calixarene. Conversion of alkyl brominated linear polystyrene involving effective Williamson coupling reaction with a trifunctional core to give a triarm branched star shape polymer is the second and the final step. The simplicity of the reaction steps makes it an effective tool for the production of branched polymers

Experimental Section

Results and Discussion

Conclusions