Polymere ester von Säuren des phosphors, 5. Ringöffnende polymerisation des 2-phenoxy-1,3,2-dioxaphospholan durch Michaelis-Arbuzov-reaktion

✍ Scribed by Vogt, Walter ;Ahmad, Nasim U.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1977
• Weight: 879 KB
• Volume: 178
• Category: Article
• ISSN: 0025-116X
• DOI: 10.1002/macp.1977.021780613

✦ Synopsis

Abstract

2‐Phenoxy‐1,3,2‐dioxaphospholane (14) was polymerized by benzyl halogenides at temperatures between 120 and 200°C. It was found that the main chain consists predominantly of unexpected ethylene 1,2‐ethanediphosphonate units 7; only about 10% of the monomer was incorporated as the expected 2‐hydroxyethanephosphonate structure. An insertion mechanism, proposed by Harwood and Patel for the analogous polymerization of 2‐phenyl‐1,3,2‐dioxaphospholane, does not agree with our experimental results. A hypothesis is developed involving a two step addition process, which exclusively occurs at the chain end. Alternating, one monomer molecule is added by a normal Michaelis‐Arbuzov‐reaction, and then a second molecule is added followed by an intermediate 1,2‐shift of the endstanding halogen cryptoanion. With benzyl bromide as initiator, the growing end shows alternating the sequences CPOCCBr (2‐bromoethyl ester) and COPCCBr (2‐bromoethanephosphonate).