Bleached sulfite pulp

Figure 6.10 Influence of molecular weight on the adsorption of polyethyleneimines (PEI) by a bleached sulfite pulp (PEI 10 = DP of 10 and PEI 500 = DP 500).

US military requirements and tests for wood pulp(sulfite) intended for manuf of NC are as follows(Ref 8) a)The material shall be bleached sulfite pulp from coniferous wood which has been washed to remove the purifying chemicals and formed into sheets or laps suitable for fluffing or shredding and subsequent nitration. 

Yinylogous enamine dyes are obtained by reaction of aromatic amines with mucochloric acid (2,3-dichloro-4-oxo-2-butanoic acid), followed by condensation with quaternary quinaldine. After methylation of the enamine nitrogen atom with dimethyl sulfate, the dye 5 is obtained, which dyes bleached sulfite pulp red [15]. 

If methyleneindoline-o)-aldehydes are condensed with cyclic amines substituted by an amino group in the aromatic ring, dyes are obtained that can be dimerized either by reaction with cyanuric chloride in a molar ratio of 2 1 or with phosgene. On account of their high substantivity these dyes are suitable for dyeing bleached sulfite pulp [22],... 

Figure 7 shows the samples with the lowest intensity for the 1654 cm-1 band were 8, 9, 10, and 30. These were unbleached sulfite pulp, peroxide-bleached sulfite pulp, hydrosulfite-bleached sulfite pulp, and acetylated wood section, re-... 

Dissolving pulp, a bleached sulfite pulp from spruce, MbDoCell H3430 from Mb och DomsjS AB, Omskoldsvik, Sweden. 

Grease-proof pulp, a bleached sulfite pulp from spruce, with high hemi-cellulose content, from Billerud-Uddeholm AB, Saffle, Sweden. Ethyl cellulose, three samples prepared from alkali cellulose and ethyl chloride to low degrees of substitution (DS) about 0.25, 0.4 and 0.6 ethyl ether groups per glucose unit. 

Grafting of dissolving pulp (MDC) and grease-proof pulp (GP) (both are bleached sulfite pulps from spruce) and low-substituted ethyl cellulose (EC) and hydroxyethyl cellulose (HEC), all samples in never-dried state, with acrylonitrile (AN) using Mn +ions, complexed with pyrophosphate ip n inin amr >s... 

Other minor pulp constituents, the resins or extractives, also have pronounced bearing on brightness reversion (161-165). In removing the resin in a bleached sulfite pulp by extracting with alcohol, Tongren found that the reversion rate was reduced (162). Giertz (163) lowered the reversion of bleached sulfite pulps to about one-third of their original value by alcohol-benzene extraction. Aalto (164) found that an ether extraction of a sulfite pulp prevented reversion to some extent. It should be borne in mind that not all resin components cause reversion, but when resin does, the resultant reversion appears to be approximately linear with the resin content. 

Bleached, soda pulp contained about the same amount of resistant xylan as bleached, sulfate pulp, and a bleached, sulfite pulp contained only a small amount (Table X). In this same study," it was observed that the resistant-xylan content was greater in an air-dried or oven-dried pulp than in the same pulp before drying (see Table XI). In agreement with the work of Meller," a reduction in resistant xylan resulted from mechanical beating or grinding. 

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