Mechanical and morphological studies of porous polylactic acid (PLA): Effect of polydimethylsiloxane (PDMS) incorporation

The aim of this research is to evaluate the presence of sodium chloride (NaCl) and polydimethylsiloxane (PDMS) on the properties of polylactic acid (PLA). The PLA, porous PLA (NPLA) and porous PLA with PDMS (DPLA) was PLA was first dissolved in chloroform under mechanical stirring for 7 minutes before being fabricated using the salt leaching method. The dissolved PLA was then mixed with sodium chloride (NaCl). The chloroform was then evaporated by leaving the PLA and NaCl mixture at room temperature for 24 hours. The NaCl content was then removed by washing the solidified film with tap water. Porous PLA will result from the removal of NaCl content. PLA's mechanical and morphological properties have been studied in relation to its NaCl content. On the other hand, using the same procedure, DPLA is produced by using a solvent immersion method whereas the PDMS and porous PLA are put into a vacuum chamber to reinforce the PDMS into PLA pores. The presence content of NaCl showed for tensile properties decreased by 19 MPa and elongation at break decreased by 43 MPa of the reduction trend while presence of PDMS showed increased trend with 200% for modulus of elasticity than porous PLA but still lower than PLA that 850%. Meanwhile, the presence of NaCl and PDMS was found to increase Young's modulus. At the tensile fractured surface of the neat PLA, the micrograph revealed a smooth surface. However, the effect of the salt leaching method resulted in a porous PLA due to the presence of NaCl, as evidenced by the pores visible in the micrographs. The amount of NaCl in the PLA affects the number of pores and the number of interconnected pores with uniform morphology and evenly distributed pores are affected by the NaCl content.