Below mentioned changes were observed in the quality of N-BKP and L-BKP after stored 20 days under the following conditions.
(a) Applying of ultraviolet rays for 3 hours per day.
(b) Applying visible ray.
(c) In dark box.
Table 1 and table 2 are the results of the observation after 10 days and 20 days treatments respectively, the summary is as following;-
Bursting strength; decreased with the aging.
Tensile strength; decreased with the aging.
Brightness; almost unchanged.
α-cellulose; almost unchanged.
β-cellulose; slightly increased.
1% NaOH sol, solubility; slightly increased.
10% NaOH sol, solubility; slightly increased.
Carboxyl group; distinctly increased.
It seems that brightness value decreased due to the impurity or imperfect washing.
In respect to paper treatment :
Table 5 and 6. show the data of kraft paper exposed 20 days in the open air. According to these tables undermentioned phenomena were observed in the case of air aging;-
(1) Bursting strength decreased about 30%;
(2) Both 1% and 10% NaOH sol, solubilities increased by more than 250% of initial value.

View full abstract

Dimethyl sulfide is easily oxidized by ozone at low temperature. In ozone oxidation, residue from ozone is O₂ only, and so recovery of reaction products is easy. In this report, we describe the outline of ozone oxidation and then the purity of dimethyl sulfoxide, by gas chromatograph and IR spectrum.
Ignition point of dimethyl sulfide in air is 206°C and in oxygen is 204.5°C. The difference between the former and the latter is small.
Dimethyl sulfide composes the explosion mixture with O₂. In this meaning, we would describe the ozone oxidation condition.

View full abstract

1) Acrylamide (AA) grafted fiber gives a globular swelling by treating with 10% caustic soda and diluted cuprammonium solution, but methyl methacrylate (MMA) grafted fiber diminishes the degree of swelling with increasing degree of grafting. On the other hand, the former dissolves instantly in conc. cuprammonium solution, while the latter becomes insoluble with the increase of degree of grafting.
The shapes of swollen fibers are related to the estimated results of the hydrophilic or hydrophobic nature of grafted pulp based on the nature of grafted polymer toward water and the water retention value of grafted pulp in the previous paper.
2) Papermaking properties depend on the water retention value of grafted pulps, i.e., the paper made from hydrophilic AA grafted pulp gives higher sheet density, but in the case of hydrophobic MMA grafted pulp gives a porous sheet. Factor governing the strength of these sheets is the fiber-fiber bonds (sheet density is used as a measurement of bonded area instead of scattering coefficient) rather than individual fiber strength (zero span test is unsuitable).
3) Paper strength is affected by the beaten state of grafted pulp, and the ease or difficulty of beating is related to the degree of the affinity of the grafted polymer toward the beating media and the degree of grafting of grafted pulp.
4) Physical properties of the papers made from acrylic ester grafted pulps beaten in water or acetone are affected by the physical properties of grafted polymer.
5) Tensile strength of the paper made from methacrylic ester grafted pulp is affected by the environ-mental temperature.
6) According to the results of tensile test of these papers immersed in water, ethanol, acetone, and benzene, fiber-fiber bonds can be classified into the following three types, fellow celluloses, cellulose-grafted polymer, and fellow grafted polymers.

View full abstract