𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Photoreversible Chain Extension of Poly(ethylene glycol)

✍ Scribed by Scott R. Trenor; Timothy E. Long; Brian J. Love

Book ID
102486588
Publisher
John Wiley and Sons
Year
2004
Tongue
English
Weight
187 KB
Volume
205
Category
Article
ISSN
1022-1352

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Summary: Coumarin containing poly(ethylene glycol) monols and diols were prepared in a telechelic fashion using quantitative end group esterification. The coumarin modified poly(ethylene glycol) monols and diols were solution cast into films (1 to 15 ΞΌm) and chain extended via the dimerization of the coumarin derivatives with UVA (>300 nm) light irradiation. The coumarin‐modified PEG diol doubled in molecular weight, and the molecular weight distribution increased from 1.17 to 2.75 upon exposure to 110 J · cm^βˆ’2^ of UVA light. The chain extended poly(ethylene glycol)s were subsequently converted to their original molecular weight via the photocleavage reaction of the coumarin dimer at 254 nm with less than 2 J · cm^βˆ’2^. The photoreversible chain length modulation was monitored utilizing GPC, DSC and UV‐Vis spectroscopy.

Molecular weight modulation of COU‐PEG‐COU.

magnified imageMolecular weight modulation of COU‐PEG‐COU.

πŸ“œ SIMILAR VOLUMES

End-group effect on chain conformation o
End-group effect on chain conformation of poly(propylene glycol) and poly(ethylene glycol)
✍ Sunghoe Yoon; William J. MacKnight; Shaw Ling Hsu πŸ“‚ Article πŸ“… 1997 πŸ› John Wiley and Sons 🌐 English βš– 138 KB πŸ‘ 2 views

A comparison is made of the chain conformational distribution of hydroxyterminated poly(propylene glycol) (PPG) and poly(ethylene glycol) (PEG) with their methoxy-terminated derivatives. The significant end-group dependence on the glass transition temperature in PPG was observed by differential scan