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Sizing down and functionalizing polylactic acid resin for synthesis of its polyurethane derivatives and their applications |
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| รหัสดีโอไอ | |
| Title | Sizing down and functionalizing polylactic acid resin for synthesis of its polyurethane derivatives and their applications |
| Creator | Oceu Dwi Putri |
| Contributor | Pakorn Opaprakasit, Advisor |
| Publisher | Thammasat University |
| Publication Year | 2568 |
| Keyword | Polylactic acid, Sizing down, Polyurethane, MXene, Wearable strain sensors, Microneedles |
| Abstract | The accumulation of polylactic acid (PLA) waste from single-use products imposes an environmental challenge that necessitates effective valorization strategies. Simultaneously, the biomedical field requires sustainable, multifunctional materials to meet the mechanical and functional requirements of wearable electronics and transdermal drug delivery systems. To address these challenges, this study establishes a chemical recycling platform using microwave-assisted alcohol-acidolysis to convert PLA products into reactive oligomers, simulating an efficient pathway for valorizing PLA waste. The process, when applied to neat PLA resin, is called the sizing down approach. This is an efficient process to synthesize medium-sized PLA oligomers for cosmetic or biomedical applications, with precise control of chemical structures, shortened reaction time, and lower cost compared to a bottom-up synthesis from lactic acid monomer. The resulting chemically sized down oligomers were used to prepare PLA-based polyurethanes (PU) integrated with MXene nanofillers. Through formulation optimization, 1,4-butanediol (BDO) was selected as the chain extender to create a polymer matrix with balanced mechanical strength and flexibility. To demonstrate the potential utilization of these materials, two biomedical applications have been developed. First, flexible conductive films for strain sensing were fabricated using an emulsion-based strategy involving polyvinyl alcohol (PVA). This approach reduced the electrical percolation threshold of MXene distributed in the polymer matrix compared to solution casting methods. The resulting film sensors exhibited high sensitivity, allowing for rapid and precise detection of large-scale human motions and physiological signals, such as finger bending and laryngeal vibrations during speech. Second, dissolvable microneedle (MN) arrays for transdermal drug delivery were engineered by blending the PLA-PU matrix with polyethylene oxide (PEO). This modification improved mechanical integrity, allowing the arrays to withstand insertion forces without fracture. Incorporating minimal MXene loading imparted photothermal responsiveness, generating localized heat under near-infrared (NIR) irradiation to trigger the release of a model drug. The MNs demonstrated cytocompatibility and antioxidant activity in in vitro assays. These findings confirm that the sized-down PLA oligomer feedstocks can be transformed into multifunctional materials for advanced healthcare technologies. |
