Modification of lignin–polyethylene blends with high lignin content using ethylene–vinylacetate copolymer as modifier

Blending of polyethylene with lignin in concentrations > 20 wt % yielded blends with relatively low mechanical properties. A new method, based on modification of polyethylene with ethylene–vinylacetate (EVA) copolymer, was developed for the preparation of polyethylene blends containing about 30 wt % lignin with acceptable strength properties. The addition of 10 wt % EVA caused an increase of tensile strength about twice and elongation at break about 13 times compared to those of the corresponding nonmodified samples. The optimization of lignin–polyethylene–EVA blend composition was based on a regression equation, which was obtained as output from an experimental design. The prepared composite material with 33.6 wt % lignin showed acceptable processing and mechanical properties. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1855–1860, 2004