Mixing of Immiscible Polymers in the Solid State

Traditionally, both miscible and immiscible polymers are mixed in solution and melt. In this work, the possibility of mixing immiscible polymers in the solid phase is studied on the example of three pairs of thermodynamically incompatible polymers─ABS/PET, PETG/PBT, PLA/PBT. It is shown that mixing in the solid phase is possible under the conditions of the combined effect of high pressure and shear deformation. High-pressure torsion (HPT) was chosen as the mixing technique. The values of critical accumulated shear strain, which allow the transition from immiscible to miscible blend, were determined. It was found that a higher torsion speed contributes to a faster transition and a higher pressure to a higher degree of convergence of the mixed phases. The homogeneous mixed structure formed is stable above its glass transition or melting temperature after short-term annealing.