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On the Interaction of UV Screens with the Lignocellulosic Matrix
Author(s) -
Peng Philip P.,
Argyropoulos Dimitris S.
Publication year - 2000
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2000)0710149otious2.0.co2
Subject(s) - matrix (chemical analysis) , chemistry , biochemical engineering , engineering , chromatography
In this report, we describe our attempt to understand the photochemical interactions that occur between dihydroxybenzophenone (DHB)‐based UV screens and lignin when high‐yield pulps are treated with such materials. Milled wood lignin (MWL) and filter paper were used as models, and various irradiation protocols were carried out in the presence and absence of UV screens. After irradiation, the lignin and the UV screen were extracted and the products analyzed. These experiments showed that upon irradiation, fragments of MWL‐containing chromophores were linked to cellulose via an acid‐labile linkage. In the presence of UV screens, these reactions were minimized. Molecular weight measurements of the extracted lignin showed that the MWL is degraded upon solid‐state irradiation. The samples that contained UV screens showed a reduced tendency to degrade. Using quantitative 31 P NMR, it was possible to probe further the detailed structural changes that occurred in MWL during irradiation. In general, DHB‐based UV screens and derivatives were found to interact actively with MWL when irradiated.