Materials that dynamically react to environmental actuations whilst exhibiting various reactions are called smart materials. In recent years, such materials have been widely investigated due to their changes in mechanical, physical and engineering properties resulted from external stimuli. Shape memory materials are those accepting temporary shape and returning to their original shape upon being exposed to environmental actuations such as chemical materials, heat and light. Bio-active shape memory polymers represent several advantages over those lacking shape memory effects and are studied for clinical and medical applications such as shape memory woven estents, scaffolds and surgical sutures. It has been shown in previous studies that polylactic acid (PLA) as a bio-active polymer exhibits favorable shape memory performance, but it has limited applications due to its low mechanical properties such as low toughness and high brittleness resulting in the need for modifications including alloying PLA with other polymers. Thermoplastic polyurethane and ethylene vinyl acetate (EVA), showing both bio-activity and shape memory effect, are considered as polymers to functionalize PLA properties. The goal of the research is fabrication and characterization of bio-degradable-bio- compatible PLA based polymer blends reflecting shape memory properties and the determination of optimized weight fraction of polymers in the eventual blend that possesses targeted performance. To enhance PLA properties, eleven two and three polymer compound systems using the the said polymers blended through an extruder based on the melt mixed process. The optimized weight fraction of alloying polymers was achieved on the basis of the specimens representing best toughness and lowest flexural modulus using mechanical testing including three-point bending, impact, structural testing including scanning electron microscopy and X-ray diffraction, thermal characterization such as differential scanning calorimetric to assess thermal properties of the specimens. To improve the mechanical properties and in particular the toughness and to enhance the affinity of polymers DOA and DCP plasticizers were employed. The studies showed that weight percentages PLA25% TPU60% EVA15% - PLA75% TPU15% EVA10% have the lowest flexural stress and flexural modulus and highest toughness and Elongation at Break. Keywords: Shape Memory Polymers, Polylactic Acid, Thermoplastic Polyurethane, Ethylene Vinyl Acetate, Mechanical Properties, Biodegradable , Biocompatible
