Shape memory polymers were prepared from Surlyn~R 9520, an poly(ethylene-co-methacrylic acid) ionomer and its blends with Zinc Stearate (ZnSt). Surlyn~R 9520 is a semicrystalline ionomer with a broad melting point in the range 60-100 °C, physical cross-links in the ionomer due to interchain ionic interactions provided a "permanent" cross-linked network, while its crystals provided a temporary network. Broad melting point due to the different size of crystals in the ionomer that melt at different temperature allowed demonstrating the tenability of shape memory effect in this ionomer. A separate route of achieving shape memory properties of the samples by blending the ionomer with ZnSt was shown. The strong dipolar interactions between the ionomer and a dispersed phase of crystalline ZnSt can also provide a temporary network. A temporary shape was achieved and fixed by heating and deforming the sample above the melting point (T_m) of the ionomer (or ZnSt) and then cooling down the material below T_m under stress. The original shape was restored by reheating the sample above the T_m of the ionomer (or ZnSt).
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