MDI and TDI based polyurethanes with tunable mechanical and shape memory performance.

In this work, thermoresponsive shape-memory polyurethane (SMPU) fibers were produced by melt spinning from different SMPU pellets. Afterwards, the knitted fabric samples were prepared by the obtained fibers. Some of the SMPUs used were synthesized previously in our laboratory whereas a commercial one, named DIAPLEX MM4520, was also evaluated in order to carry out comparative studies. All the SMPUs were characterized by different techniques, such as thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis and tensile testing. Moreover, the shape-memory capabilities of the fabrics were measured by thermo-mechanical analysis. The obtained results show that the synthesized SMPUs could be attractive candidates for potential applications such as breathable fabrics or moisture-management textiles.

New polylactide-block-poly(2-cholinium lactate methacrylate) amphiphilic block copolymers were synthesized and characterized. These new block copolymers are composed of chemicals from renewable sources such as lactic acid and cholinium. First a polylactide macro chain transfer agent was synthesized and used to conduct block copolymerization of 2-cholinium lactate methacrylate ionic liquid monomer to form an amphiphilic block copolymer. The polymerizations were successfully conducted through ring-opening polymerization and controlled radical RAFT techniques and confirmed by ¹H NMR and GPC experiments. DLS experiments revealed the formation of self assembled micelles in water and TEM studies confirmed the presence of spherical nanostructures in a dry state having sizes down to 17 nm. To the best of our knowledge this is the first example of an amphiphilic block copolymer having lactic acid units in both copolymer blocks of potential interest in nanomedicine.