Lignin role in a complex polyolefin blend

Materials with enhanced surface, thermal properties and degradation characteristics have been obtained by incorporation of the epoxy-modified lignosulfonate (LER) in the binary polyolefin mixture (70 PP/30 PE). The LER content varied from 2.5% to 40%. All properties (mechanical, thermal and surface properties) depend on LER content. The mechanical properties are less influenced for LER content up to 10 wt.% while at high LER amount they decreased. The surface properties show a maximum for 20 wt.% LER and assess that the biocompatibility is improved in 0-20 wt.% LER content range. The behavior of the polyolefin/lignin blends during soil burial test has been monitored. The changes of the polymer blends properties have been investigated before and after soil burial test, by determination of water absorption or weight losses, and by the measurements of the physical-mechanical and surface properties. The physico-mechanical indices for buried samples decrease indicating the initiation of the degradation process. The response of Vicia X Hybrida hort plant to the presence of the blends buried in closed vicinity to its roots has been followed, too, showing a weak negative influence on the physiological processes of the plants. (C) 2004 Published by Elsevier B.V.