Date of Award

4-1995

Degree Name

Bachelor of Science

Department

Paper Science and Engineering

First Advisor

Raja Aravamuthan

Abstract

Research work to date has shown dimethyldioxirane to be a very powerful, yet highly selective oxidant. Dimethyldioxirane bleaching may become more important in the future with legislative restrictions on chlorine based bleaching agents as it contains no chlorine. Most work with dimethyldioxirane to date has concentrated on short sequence bleaching, or the use of peroxymonosulfate as a pre-treatment to improve oxygen delignification. The goal of this study was to develop a full sequence bleaching containing only dimethyldioxirane and other chlorine free bleaching agents that matched the brightness and strength characteristics of comparable chlorine dioxide based full sequences. Dimethyldioxirane was found to match the strength, but not the brightness of, chlorine dioxide. As well, dimethyldioxirane may be harsher on cellulose than chlorine dioxide. Additional optimization may allow dimethyldioxirane to perform as well as chlorine dioxide. It was seen that increased brightnesses were achieved by using optimum conditions and a step-wise chemical addition. As well, the addition of peroxide to dimethyldioxirane stages may increase brightness.

Share

COinS