Characterisation of PVC/NBR and PVC/ENR50 binary blends and PVC/ENR50/NBR ternary blends by DMA and solid state NMR

The structure and dynamics of the binary blends PVC/NBR and PVC/ENR, and the PVC/ENR/NBR ternary blend were investigated by dynamic mechanical analysis and solid state NMR. Samples were prepared by mechanical blending at 150°C. The effect of the change in the composition of the polymer blends, on the tan δ peak width, the tan δmax and area under the tan δ curve were used to understand the miscibility and damping properties. Solid state 13C-NMR measurements were carried out to determine several relaxation time parameters: rotating frame and laboratory frame proton and carbon relaxation times. Cross-polarisation times and carbon relaxation times were interpreted based on the changes in the molecular motion. Proton relaxation times were interpreted based on the heterogeneity of the matrix. Results confirmed phase separation between 1 and 6 nm length scale.