Stanisław Kuciel

This paper presents an analysis of the properties of biocomposites that were stored for four years in the refrigerator at 6°C and were investigated for detailed information of mechanical properties like tensile strength and bending. The study was based on test results obtained in 2011. Comparison of changes in the structure of composite materials was carried out an analysis of SEM image. Matrix filling materials were made of wood fibres and tuff.

Composites based on a polypropylene matrix with coffee ground powder, wood flour and tuff of a mass weight of 12.5wt% were produced by the method of injection moulding. Tests of tensile and bending strength properties were carried out and Charpy impact was determined at three temperatures: -24°C, 22°C and 80°C. Scanning electron microscopy (SEM) images were taken to assess the effects of reinforcement and homogenization of mixtures and to determine the characteristics of the microstructure. Composites with 12.5wt% coffee ground powder, wood flour and tuff were characterized by an increase the elastic modulus. Tensile strength slightly decreased for composites with ground coffee grains and tuff.

This paper explains why and how to teach engineering students studying structural materials obtained from renewable sources. It describes modern approaches in the education of materials science including focussing on design strategies, sustainability and the use of modern educational tools.

This paper summarises the results of the testing of the mechanical and acoustical behaviour of polyurethane materials with desirable properties. Testing was performed on several samples of materials which were modified during the manufacturing processes. Tests of mechanical parameters included, among other things, the Young modulus and the energy dissipation rate. Tests were conducted on the model 43 MTS Criterion hydraulic testing machine. In the framework of the acoustic research, sound absorption coefficient measurements were conducted. The sound absorption coefficient was measured with the type 4002 Bruel & Kjaer standing wave apparatus. Characteristics of the tested materials are provided.

W artykule zostały opisane kompozyty wytworzone na osnowie całkowicie biopochodnego poliamidu 10.10 wzmocnionego zmielonymi łupinami orzecha włoskiego w ilości masowej 10% oraz 30% jak również kompozyty z dodatkiem 30% masowej ilości włókien szklanych. Zbadano właściwości mechaniczne (wytrzymałość na rozciąganie (σt), moduł sprężystości (Et) oraz moduł sprężystości przy zginaniu (Ef) i naprężenie zginające przy naprężeniu 3,5% (σf)) wytworzonych kompozytów. Dane analizy mechanicznej wykazały, że wytrzymałość na rozciąganie oraz sztywność kompozytów po czterech latach przechowywania znacznie spadły. Jednakże zaobserwowany został niewielki spadek wartości modułu zginania na poziomie 5% w porównaniu do wyników uzyskanych dla kompozytów bezpośrednio po wtrysku. Dodatkowo w celu oceny rozkładu cząstek i adhezji napełniaczy do matrycy wykonano zdjęcia sem. 

This paper presents an investigation in which bio-based polyamide 10.10 was used as a polymer matrix. Composites were reinforced in three different ways including: 10 wt% and 30 wt% of walnut shell flour as well as 30 wt% of glass fibres. The composites were prepared by injection moulding. Mechanical properties (tensile strength (σt), modulus of elasticity (Et) as well as flexural modulus (Ef) and flexural stress at 3.5% strain (σf)) were obtained. The mechanical data of analysis showed that tensile strength and tensile stiffness significantly decreased after four years of storage. Another state was noted for the bending module, where the decrease in value was at a level of 5% compared to results obtained immediately after injection. Additionally, SEM images were taken to assess the distribution of particles and the adhesion of fillers to the matrix.