engleski

Stability of Wood Plastic Composites Based on High Density Polyethylene

Global ecological concern has promoted an interest in renewable natural materials. One of such materials are for certain wood plastic composites (WPCs) made from wood and some type of polymer material. WPCs are often seen as green composites because the wood is a natural material from the renewable bio-resources and can be successfully recycled together with the polymer matrix. Wood fibers or wood fluor have the potential to act as a biodegradable reinforcing material or filler and they represent the good alternative for the use of glass or carbon fibers and inorganic fillers. Furthermore, wood waste (for example: sawdust) can be also used as a raw material for WPCs, which also makes them ecologically suitable. Nowadays WPCs have widespread use as window profiles, door frames, floors, decks and for some other construction applications. Such big growth in exterior applications of WPCs results in a need to study their stability. In order to predict durability of this material it is especially important to characterize the changes that occur when WPCs are exposed to different weathering conditions: UV light, rain and moisture, low and high temperatures. In this study pine wood flour filled high-density polyethylene (HDPE) composites were manufactured through extrusion. The HDPE/wood fluor ratio in composites was 70/30 while the content of UV stabilizer was from 0.25 to 1.5 phr. In order to simulate outdoor weathering conditions composites were exposed to UV light (vawelength 290 nm) in UV chamber. The samples were studied by thermogravimetric analysis (TGA). The water absorption degree for studied WPC samples was also determined. The results show relatively good resistance of WPCs to outdoor weathering conditions. The best results showed the WPC samples prepared with 0.25 phr of UV stabilizer. It can be concluded that this concentration is the optimal and ensures the most efficient stability of WPCs and delays their degradation.

drvno-plastični kompozit; polietilen; stabilnost

nije evidentirano