The invention relates to a multi-layer polymer structure having a polyolefin-based layer, an acrylic-based or other polar polymer layer, and a tie-layer between and adjacent to the polyolefin and acrylic-based layers. Each layer could contain multiple sub-layers. The invention specifically relates to the composition of the tie-layer used to bond the polyolefin-and the polar polymer layers together. The multilayer structure can contain more than three layers, with polar polymer layers on each side of the polyolefin-based layer, and can be made by any method known to the art. The multilayer structure exhibits excellent structural integrity, excellent surface appearance, high impact strength, high scratch resistance, and excellent resistance to UV rays.