Four blends were prepared by using the solvent casting method: (1) poly(mono‐butyl itaconate)/poly(vinyl chloride) PMBI/PVC; (2) poly(mono‐cyclo hexyl itaconate)/poly(vinyl chloride) PMCHI/PVC; (3) poly(mono‐butyl itaconate)‐poly(dimethyl siloxane)‐poly(mono‐butyl itaconate)/poly(vinyl chloride) PMBI‐PDMS‐PMBI/PVC; and (4) poly(mono‐cyclo hexyl itaconate)‐poly(dimethyl siloxane)‐poly(mono‐cyclo hexyl itaconate) PMCHI‐PDMS‐PMCHI/PVC. These blends were characterized by differential scanning calorimetry (DSC), stress‐strain tests (TENSILON), dielectric thermal analysis (DETA), impedance spectroscopy (IS) and scanning electron microscopy (SEM) analyses. The results showed that the addition of about 1% poly(mono itaconates), or about 1–3% block copolymers containing PDMS blocks have clearly a plasticizing effect on PVC. All characterization methods confirm this conclusion. The addition of higher amounts of homo‐ and block copolymers causes other variations, as a results of several overlapping and synergetic effects.