Team:TU Darmstadt/Project/PLGA
Contents
PLGA
Abstract
Synthesis of PLGA
Two set ups of PLGA were processed during our time in the laboratory with the method described in the method book.
PLGA (I) with a ratio lactide/glycolide of 75/25
and
PLGA (II) with a ratio lactide/glycolide of 67/33
Results and Discussion
Analysis through GPC
The PLGA (I) set up from 30.07.2018 (Ratio 75/25)
3 mg of the product were solved in 1 ml of the THF/toluene-buffer and measured with a GPC against a polystyrene standard sample. The result shows an average molecule weight of 23,695 g/mol. The expected molecule weight is determined to be 361,669 g/mol. The difference between the expected and the measured result can be explained by the magnetic stirring, which was not able to stir the reaction mixture sufficiently at higher viscosity. Through that the longer polymer chains with a higher density descended, and the lighter monomers with a lower density ascended inside the vessel. This left the polymer chains no possibility to attach the remaining monomers it their ends, while the reaction mixture grew cold and solidified.
The PLGA (II) set up from 24.08.2018 (Ratio 67/33)
3 mg of the product were solved in 1 ml of the THF/toluene-buffer and measured with a GPC against a polystyrene standard sample. The result shows an average molecule weight of 167.9*10^6 g/mol. The expected result is determined to be 2.106*10^6 g/mol. The difference between the expected and the measured result can be explained by humidity, which deactivated part of the Initiator molecules, prohibiting the start of a chain. So the monomers had the chance to spread to other chains and get attached to them, what increased the length of those chains.