Photodegradation mechanisms in
(PBNePTMG). II: wavelength sensitivity of
, Daisuke Nakamura
, Hitoshi Ueno
, Fujio Ohishi
Department of Materials Science, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka city,
Kanagawa 259-1293, Japan
TOYOBO Research Center Co., Ltd., 2-2-1 Katata, Ohtsu city, Shiga 520-0292, Japan
Received 20 July 2004; accepted 3 October 2004
Available online 8 January 2005
The wavelength dependence of the photodegradation of poly(2,6-butylenenaphthalate-co-tetramethyleneglycol) (PBN-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 PBN-PTMG is exposed to wavelengths of 380 nm
Remarkably, the formate, propyl, aldehyde and the aliphatic ester groups are all formed by monochromatic irradiation at
370 nm and 380 nm. The proportion of the gel fraction is greatly enhanced when radiation is carried out with monochromatic light
of ca. 380 nm.
The threshold wavelength for the photodegradation of poly(2,6-butylenenaphthalate-co-tetramethyleneglycol) is ca. 380 nm.
Ó 2004 Elsevier Ltd. All rights reserved.
Keywords: Poly(2,6-butylenenaphthalate-co-polytetramethyleneglycol); Photodegradation; Monochromatic irradiation; Threshold wavelength
In recent years, a thermoplastic polyester elastomer
composed of poly(2,6-butylenenaphthalate) and poly
(tetramethyleneglycol) (PBNePTMG), has been devel-
This product has, compared to the thermoplastic
polyester elastomer PBTePTMG (poly(butylenetereph-
thalate-co-tetramethyleneglycol)), improved resistance
to heat, chemicals, oil and water.
In our previous paper , we reported on the
photodegradation of PBNePTMG resulting from irra-
diation by polychromatic light. In that work, it became
clear that ester bonds are formed on the soft-segment
and that formate, propyl, aldehyde and hydroxyl groups
result from main chain scission (Fig. 1). However,
studies on the wavelength dependence of PBNePTMG
photodegradation have not yet been reported. Pre-
viously, we investigated the wavelength dependence of
PBTePTMG photodegradation by using cutoﬀ ﬁlters
. In that paper, it was shown that the threshold
* Corresponding author. Fax: C81 463 58 9684.
E-mail address: email@example.com (Y. Nagai).
0141-3910/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved.
Polymer Degradation and Stability 88 (2005) 256e260