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Abstract. In recent decades short fiber reinforced composites have found a widespread application in automotive industry, where the use of petrochemical plastics is more common. The recent development of bio-based plastics offers the opportunity to replace petroleum-based plastics. Owing to this statement, the ability of reinforcing bio-based polyamide 10.10 (PA 1010) by short fibers has been investigated. Traditional fillers, like glass and carbon fibers, have been generally used to achieve high mechanical properties for lightweight structures. A possible combination with manmade cellulose fibers can be an alternative to increase bio-based content in the composite and to save appropriate mechanical properties. Twin screw extrusion and injection molding have been performed to produce granules and test specimens, respectively. Characterization of mechanical properties, such as impact strength, tensile strength and tensile elongation, has been provided. Fiber breakage in glass fiber reinforced composites during the twin screw extrusion process is estimated.

Influence of lubricants such as montan waxes and fatty acid esters, on properties of glass fiber reinforced composites based on polyamide 1010. Composites with 40 % wt. glass fibers were obtained on twin-screw extruder, while the fiber breakage occur. Fiber length distribution were measured. It is shown, that adding of 0.5 % wt. of lubricants increase content of glass fibers longer than 2 critical length and improve mechanical properties.

To expand the range of properties and the range of types of thermoplastic elastomer (TPE), materials based on ternary blends of polypropylene and polar and non-polar rubbers were produced and investigated. To obtain blended and dynamically vulcanised materials, one- and two-stage methods were tested. It was established that the best properties are possessed by composites produced using master batches (rubber mixes) based on a thermoplastic vulcanisate (TPV) rubber phase, and to improve the combination of polymers of different polarity, functionalised additives modifying the polypropylene are necessary. Optical microscopy was used to study the influence of compounding factors (the ratio of components of the polymer phase, the presence or absence of compatibilisers) and technological factors (the production method) on the structure and properties both of blended and of dynamically vulcanised TPEs. A study of the morphology of blended and vulcanised TPEs showed that, in all cases, in the polypropylene, which is the dispersion medium, there are areas rich in rubber to different degrees. Here, fragments of polar rubber are found both in the polypropylene and in zones rich in non-polar rubber, and the range of particle sizes of the disperse phase depends on the production method. The introduction of a compatibiliser leads to a considerable increase in the homogeneity of distribution of the components throughout the material, and to a reduction in the size range of the disperse phase and in the thickness of the polypropylene-rich surface layer of the extrudate (strand). In the surface layer of the strands, anisotropy of the polypropylene fibrils is observed in the direction of extrusion.

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