Functional modified fibers

Synthetic fibers for general use cannot meet the requirements of commercial values. Modified fibers with functional properties, such as antibacterial fibers, UV-protection... 

The process of Cr (VI) complexation of modified carbon fibers was studied. Modified carbon fibers were obtained by the liquid-phase oxidation of the concentrated nitric acid and diphenyl carbazide solution impregnation. The morphology of starting and modified fibers surface was studied using atomic-force microscopy. Sizes of complexes formed in the process of interaction of chromium with the functional and analytical group of the diphenyl carbazide chelating reagent, was established. 

Fig. 23. Normalized maximum interfacial shear stress obtained from a nonlinear finite element analysis (NLFEM), empirical (ITS) equations, shear-lag and modified shear-lag equations as a function of fiber volume fraction [110].

Sericin is recovered during the various stages of producing raw silk. Sericin is oxidation-, bacterial-, and UV-resistant, and it absorbs and releases moisture rapidly. Sericin can be cross-linked, copolymerized, and blended with other macromolecular materials, especially artificial polymers. The materials modified with sericin and sericin composites are useful as degradable biomaterials, biomedical materials, polymers, functional membranes, fibers, and fabrics [26]. 

A novel procedure was developed to improve psyllium functionality by conducting a solid-state enzyme reaction. The procedure requires no special equipment/operation (such as freeze dry) and could be carried out without using any additional chemicals. To evaluate the solid-state enzymatic procedure, modified psyllium preparations were produced under selected reaction conditions, and analyzed for their water-absorbing capacity, gelling capacity, particle surface structure, and soluble and insoluble fiber contents. The results showed that structural modification improved psyllium functionality. Modified psyllium preparations had reduced water-absorbing capacity and less gelling ability. The reduced water-absorbing capacity may be explained by the decreased surface area of psyllium particles. In addition, the solid-state enzymatic treatments had much less effects on soluble fiber contents than the liquid phase enzymatic reactions. 

The lambda type is nongelling, and functions as a thickner. Iota-carrageenan has been recommended (45) for use in formulating low fat ground beef due to its abihty to retain moisture, especially through a freeze—thaw cycle which is typical for ground beef patties. Oat bran and oat fiber can also be used to improve moisture retention and mouth feel. Modified starches can be used as binders to maintain juiciness and tenderness in low fat meat products. Maltodextrins (dextrose equivalent less than 20) may be used as binders up to 3.5% in finished meat products. Other carbohydrates such as konjac flour, alginate, microcrystalline cellulose, methylceUulose, and carboxymethylceUulose have also been used in low fat meat products (see CELLULOSE ETHERs). 

Tensile Properties. Tensile properties of nylon-6 and nylon-6,6 yams shown in Table 1 are a function of polymer molecular weight, fiber spinning speed, quenching rate, and draw ratio. The degree of crystallinity and crystal and amorphous orientation obtained by modifying elements of the melt-spinning process have been related to the tenacity of nylon fiber (23,27). 

---