Wavelength sensitivity of the photodegradation of polybutyleneterephthalate-block-polytetramethyleneglycol (PBT-block-PTMG)

Abstract

The wavelength dependence of the photodegradation of polybutyleneterephthalate-block-polyterrameryleneglycol; (PBT-block-PTMG), has been investigated using monochromatic radiation supplied from the Okazaki Large Spectrograph. From our results, we conclude the following: Main-chain scission occurs when PBT-block-PTMG is exposed to a wavelength of 320 nm or shorter. Moreover, main-chain scission is greatly enhanced for a wavelength of 310 nm. The main photodegradation products are formate, propyl and aldehyde end groups and aliphatic ester groups. The threshold wavelength for the photodegradation of PBT-block-PTMG is ca. 310 nm. The photodegradation of PBT-block-PTMG is induced through hydrogen abstraction by carbonyl groups in n,π* excited states. © 2012, The Society of Polymer Science.