Shape-Memory Polymer Nanocomposites of Poly(ε-caprolactone) with the Polystyrene-block-polybutadiene-block-polystyrene-tri-block Copolymer Encapsulated with Metal Oxides.

Abstract

Shape-memory polymer composite (SMPC) blends with thermo-responsive shape memorizing capability have received increasing interest and have been a grooming research area due to their various potential applications. In this work, we report three thermo-responsive SMPCs derived from poly(ε-caprolactone) (PCL) and the polystyrene-block-polybutadiene-block-polystyrene-tri-block copolymer (SBS) encapsulated with CuO, Fe2O3, and CuFe2O4, namely, SMPC–CuO, SMPC–Fe2O3, and SMPC–CuFe2O4, respectively. We have also synthesized the neat shape-memory polymer matrix SMP in the context of the effect of the metal oxide encapsulates on the shape-memory property. Neat SBS rubber and PCL are used as the polymer-elastomer blend matrix to form SMP. The objective of this study is to understand the effect of these three metal oxide nanofillers encapsulated within the SMP matrix and their thermal, mechanical, and shape-memory properties. Morphological, thermal, mechanical, and shape-memory properties of the prepared SMPCs are completely characterized. It is revealed that the addition of nano-metallic-oxide fillers into the polymeric matrix significantly improved the overall properties of SMPCs. The tensile test confirmed that SMPC–CuFe2O4 possesses a high tensile modulus and is found to be very rigid when compared to other SMPCs. The shape fixing property is found in the increasing order as follows: SMPC–CuO > SMPC–Fe2O3 > SMP > SMPC–CuFe2O4. The better thermal, mechanical, and shape-memory performances were shown by the SMPC–Fe2O3 composite, and thus, it can be considered as the better shape-memory polymer nanocomposite among all others. An optimum storage modulus was attained by SMPC–Fe2O3 among the SMPCs. More interestingly, we have developed a microvalve actuator system using SMPC–Fe2O3, which could be useful for promising microsystem applications.