Chemiluminescence from the thermal and photo-oxidation of several wood pulps

Thermo- and photo-oxidative degradation of several wood pulps; thermo-mecha nical pulp (TMP), bleached sulfite pulp (NBSP), bleached kraft pulp (NBKP), unbleached kraft pulp (NUKP) and filter paper, were examined mainly by che miluminescence (CL). The CL behavior of the pulps was extremely different f rom each other and the decreasing order of its intensity was: TMP > NBKP > NBSP > NUKP > Filter paper. In the case of the bleached pulps; NBKP, NBSP a nd filter paper, the CL intensity increased with photo-irradiation time, bu t only a small change in its intensity was observed in the unbleached pulps ; TMP and NUKP. From the measurement of ultraviolet-visible (W-V) spectra o f the degraded samples, a small change in the CL intensity observed in the unbleached pulps was ascribed to the shielding and/or absorption of the emi tted light by the colored materials in the pulps. (C) 2000 Elsevier Science Ltd. All rights reserved.