No abstract

Starch was isolated from a non‐conventional source, Alstroemeria tubers and its physicochemical properties were evaluated. Commercial potato starch was used for comparison. The chemical compositions of the starches were similar, except in ash, protein, and lipids contents, where Alstroemeria showed lower values compared to potato. Starch recovery ratio for Alstroemeria was 86.4%. AM content and degree of crystallinity were similar. Granule size distribution for Alstroemeria was narrower compared to potato. The swelling properties of Alstroemeria were higher than for potato, increasing as temperature increased. Alstroemeria exhibited higher peak viscosity, breakdown and final viscosity; and lower gelatinization and pasting temperature compared to potato. AP MW and branch chain‐length distribution were studied. Alstroemeria had higher molar mass (Mw), gyration radii (Rz), and density (ρ) compared to potato. Potato starch had a higher proportion of intermediate/short chains (DP 13‐24) and Alstroemeria starch had a higher proportion of long chains (DP ≥ 37).

No abstract

No abstract

SiC nanofibers were prepared by using polymer blend and melt-spinning techniques. Polycarbosilane (PCS) as a SiC precursor polymer was dispersed finely in novolac-phenolic resin (PF) as a carbon precursor polymer with a ratio of PCS/PF=3/7. The polymer blend was melt-spun continuously. The fibers were then soaked in an acid solution in order to stabilize them (to convert into an infusible state) and finally heat-treated at 1000°C. The resulting fibers consisted of PF-derived carbon matrix including elongated nanofibers derived from PCS. Finally, the fibers were oxidized with nitric acid to remove the carbon matrix, and the released nanofibers were collected with a membrane filter. The resulting nanofibers were several 100 nm in diameter and 100 μm or more in length. They were amorphous and contained a large amount of oxygen. A part of the nanofibers was further heated to 1500°C in a graphite tube resistance furnace, resulting in crystallization into β-SiC. The behaviors were quite similar to those of a commercially available SiC fibers derived from PCS. In order to obtain optimum conditions, the processes were examined.