Włodzimierz Biniaś

Application of Raman Spectroscopy for Evaluation of Chemical Changes in Dibutyrylchitin Fibres

Microporous dibutyrylchitin (DBC) fibres formed by means of a dry-wet method were treated with aqueous solutions of potassium hydroxide. By applying various parameters of the alkaline treatment, fibres can be transformed into fibres from regenerated chitin or even into chitosan fibres. In the first stage, with the application of 5% KOH solutions and temperatures ranging from 20 to 90 °C, fibres from regenerated chitin were obtained. The subsequent treatment stage with saturated KOH solutions and the temperature range 70 140 °C resulted in obtaining fibres from chitosan with different deacetylation degrees.Structural changes in the fibres occurring in the course of their chemical treatment were analysed using RAMAN spectroscopy. Raman spectra were next mathematically processed by means of GRAMS software within the range 1800 820 cm-1 in order to evaluate the changes quantitatively. A new method is described for the determination of butyrylation and deacetylation degrees of dibutyrylchitin, chitin and chitosan. Analysis of the fibres obtained carried out by means of RAMAN spectroscopy proves that in the process gradual degradation of the polymer chains takes place.

FORMATION AND PROPERTIES OF DBC/PLA MICROFIBRES

In this study, a solution of dibutyrylchitin (DBC)/polylactide (PLA) blend micro and nanofibres were successfully fabricated using blends of 2,2,2-trifluoroethanol (TFE) as solvents. Fibres were produced from the solutions by electrospinning. The DBC/PLA blend solutions in various ratios were studied for electrospinning into micro/nanofibres. The morphology of the micro and nanofibres was observed by scanning electron microscope (SEM). The biggest diameters of DBC/PLA fibres were obtained for the blended microfibres in ratios of 10/90 and 25/75. The smallest diameter was observed for pure polymers. The antibacterial properties were examined for materials obtained by electrospinning. In the experiments, materials with antibacterial properties were made. It is likely that the electrospun micro and nanofibres will be used in the native extracellular matrix for tissue engineering.

Looking for Positive Mixing Volume in Polyamide/Acrylic Rubber Blends with Use of Positron Annihilation Lifetime Spectroscopy and Other Methods

M. D bowska, J. Pig owski , T. Suzuki, J. Rudzi ska-Girulska, Cz. lusarczyk, W. Binia 4 1 Institute of Experimental Physics, University of Wroc aw, PL 50-204 Wroc aw, pl. M. Borna 9, Poland, debowska@ifd.uni.wroc.pl 2 Institute of Organic and Polymer Technology, Wroc aw University of Technology, Wybrze e Wyspia skiego 27, PL 50-370 Wroc aw, Poland, piglowski@itots.ch.pwr.wroc.pl 3 Radiation Science Center, KEK, Oho 1-1, Tsukuba-shi, Ibaraki 305-0801,Japan, 4 University of Bielsko-Bia a, Willowa Street 2, PL 43-309 Bielsko-Bia a, Poland