The probability of presence of stacking faults in melt-grown lamellar crystals of syndiotactic polypropylene(sPP) was estimated from the half-breadth of the streaked reflections. The probability values, p, showed strong dependence on crystallization temperature, as well as on the degree of stereoregularity of the sample. When the p values were plotted against supercooling, the data were expressed by a master curve, and accordingly, the quantity of stacking faults is thought to be determined mainly kinetically, viz. by the growth rate.

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Distribution characteristics of rosin components in paper sheets tub-sized with an anionic dispersed rosin size were investigated by X-ray photoelectron spectroscopy (XPS) to elucidate the factors influencing the sizing efficiency and performance. Base handsheets subjected to tub sizing were prepared from a fines-free pulp with either aluminum sulfate or polydiallyldimethylammonium chloride (PDADMAC). Sizing degrees of tub-sized sheets increased with an increase in aluminum content of the sheets, and good sizing response also appeared in tub-sized sheets only by adding much smaller amounts of PDADMAC than those of aluminum sulfate in the base sheet-making. On the other hand. tub-sized sheets without any cationic additives showed nearly no sizing effect. These results indicated that the cationic compounds, being not limited to aluminum ones, in paper sheets were indispensable for the effective sizing appearance of the surface-sized sheets. These tub-sized sheets were applied to two-dimensional XPS analysis for estimating the rosin distribution on the sheets after vapor-phase bromination. It was suggested that the distribution states of rosin components in the sheets showing poor sizing were distorted by rewetting treatment of the sheets, however, the rosin distribution in well-sized sheets almost remained unchanged, and thus preventing the localization of rosin components by water penetration into paper sheets was a predominant factor to improve the sizing efficiency after the size retention. Possibly, the cationic compounds on pulp fibers must play a significant role to uniformly settle the anionic rosin particles to the fiber surfaces.

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The dyeing behaviors and changes in fiber structure in supercritical CO₂ fluid for several types of high-speed spun and regular fully oriented poly (ethylene terephthalate) (PET) fibers were compared. At lower temperature and pressure, the high-speed spun fibers, which had inherently larger crystallite sizes and lower birefringence, showed a larger dye uptake than the other fibers. However, when the supercritical conditions were elevated to 125°C and 23 MPa, the dye uptake of both types increased markedly and the difference in dye uptake between the fibers became small. This suggests that the swelling of fibers in supercritical CO₂ fluid exceeded a certain degree and then the diffusion of dye molecules was promoted. The swelling also promoted the rearrangement of molecular chains. The combination of the high speed spinning technique and the supercritical CO₂ fluid treatment can provide a new PET fiber with both larger crystallite sizes and higher molecular orientation in the amorphous regions.

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