how can i bond polystyrene midsole with rubber sole using polyurethane solvent based adhesive system.
the process is:
clean polystirene with MEK, Apply promoter adhesion (i dont know wich one) and cementing with PU adhesive.
I tried with this adhesion promotors after clean with MEK:
1.chlorinated polyolefines at 6% pbw in MEK/TOL
2.Desmodur L-1260 (isocyanate)at 5% in ETHYL ACETATE
3. Hypalon CP-337 at 6% in MEK/TOL/CICLOHEXANONE
all the results were adhesion fail over the PS. The PU solvent based adhesive did not attach over the surface of the polystyrene