Andrzej Włochowicz

Application of Fourier-transform infrared and Raman spectroscopy to study degradation of the wool fiber keratin

Abstract Wool fibers and products made from them accompany a man almost from the dawn of history. Wool is still the most popular natural material and it is irreplaceable for ecological reasons. However, environmental pollution makes irreversible changes in the structure of wool fibers. Consequently, natural resources of quality precious materials decrease. This situation induces actions which lead to the regeneration of wool fibers. In laboratory conditions wool fiber keratin was exposed to the hydrolytic degradation process in alkaline environment and then the attempt of interruption of this process in the presence of siliceous compounds was made. The changes in the structure of wool fiber keratin were studied by means of Fourier-transform Infrared and Raman Spectroscopy.

Assessing secondary structure of a dyed wool fibre by means of FTIR and FTR spectroscopies

Abstract The paper describes changes in the structure of a wool fibre dyed with model azo dyes. These were direct dyes, non-genotoxic derivatives of carcinogenic benzidine, synthesized specially for the purpose of the experiment. The non-mutagenic benzidine derivatives were: 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxybenzidine. Using FTIR, changes in secondary structure of fibres were assessed in three measuring ranges: 3600–3000, 1700–1400 and 1000–1300 cm −1 . The dyes were found to distinctively affect wave-number shifts of amide A, amide I bands and in the fingerprint area around 1050 cm −1 . It seems that these three areas are related to the sites in which dyes bind with wool fibre keratin. In FTR spectra, the focus was on assessing the changes of peptide bond configuration in the area of amide I, disulfide area of cystine and the area of the interaction between dyes and wool fibre keratin, i.e. 1250–1600 cm −1 . For analysis, three kinds of materials were selected: (1) raw wool fibres, (2) fibres subjected to deuteration and treated with formic acid, (3) wool fabric. Each of them was dyed with the model azo dyes. The results obtained by both spectroscopies allow for identifying the functional groups responsible for the binding of dyes with keratin fibre.

GPC STUDIES ON BACTERIAL CELLULOSE

The aim of the present study was to examine the effect of time duration of bacterial cellulose (BC) biosynthesis as well as the culture medium composition on molecular parameters of the obtained polymer. It was found that the degree of polymerization of BC increases as the duration of biosynthesis is prolonged up to 6 days. A further prolongation of the process to 28 days lowers the degree of polymerization (DP) value and increases polydispersity. An examination of the effect of culture medium composition on the biosynthesis pointed out that the course of the process is mainly influenced by the chemical nature of the carbon source. The best results for molecular parameters were obtained for a medium containing 4% of glucose.

Static and Fatigue Strength of Linear Textile Products

2Institute of Industrial Engineering, Faculty of Mechanical Engineering and Computer Science, University of Bielsko-Biala, ul. Willowa 2, 43-309 Bielsko-Biała, poland E-mail: skukla@ath.bielsko.pl rdrobina@ath.bielsko.pl Abstract This publication is a review of the work directed or inspired by the late Professor Andrzej Włochowicz in comparison to the current state of knowledge, and developed by his colleagues as an expression of memory and recognition of the contribution that he made to research on the strength of linear textile products. The article describes issues related to the fatigue strength of yarns. An analysis of literature related to the development of research on fatigue strength was carried out, and quantities describing load cycles and selected cases of periodically variable states of loads are presented. The article attempts to systematise certain problems related to the fatigue of textile materials. The body of the article presents the state of knowledge as well as the manner and the methods of assessment of the fatigue strength of textile materials.