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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.

A three series of terpolymers composed of the blocks PTMO (MPTMO = 1000 g/mol) or DLAol (MDLAol = 540 g/mol), PA12 (MPA12 = 2000 g/mol) and xGT (DPxGT = 2) with various chemical compositions of ester block were obtained. The series differ in the chemical structure of the flexible block and weight content of the soft phase. The effect of the number of carbons dividing the terephthalate groups on the synthesis, structure and properties of these elastomers has been investigated. To confirm assumed chemical structure Carbon-13 (13C NMR) and Proton (1H NMR) Nuclear Magnetic Resonance and Fourier-transform Infrared Spectroscopy (FT-IR) were used. The influence of chemical compositions of ester block on the thermal properties and the phase separation of obtained systems were defined by Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA) and Wide Angle X-ray Scattering (WAXS). The mechanical and elastic properties were evaluated.

Abstract. The elastic modulus and yield stress for polypropylene-based wood-plastic composites are studied as dependent on the type and dosage of wood flour, the type of nanofillers and the method of their incorporation. The effect of nanofillers on the WPC structure is also investigated. It is demonstrated that optical and scanning electron microscopy allows one to make a morphological analysis of the WPC structure.

In the automotive industry, petrochemical plastics are widespread because glass and carbon fiber-reinforced composites consist exclusively of petroleum-based matrix materials. So far, bio-based plastics couldn’t meet the requirement profile due to their high prices, their inappropriate features and the ineligible quality assurance of their synthesis. But the development of new bio-based polyamides opens the opportunity to replace petroleum-based plastics and may initiate the use of bio-based plastic matrices for fiber-reinforced composites for automotive applications.In this study, short fiber-reinforced polyamide 10.10 composites were investigated. Short carbon and glass fibers were used in varying compositions along with different modifiers to optimize the resulting characteristics. Fiber breakage during twin screw extrusion processing was researched and affected by the use of lubricants. The effect of using lubricants was noticed after extrusion. The addition of lubricants caused negative effects on mechanical properties at concentrations higher than 0.5 % wt. Further influences on fiber matrix interactions were investigated by varying the parameters of injection molding and positive effects on tensile properties were recognized. Strengthening effects on resulting composites are discussed in terms of lightweight structure and cost-efficiency.