Polymerization of Lactide to Poly (Lactic Acid): effect of initiators

Plastics are one of the material that responsible for countless aspects of the modern life we enjoy today. It improves our lives due to its flexibility and adaptability that enable them to provide solutions in such a complex world we live in. As the world’s population continue to increase, so does the amount of plastics waste produced by people that could surely lead to massive environmental pollution. To overcome this arising problem, there is a strong need to replace the nonbiodegradable plastics with the biodegradable one. Poly (Lactic Acid) (PLA) is one of the most promising and popular material of biopolymer in the production of biodegradable plastics. The aim of this study were to produce PLA by polymerization of lactide through ring-opening polymerization (ROP) method by using stannous octoate, Sn(Oct)2 as catalyst and to investigate the effect of initiator towards the characteristics of the PLA produced by using UV-Visible Spectrophotometer (UV-Vis) and Fourier Transform Infrared Spectroscopy (FTIR). The experiment was conducted at constant temperature of 120oC for 3 hours in bioreactor by using different types of initiator (1-dodecanol, 1-octanol and methanol). The result obtained from UV-Vis shows that the concentration of PLA increase as the reaction time increase for reaction initiated by methanol and 1-octanol but decrease half-way for 1-dodecanol. The spectrum obtained from FTIR shows that all of the three types of initiator have successfully revealed all the functional group contained in PLA. In overall, methanol is the most effective initiator in polymerization of lactide