Well-Defined Miktocycle Eight-Shaped Copolymers Composed of Polystyrene and Poly(ε-caprolactone): Synthesis and Characterization

✍ Scribed by Gang-Yin Shi; Jiao-Tong Sun; Cai-Yuan Pan

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 607 KB
• Volume: 212
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.201100001

✦ Synopsis

Abstract

A series of well‐defined miktocycle number‐eight‐shaped copolymers composed of cyclic polystyrene (PS) and cyclic poly(ε‐caprolactone) (PCL) have been successfully synthesized by a combination of atom transfer radical polymerization (ATRP), ring‐opening polymerization (ROP), and “click” reaction. The synthesis involves three steps: 1) preparation of tetrafunctional initiator with two acetylene groups, one hydroxyl group and a bromo group; 2) preparation of two azide‐terminated block copolymers, N~3~‐PCL‐(CHC)~2~‐PS‐N~3~, with two acetylene groups anchored at the junction; and 3) intramolecular cyclization of the block copolymer through “click” reaction under high dilution. The ^1^H NMR, FT‐IR, and gel permeation chromatography (GPC) techniques are applied to characterize the chemical structures of the resulting intermediates and the target polymers. Their thermal behavior is investigated by differential scanning calorimeter (DSC). The decrease in chain mobility of eight‐shaped copolymers restricts the crystallization of PCL. magnified image