Depolymerization of Cellulose by Electron Beam

The depolymerization of cellulose by means of a high energy irradiation was studied using GGCo gamma-ray or electron beam as an irradiation source. It was found that the number of broken bonds calculated from number average degree of polymerization (Pa) of irradiated samples is linearly proportional to the absorbed doses, and an experimental equation applicable to both types of irradiation was established. By the use of this equa-tion, the relative absorbed dose distribution within the pulp sheets in pile irradiated with electron beams was determined from the Pm values for each sheets. Furthermore, in order to make the absorbed dose distribution narrower the utilization of electron filters as well as back-scattering bodies were studied for an electron beam at 2 and 0.5 MeV, respectively. Although both techniques are useful to prevent the samples from causing wide absorbed dose distribution, it may be to note that higher irradiation efficiency (95 % or more) and narrower absorbed dose distribution are achieved using single side irradiation method of the latter. The various samples thus irradiated were nitrated and characterized successfully for the molecular weight distributions using gel permeation chromatography. I