Abstract
Microwave-assisted ring opening polymerization (ROP) of ε-caprolactone was performed using three different carboxylic acids as initiators. In order to determine the effect of the acidity strength of the initiators on the molecular weight and terminal group functionality, the acids from strongest to weakest, i.e. trifluoro acetic acid, acetic acid, and benzoic acid, were used as initiators. The microwave power was kept at 600 W. The chemical structure and thermal properties of the synthesized low molecular weight PCLs were determined using Fourier Transform Infrared Spectroscopy (FTIR), 1H Nuclear magnetic resonance (1H-NMR) spectroscopy, and differential scanning calorimetry (DSC). The molecular weight of the products was determined and compared using Light Scattering-Gel Permeation Chromatography (LS-GPC) and 1H-NMR spectroscopy. Their spectroscopic analyses showed that microwave-assisted polymerization is a useful technique in synthesizing the low molecular weight PCL without undesirable impurities. Melting points of the synthesized low molecular weight PCLs ranged from 52 °C to 63 °C, as determined by DSC. Their number-average molecular weights (Mn) and polydispersity index (PDI) were between 1.256—1.540 and 1.35—4.90 kDa, respectively. The Mn values obtained from the GPC were consistent with those calculated from 1H-NMR and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) techniques. These findings highlighted the significance of the microwave technique in obtaining low molecular weight PCL for drug delivery formulations.
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References
Tian H, Wu F, Chen P, Peng X (2020) Fang H (2020) Microwave-assisted in situ polymerization of polycaprolactone/boron nitride composites with enhanced thermal conductivity and mechanical properties. Polym Int 69(7):635–643. https://doi.org/10.1002/pi.6000
Yang G, Ma R, Zhang S, Liu Z, Pei D, Jin H et al (2022) Microwave-assisted in situ ring-opening polymerization of epsilon-caprolactone in the presence of modified halloysite nanotubes loaded with stannous chloride. RSC Adv 12(3):1628–1637. https://doi.org/10.1039/d1ra07469e
Ünal S, Doğan O, Aktaş Y (2022) Paclitaxel-Loased Polycaprolactone nanoparticles for lung tumors; Formulation, Comprehensive in vitro characterization and release kinetic studies. J Fac Pharm Ankara 46:1009–1029. https://doi.org/10.33483/jfpau.1161238
Jenkins M, Harrison K (2006) The effect of molecular weight on the crystallization kinetics of polycaprolactone. Polym Adv Technol 17(6):474–478. https://doi.org/10.1002/pat.733
Sun IC, Eun DK, Na JH, Lee S, Kim IJ, Youn IC et al (2009) Heparin-coated gold nanoparticles for liver-specific CT imaging. Cent Eur Hist 15(48):13341–13347. https://doi.org/10.1002/chem.200902344
Camacho KM, Menegatti S, Mitragotri S (2016) Low-molecular-weight polymer–drug conjugates for synergistic anticancer activity of camptothecin and doxorubicin combinations. Nanomedicine (Lond) 11(9):1139–1151. https://doi.org/10.2217/nnm.16.33
Stylianopoulos T (2013) EPR-effect: utilizing size-dependent nanoparticle delivery to solid tumors. Ther Deliv 4(4):421–423. https://doi.org/10.4155/tde.13.8
Witt S, Scheper T, Walter JG (2019) Production of polycaprolactone nanoparticles with hydrodynamic diameters below 100 nm. Eng Life Sci 19(10):658–665. https://doi.org/10.4155/tde.13.8
Storey RF, Sherman JW (2002) Kinetics and mechanism of the stannous octoate-catalyzed bulk polymerization of ε-caprolactone. Macromolecules 35(5):1504–1512. https://doi.org/10.1021/ma010986c
Liao L, Liu L, Zhang C, He F, Zhuo R, Wan K (2002) Microwave‐assisted ring‐opening polymerization of ϵ‐caprolactone. J Polym Sci Part A: Polym Chem 40(11):1749–1755. https://doi.org/10.1002/pola.10256
Limwanich W, Rakbamrung N, Meepowpan P, Funfuenha W, Kongsuk J, Punyodom W (2023) Solvent-free ring-opening polymerization of ε-caprolactone initiated by Mg (II), Sn (II), Zn (II), Al (III), and Sn (IV) derivatives: a comparative study. Reac Kinet Mech Cat 136(1):381–395. https://doi.org/10.1007/s11144-023-02354-7
Funfuenha W, Punyodom W, Meepowpan P, Limwanich W (2023) Microwave-assisted solvent-free ring-opening polymerization of ε-caprolactone initiated by n-butyltin (IV) chlorides. Polym Bull 1–16. https://doi.org/10.1007/s00289-023-04720-w
Hege CS, Schiller SM (2014) Non-toxic catalysts for ring-opening polymerizations of biodegradable polymers at room temperature for biohybrid materials. Green Chem 16(3):1410–1416. https://doi.org/10.1039/C3GC42044B
Tan Y, Cai S, Liao L, Wang Q, Liu L (2009) Microwave-assisted ring-opening polymerization of ɛ-caprolactone in presence of hydrogen phosphonates. Polym J 41(10):849–854. https://doi.org/10.1295/polymj.PJ2009079
Zhang C, Liao L, Gong SS (2007) Recent developments in microwave-assisted polymerization with a focus on ring-opening polymerization. Green Chem 9(4):303–314. https://doi.org/10.1039/B608891K
Babaladimath G, Chapi S (2018) Microwave-assisted synthesis, characterization of electrical conducting and electrochemical xanthan gum-graft-polyaniline. J Mater Sci: Mater Electron 29:11159–11166. https://doi.org/10.1007/s10854-018-9201-2
Persson PV, Schröder J, Wickholm K, Hedenström E, Iversen T (2004) Selective organocatalytic ring-opening polymerization: a versatile route to carbohydrate-functionalized poly (ε-caprolactones). Macromolecules 37(16):5889–5893. https://doi.org/10.1021/ma049562j
Casas J, Persson PV, Iversen T, Córdova A (2004) Direct Organocatalytic Ring-Opening Polymerizations of Lactones. Adv Synth Catal 346(9–10):1087–1089. https://doi.org/10.1002/adsc.200404082
Abdelrazek E, Hezma A, El-Khodary A, Elzayat A (2016) Spectroscopic studies and thermal properties of PCL/PMMA biopolymer blend. Egypt j basic appl sci 3(1):10–15. https://doi.org/10.1016/j.ejbas.2015.06.001
Labet M, Thielemans W (2009) Synthesis of polycaprolactone: a review. Chem Soc Rev 38(12):3484–3504. https://doi.org/10.1039/B820162P
Song Y, Liu L, Weng X, Zhuo R (2003) Acid-initiated polymerization of ε-caprolactone under microwave irradiation and its application in the preparation of drug controlled release system. J Biomater Sci Polym Ed 14(3):241–253. https://doi.org/10.1163/156856203763572699
Yu Z, Liu L, Zhuo R (2003) Microwave‐improved polymerization of ϵ‐caprolactone initiated by carboxylic acids. J Polym Sci Part A: Polym Chem 41(1):13–21. https://doi.org/10.1002/pola.10546
Bixler K, Calhoun G, Scholsky K, Stackman R (1990) Polymerization of epsilon-caprolactone in the presence of carboxylic acids. Polym Prepr 31(2):494–495
Oledzka E, Narine SS (2011) Organic acids catalyzed polymerization of ε-caprolactone: Synthesis and characterization. J Appl Polym Sci 119(4):1873–1882. https://doi.org/10.1002/app.32897
Xu J, Song J, Pispas S, Zhang G (2014) Controlled/living ring‐opening polymerization of ε‐caprolactone with salicylic acid as the organocatalyst. J Polym Sci Part A: Polym Chem 52(8):1185–1192. https://doi.org/10.1002/pola.27104
Chen T, Cai T, Jin Q, Ji J (2015) Design and fabrication of functional polycaprolactone. e-Polymers 15(1):3–13. https://doi.org/10.1515/epoly-2014-0158
Amestoy H, Diego P, Meaurio E, Muñoz J, Sarasua J-R (2021) Crystallization behavior and mechanical properties of poly (ε-caprolactone) reinforced with barium sulfate submicron particles. Materials 14(9):2368. https://doi.org/10.3390/ma14092368
Huang A, Jiang Y, Napiwocki B, Mi H, Peng X, Turng L-S (2017) Fabrication of poly (ε-caprolactone) tissue engineering scaffolds with fibrillated and interconnected pores utilizing microcellular injection molding and polymer leaching. RSC Adv 7(69):43432–442. https://doi.org/10.1039/C7RA06987A
Liu J, Liu L (2004) Ring-opening polymerization of ε-caprolactone initiated by natural amino acids. Macromolecules 37(8):2674–2676. https://doi.org/10.1021/ma0348066
Oledzka E, Sokolowski K, Sobczak M, Kolodziejski W (2011) α-Amino acids as initiators of ε-caprolactone and L. L-lactide polymerization Polym Int 60(5):787–793. https://doi.org/10.1002/pi.3016
Báez JE, Martínez-Richa A, Marcos-Fernandez A (2005) One-step route to α-hydroxyl-ω-(carboxylic acid) polylactones using catalysis by decamolybdate anion. Macromolecules 38(5):1599–1608. https://doi.org/10.1021/ma0491098
Kricheldorf HR, Eggerstedt S (1998) Macrocycles 2. Living macrocyclic polymerization of ε‐caprolactone with 2, 2‐dibutyl‐2‐stanna‐1, 3‐dioxepane as initiator. Macromol Chem Phys 199(2):283–90. First published: 16 December 1998
Huang C-H, Wang F-C, Ko B-T, Yu T-L, Lin C-C (2001) Ring-opening polymerization of ε-caprolactone and L-lactide using aluminum thiolates as initiator. Macromolecules 34(3):356–361. https://doi.org/10.1021/ma0014719
Chapi S (2021) Influence of Co2+ on the structure, conductivity, and electrochemical stability of poly (ethylene oxide)-based solid polymer electrolytes: energy storage devices. J Electron Mater 50(3):1558–1571. https://doi.org/10.1007/s11664-020-08706-6
Hayashi T (1994) Biodegradable polymers for biomedical uses. Prog Polym Sci 19(4):663–702. https://doi.org/10.1016/0079-6700(94)90030-2
Yu Z, Liu L (2004) Effect of microwave energy on chain propagation of poly (ε-caprolactone) in benzoic acid-initiated ring opening polymerization of ε-caprolactone. Eur Polym J 40(9):2213–2220. https://doi.org/10.1016/j.eurpolymj.2004.05.007
Dzienia A, Maksym P, Tarnacka M, Grudzka-Flak I, Golba S, Zięba A et al (2017) High pressure water-initiated ring opening polymerization for the synthesis of well-defined α-hydroxy-ω-(carboxylic acid)polycaprolactones. Green Chem 19(15):3618–3627. https://doi.org/10.1016/j.eurpolymj.2004.05.007
Chen H-L, Li L-J, Ou-Yang W-C, Hwang JC, Wong W-Y (1997) Spherulitic crystallization behavior of poly (ε-caprolactone) with a wide range of molecular weight. Macromolecules 30(6):1718–1722. https://doi.org/10.1021/ma960673v
Tuba F, Olah L, Nagy P (2014) Towards the understanding of the molecular weight dependence of essential work of fracture in semi-crystalline polymers: A study on poly (ε-caprolactone). Express Polym Lett 8(11). https://doi.org/10.3144/expresspolymlett.2014.88
Barbier-Baudry D, Brachais CH, Cretu A, Loupy A, Stuerga D (2002) An Easy Way Toward ε-Caprolactone Macromonomers by Microwave Irradiation Using Early Lanthanide Halides as Catalysts. Macromol Rapid Commun 23(3):200–204
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Ahmadova, I., Tapdiqov, S., Eroglu, M.S. et al. Microwave assisted ring-opening polymerization of Ɛ-caprolactone using organic acids. J Polym Res 30, 291 (2023). https://doi.org/10.1007/s10965-023-03678-7
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DOI: https://doi.org/10.1007/s10965-023-03678-7