Using microcantilever sensors to measure poly(lactic-co-glycolic acid) plasticization by moisture uptake

Gustavo Marcati A. Alves*, Sanjukta Bose-Goswami, Ronaldo D. Mansano, Anja Boisen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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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.
Original languageEnglish
JournalPolymer Testing
Pages (from-to)407-413
Number of pages7
Publication statusPublished - 2018


  • Microcantilever
  • Thermal analysis
  • Plasticization
  • Poly(lactic-co-glycolic acid)
  • Glass transition

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