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This article describes properties of composites of collagen-hyaluronic acid shaped to layered materials. According to the results, interactions of these two polymers are very strong. The properties can be influenced by chemical crosslinking using glyoxal and starch dialdehyde. The different behavior during enzymatic degradation by collagenase and in swelling experiments is discussed in relation to material composition. The valuable properties of the composites observed in this study show the possibility of their use as biomaterials.

During natural ageing, paper undergoes colour changes and becomes brittle. It is mainly due to the degradation of cellulose, the main component of paper fibres. From the viewpoint of conservation/protection of paper-based information carriers, as well as of the utilisation of secondary fibres, knowledge of the impact of a decrease of the degree of polymerisation (DP) of cellulose on mechanical properties of paper becomes of key importance. In this paper, correlations between the decrease of DP of cellulose and the loss of paper folding endurance (FE) using three model samples (pure cellulose, groundwood pulp paper, and degraded groundwood pulp paper) at accelerated ageing were investigated. The existence of such correlations between DP and FE is supported by experimental results; the correlations are linear for pure cellulose and groundwood pulp paper ageing, while exponential correlation was observed in case of degraded groundwood pulp paper. The results indicate that the rate of paper degradation can be evaluated by means of the rate of glycosidic bonds breaking in cellulosic polymer chains both for cellulose and groundwood pulp paper.

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a Simple, rapid staining analytical methods with visual color assessment are the most used in practice, but they involve problems including subjective error, low accuracy, qualitative results, and the necessity of using many kinds of stains and a great deal of morphology information for correct identification. A method of objective fiber identification using color vectors of a microscan from stained fibre digital photography is described in this report. A model set of cellulose fibres was prepared: groundwood; sulphate pulp; Whatman paper; and rag fibres. The objective micro-colorimetric method, using RGB (red, green, blue) vectors with discriminatory analysis, reduced the number of stains to 1; requires no morphological information; and the discriminatory power (dp,) of this approach is up to 95 to 100% of correctly identified unknown samples with one color vector R or B. A dp value of 100% was achieved when using 2-P or 3-P combinations of R, G, and B.

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