Toughening brittle polymers with shape memory polymers

Publication date: 17 January 2018
Source:Polymer, Volume 135
Author(s): Giuliano Siniscalchi Martins, Iaci Miranda Pereira, Rodrigo Lambert Oréfice
Polystyrene (PS) was blended with shape memory polyurethanes (SMPU). Styrene blocks were grafted onto PU chains during SMPU synthesis to yield a modified SMPU with a higher affinity towards PS. Furthermore, blends containing a compatibilizer, poly (styrene-co-maleic anhydride) (SMA), were also prepared by melt mixing the components. The non-compatibilized blends display phase separated structures with PS rich and SMPU rich phases, which were less evident in blends prepared with either the modified SMPU or SMA compatibilizer. The elastic storage modulus of PS was less affected when blended with SMPU in samples containing modified SMPU with styrene grafts. The impact strength of the blends with higher contents of SMPU modified with styrene blocks (25 and 50 wt.%), after shape recovery, was higher than the impact strength of neat PS. The incorporation of shape memory polymers into a brittle polymer matrix is a potential strategy to improve the toughness by external stimuli.

Graphical abstract

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