This article presents a method of preparing the absorbent core for an ultrathin sanitary napkin using super absorbent fiber (SAF) and viscose fiber blends with varying SAF percentages and mass per unit area (g/m2). The SAF/viscose blended carded webs were sandwiched between two layers of nonwoven fabric to integrate and encapsulate it. The prepared napkin samples showed significantly better rates of absorption for saline solution even though the glass tube wicking (gravimetric) test gave only comparable results. The saturation absorption of the core also follows a definite trend, dependent on two variables, i.e., mass per unit area (g/m2) of the core web and proportion of SAF in the core web. Based on the results, the absorption of the core has been optimized and equations have been developed for prediction of the absorption of the core from mass per unit area and the proportion of SAF in the core web. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

1 1 201Poly[2,2'-(m-phenylene)-5.5'-bibenzimidazole] (PBI) is shown to be miscible with poly(4-vinyl pyridine) over the entire composition range. Experiments were performed with commercial PBI as well as a lower molecular weight material synthesized by us. Blend miscibility is evidenced by single glass transition temperature intermediate between the pure polymers. Hydrogen bonding between the components was detected by infrared spectroscopy.

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SYNOPSISBlends of commercial poly (amic acid), LARC-PAA polymer were prepared with thermoplastic polyimide P84. The blends were shown to be miscible over a certain composition range. Chemical imidization of LARC-PAA in the blends leads to phase separation. Thermal imidization of LARC PAA in the blends was carried out in the solid state. Miscible compositions of the blend remained miscible after imidization and showed a single glass transition for each blend. Immiscible compositions after imidization remained immiscible and showed two glass transition temperatures in the DSC scans. The kinetics of thermal imidization of PAA to polyimide (PI) in the solid state were studied using FTIR. In the immiscible blend the kinetics remained unaffected while in the miscible state the rate of imidization became faster than that of the pure PAA.

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