Application of multicriterial optimization for determination of crystallinity degree of semicrystalline polymers

ABSTRACT:The structural parameters and strength properties of a new generation of polyacrylonitrile fibers have been analyzed. These fibers, after being carbonized, can be used in biomaterial engineering. They are characterized by a high tensile strength of 31-43 cN/tex. An advantageous influence of nanoparticles added to the fiber matter on the degree of crystallinity has been found. When nanoparticles of hydroxyapatite are incorporated into these fibers, their degree of crystallinity increases by about 5%.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Analysis of the structural parameters of polyacrylonitrile fibers containing nanohydroxyapatite

Mikołajczyk

Rabiej

Boguń

2006

“…To this aim, a theoretical curve was constructed, composed of functions related to individual crystalline peaks and amorphous halos. The theoretical curve was fitted to the experimental one using a multicriterial optimization procedure and a hybrid system which combines a genetic algorithm and a classical optimization method of Powell 24. Both crystalline peaks and amorphous halos, were represented by linear combination of Gauss and Lorentz profiles.…”

Section: Methodsmentioning

confidence: 99%

Effect of formation conditions on the structure and properties of nanocomposite alginate fibers

Boguń¹,

Mikołajczyk²,

Rabiej³

2009

ABSTRACT:The conditions for producing nanocomposite fibers composed of calcium alginate, containing a hydroxyapatite nanoadditive were devised and the rheological, sorptive, and strength properties of these fibers, as well as their porous and supramolecular structure were subjected to analysis. It has been concluded that the presence of the HAp nanoadditive in the material of alginate fibers decreases their susceptibility to distortion in the drawing stage, which results in their tenacity properties being lower by 2cN/tex than of the fibers with no nanoadditive. The obtained nanocomposite fibers are characterised by a tenacity value exceeding 26 cN/tex, accompanied by high sorptive and water-retention properties of 90% and the even distribution of the nanoadditive on the fiber surface.

“…The analysis of the WAXS diffraction curves and the calculation of the crystallinity degree were carried out with the computer program OpiFit17, 18 according to the procedure described in ref 19…”

Section: Resultsmentioning

confidence: 99%

Comparative analysis of the structural parameters and strength properties of polyacrylonitrile fibers containing ceramic nanoadditives

Mikołajczyk¹,

Boguń²,

Rabiej³

2007

ABSTRACT:The structural parameters and strength properties of three types of new-generation precursor polyacrylonitrile fibers are comparatively analyzed. These fibers, after the carbonization process, can be used as implants supporting the process of bone reconstruction. They are characterized by a high tenacity ranging from 21 to 41 cN/ tex. Tests and measurements have shown that the presence of nanoadditives causes a clear increase in the degree of fiber crystallinity. Moreover, the tenacity of the fibers can be considerably increased by the grinding of nanoadditive agglomerates with ultrasound.