Polymeric materials absorb water when exposed to humidity or in contact with aqueous solutions. The polymer and water molecules interact, changing the physicochemical parameters of the material; the most noticeable effect is a decreased glass transition temperature (Tg), known as plasticization. We used microcantilever sensors to measure the Tg versus moisture content in poly(lactic-co-glycolic acid) (PLGA), a biodegradable polymer used in implants and as a drug carrier. We demonstrate a concomitant measurement of the mass absorption and Tg using nanograms of material and an inexpensive setup. The standard deviation of Tg for this system was 0.025 °C, and the variation in Tg with respect to a 1% RH change was clearly resolved. The decrease in the Tg of PLGA was linear (R2 = 0.99) at a rate of 6.03 ± 0.57 °C per mass% of water absorbed. The initial dry Tg of PLGA was extrapolated to 41.24 ± 0.07 °C.
|Number of pages||7|
|Publication status||Published - 2018|
- Thermal analysis
- Poly(lactic-co-glycolic acid)
- Glass transition
Alves, G. M. A., Bose-Goswami, S., Mansano, R. D., & Boisen, A. (2018). Using microcantilever sensors to measure poly(lactic-co-glycolic acid) plasticization by moisture uptake. Polymer Testing, 65, 407-413. https://doi.org/10.1016/j.polymertesting.2017.12.017