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Polyester binders for wood containing benzotriazole and HALS light stabilizers
Author(s) -
Sundell P.,
Sundholm F.
Publication year - 2004
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.13672
Subject(s) - benzotriazole , stabilizer (aeronautics) , polyester , penetration (warfare) , materials science , composite material , softwood , fourier transform infrared spectroscopy , polymer chemistry , chemical engineering , mechanical engineering , operations research , engineering , metallurgy
Three new polyester binders containing either benzotriazole‐type or hindered amine light stabilizers (HALS)‐type light stabilizers were synthesized. The binders were characterized by 13 C and 1 H NMR, FTIR, UV‐VIS spectroscopy, and size exclusion chromatography. It was found that it was possible to bind a benzotriazole‐type light stabilizer to the polymer backbone of the binder if a suitable group was present in the stabilizer. However, there was no proof that the HALS‐type stabilizer was bound to the binder. The average penetration depth of the binders into the radial surface of pine wood was mainly below 480 μm into earlywood and below 2500 μm into latewood. The average penetration depth into the tangential surface was around 1000 μm in the earlywood and around 2500 μm in the latewood. Artificial weathering causes a binder‐treated wood surface to darken independently of the binder used. The yellowness of the irradiated pine samples increased at the beginning of the exposure but decreased during longer exposure times. The benzotriazole stabilizer, Tinuvin 213, protected the surface of wood quite well; the other stabilizers were poor. The wood surface became rougher in appearance, cracks along the microfibril orientation became pronounced, and the bordered pits were degraded in the weathered samples. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1413–1421, 2004