Bøger af Timo Grüneberg

Wood Polymer Composites are a new group of hybrid materials, which combine the advantagesof synthetic polymers such as polyolefines and natural polymers such as wood; whereas thesynthetic polymer is used as matrix material and the wood as reinforcement material or filler. Asmatrix material, principally every thermoplastic polymer with a processing temperature below200°C can be used due to the temperature sensivity of wood. Wood Polymer Composites areprocessed typically with processing technologies from the plastic industry such as extrusion andinjection molding.The present study was conducted to explore the possibility of wood particle modification withdifferent types of silanes. It was the aim to contribute the silanes as compatibilizers or couplingagent and therefore improve the mechanical properties and the resistance against water. Norwayspruce (Picea abies) as representative wood species was used in three different particle types. Thesize distribution for the wood particles ranges from 70-2500 µm. Four commercial availablesilanes with various functional groups (amino, di-amino, alkyl) were used as modification agents.The concentrations varied between 1.5%, 3.0%, 4.5% and 7.5%. As reference system commonlyused maleated acid anhydride based coupling agents were used. The pre-treated wood particleswere compounded via extrusion with polypropylene and samples were produced via injection andcompression molding. The following properties were tested; tensile, bending, and impactstrength, water uptake (cold and boiling water test), descent rate, weathering tests and durabilitytest against basidiomycetes.