The Effects of Cooking and Bleaching on Organic Chemical Compounds in CMP Pulp and Newsprint

Yellowing and brightness stability of newsprint are very important phenomena mostly dominated by residual organic compounds. In this research, effects of cooking and bleaching on organically chemical compounds in CMP pulp and newsprint were investigated. For this purpose, samples were chosen randomly from chips, CMP pulp after cooking, after bleaching, and in newsprint produced in Mazandaran Pulp and Paper Mill (in north of Iran). At first stage, the paper flour was provided, and then the quantity of extractives was measured in percent by TAPPI standards. The GC diagram was used for identification of the compounds. The results of GC analysis showed that in chips, CMP pulp after cooking, after bleaching, and in newsprint paper, were 90, 76, 68, and 58 compounds, respectively. The common and important chemical components in the samples were benzaldehyde, dodecane, bibanzyl, 1,2-benzendicarboxylic acid, didutyl phthalate, and bis (2-ethylhexyl) phthalate. The benzaldehyde (32.56%), bis (2-ethylhexyl) phthalate (6.98%), gamma-sitosterol (4.84%) were the most abundant compounds, and the dodecanoic acid (0.14%), decane (0.18%), xylene (0.19%), and benzene,1-methyl-4-phenylmethyl (0.2%) were also present.