Modification of Poly Lactic Acid as a Purposed Renewable Thermoplastic Material for Shape Memory Application

In this study, a temperature sensitive shape memory polymer based on poly lactic acid (PLA) with a switch temperature near human being body temperature has been prepared. PLA is a linear, semi crystalline, biodegradable thermoplastic poly ester which is produced from renewable resources. However, high glass transition temperature (Tg) and the brittleness of PLA limits its wide application especially as an SMP. Therefore, poly ethylene glycol (PEG) has been used to plasticize this polymer. Dynamic mechanical thermal analysis (DMTA) was employed to characterize the glass transition temperature and miscibility of the blend to choose a proper switch temperature for shape memory behavior. Then, an instron tester equipped with a temperature controlled cabin has been used to test the shape memory effects. Shape recovery, shape fixity and rate of recovery have been discussed in detail