1. Synthesis of Functionalized Poly(lactic acid) Using 2-Bromo-3-hydroxypropionic Acid
- Author
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Abhishek Banerjee, Xiang Yan, William K. Storms-Miller, Coleen Pugh, and Colin Wright
- Subjects
chemistry.chemical_classification ,Bromine ,Polymers and Plastics ,Organic Chemistry ,Diphenyl ether ,Iodide ,chemistry.chemical_element ,02 engineering and technology ,3-Hydroxypropionic acid ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Lactic acid ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Sodium iodide ,Polymer chemistry ,Materials Chemistry ,Sodium azide ,0210 nano-technology ,Glycolic acid ,Nuclear chemistry - Abstract
Brominated poly(lactic acid) (PLB) and brominated poly(lactic acid-co-glycolic acid) (PLGB) were synthesized by acid-catalyzed melt copolyesterifications of glycolic acid and/or lactic acid with 2-bromo-3-hydroxypropionic acid, which is a brominated constitutional isomer of lactic acid. Molecular weights up to Mn = 104 Da were achieved by adding diphenyl ether to the copolymerizations (100% w/v comonomer concentration) performed at 90–130 °C in vacuo. GPCPSt underestimates the molecular weight of PLB when it contains at least approximately 6 mol % brominated units. The bromine atoms of PLB5050 (MnPSt = 5.32 × 103 Da; absolute Mn ∼ 1.70 × 104 Da) were replaced quantitatively with iodide using sodium iodide in acetone at room temperature, with a modest decrease in the molecular weight (MnPSt = 4.62 × 103 Da). PLB was also reacted with 0.25 equiv of sodium azide in DMF at 0 °C to replace the corresponding amount of bromine atoms in 88% efficiency, again with a slight decrease in the apparent molecular weight...
- Published
- 2016
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