a new class of solid solvents selected from adipamides , bisacetamides , biscarbamates , and dibenzamides has been found effective to reduce the melt viscosity of certain block copolymers while not substantially adversely affecting the mechanical properties of the block copolymer when both block copolymer and solid solvent are below their melt temperature . the block copolymers can be polyether - polyurethane block copolymers , polyester - polyurethane block copolymers , polyester - polyether block copolymers , polyamide polyether , or polyamide polyester . the combination is especially useful as an adhesive , as the adhesive component for fabric laminates or as the adhesive for seam sealing tapes .