Shape memory polymer networks based on methacrylated fatty acids

CAPIEL, GUILLERMINA; MARCOVICH, NORMA E.; MOSIEWICKI, MIRNA A.

EUROPEAN POLYMER JOURNAL

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2019 vol. 116 p. 321 - 329

0014-3057

In this study, bio-based materials were prepared from fatty acid precursors and variable amounts of styrene ordivinylbenzene by free-radical polymerization. The obtained materials were highly translucent and resultedinsoluble in common organic and aqueous solvents. They exhibit a complex microstructure due to the formationof highly cross-linked arrangements (micro/nanogels) closed packed into clusters. The bio-polymers preparedwith divinylbenzene (a tetra-functional monomer), due to their excessive cross-linkage, resulted in brittlesamples whose mechanical response could not be obtained. On the other hand, bio-based polymers obtainedfrom styrene (a bi-functional monomer) resulted in materials with a moderate cross-linking density, a sharpglass-rubber transition and acceptable mechanical properties, leading to polymers with interesting shapememory response (switching temperature, fixity and recovery ratios) that could be tailored by changing thecomposition. In these materials it was corroborated that higher (but not excessive) cross-linking density led to agreater shape recovery, since cross-links are the responsible for memorizing the original shape of the material.