The molecular recyclability of poly (ethylene terephthalate) (PET) and three semi-aromatic polyesters poly (phloretic acid) (poly-H), poly (dihydroferulic acid) (poly-G), and poly (dihydrosinapinic acid) (poly-S) is evaluated in this study. PET is an extensively used aromatic polyester, and poly-H, poly-G, and poly-S can be considered semi-aromatic poly (lactic acid) modifications. All these polyesters have been depolymerized at neutral pH and by acid- and base-catalyzed hydrolysis at two temperatures, i.e., 50˚C and 80˚C. Base-catalyzed depolymerization of virgin PET leads to an isolated yield of 38% after 48 hours of reaction at 80˚C. Contrary to these results for PET, almost all the monomers of the semi-aromatic polyesters poly-H, poly-G, and poly-S are recovered with isolated yields larger than 90% at the same temperature after 15 minutes in a facile manner. A shrinking particle model used to determine the global kinetics of the base-catalyzed depolymerization showed that the rate rises with increasing temperature. Using the shrinking particle model, the intrinsic reaction rate constants were determined. It has been demonstrated that the rate coefficients of the depolymerization of the semi-aromatic polyesters poly-H, poly-G, and poly-S are between 2 and 3 orders of magnitude higher than those for PET.
References
[1]
Ruvolo-Filho, A. and Curti, P.S.(2008) PET Recycled and Processed from Flakes with Different Amounts of Water Uptake: Characterization by DSC, TG, and FTIR-ATR. Journal of Materials Science, 43, 1406-1420. https://doi.org/10.1007/s10853-007-2282-6
[2]
Liu, B., Lu, X., Ju, Z., Sun, P., Xin, J., Yao, X., Zhou, Q. and Zhang, S. (2018) Ultrafast Homogeneous Glycolysis of Waste Polyethylene Terephthalate via a Dissolution-Degradation Strategy. Industrial & Engineering Chemistry Research,57, 16239-16245. https://doi.org/10.1021/acs.iecr.8b03854
[3]
Carta, D., Cao, G. and D’Angeli, C. (2003) Chemical Recycling of Poly(Ethylene Terephthalate) (Pet) by Hydrolysis and Glycolysis. Environmental Science and Pollution Research,10, 390-394. https://doi.org/10.1065/espr2001.12.104.8
[4]
Goje, A.S., Thakur, S.A., Diware, V.R., Chauhan, Y.P. and Mishra, S.(2004) Chemical Recycling, Kinetics, and Thermodynamics of Hydrolysis of Poly(Ethylene Terephthalate) Waste with Nonaqueous Potassium Hydroxide Solution. Polymer-Plastics Technology and Engineering,43, 369-388. https://doi.org/10.1081/PPT-120029969
[5]
Paszun, D. and Spychaj, T. (1997) Chemical Recycling of Poly(Ethylene Terephthalate). Industrial & Engineering Chemistry Research,36, 1373-1383. https://doi.org/10.1021/ie960563c
[6]
Karayannidis, G.P. and Achilias, D.S. (2007) Chemical Recycling of Poly(Ethylene Terephthalate). Macromolecular Materials and Engineering,292, 128-146. https://doi.org/10.1002/mame.200600341
[7]
Chilton, T., Burnley, S. and Nesaratnam, S. (2010) A Life Cycle Assessment of the Closed-Loop Recycling and Thermal Recovery of Post-Consumer PET. Resources, Conservation & Recycling,54, 1241-1249. https://doi.org/10.1016/j.resconrec.2010.04.002
[8]
Awaja, F. and Pavel, D. (2005) Recycling of PET. European Polymer Journal,41, 1453-1477. https://doi.org/10.1016/j.eurpolymj.2005.02.005
[9]
Kawai, F., Kawabata, T. and Oda, M. (2019) Current Knowledge on Enzymatic PET Degradation and Its Possible Application to Waste Stream Management and Other Fields. Applied Microbiology and Biotechnology,103, 4253-4268. https://doi.org/10.1007/s00253-019-09717-y
[10]
Shojaei, B., Abtahi, M. and Najafi, M. (2020) Chemical Recycling of PET: A Stepping-Stone toward Sustainability. Polymersfor Advanced Technologies, 31, 2912-2938. https://doi.org/10.1002/pat.5023
[11]
Elias, K.M., Rahman, M.O. and Hossain, H.M.Z. (2023) Predicting Bursting Strength Behavior of Weft Knitted Fabrics Using Various Percentages of Cotton, Polyester, and Spandex Fibers. Journal of Textile Science and Technology, 9, 273-290. https://doi.org/10.4236/jtst.2023.94019
[12]
Van Schijndel, J., Canalle, L.A., Smid, J. and Meuldijk, J. (2016) Conversion of Syringaldehyde to Sinapinic Acid through Knoevenagel-Doebner Condensation. Open Journal of Physical Chemistry, 6, 101-108. https://doi.org/10.4236/ojpc.2016.64010
[13]
Lorenzetti, C., Manaresi, P., Berti, C. and Barbiroli, G.(2006) Chemical Recovery of Useful Chemicals from Polyester (PET) Waste for Resource Conservation: A Survey of State of the Art. Journal of Polymers and the Environment,14, 89-101. https://doi.org/10.1007/s10924-005-8711-1
[14]
Atnurkar, V., Schuster, J. and Pasha Shaik, Y. (2023) Increased Elongation at Breaking Point with Improved Mechanical Characteristics in PLA. Open Journal of Composite Materials, 13, 13-28.
[15]
Zenda, K. and Funazukuri, T. (2008) Depolymerization of Poly(Ethylene Terephthalate) in Dilute Aqueous Ammonia Solution under Hydrothermal Conditions. Journal of Chemical Technology & Biotechnology,83, 1381-1386. https://doi.org/10.1002/jctb.1951
[16]
Zope, V.S. and Mishra, S. (2008) Kinetics of Neutral Hydrolytic Depolymerization of PET (Polyethylene Terephthalate) Waste at Higher Temperature and Autogenous Pressures. Journal of Applied Polymer Science,110, 2179-2183. https://doi.org/10.1002/app.28190
[17]
Yoshioka, T., Motoki, T. and Okuwaki, A. (2001) Kinetics of Hydrolysis of Poly(Ethylene Terephthalate) Powder in Sulfuric Acid by a Modified Shrinking-Core Model. Industrial & Engineering Chemistry Research,40, 75-79. https://doi.org/10.1021/ie000592u
[18]
Yoshioka, T., Okayama, N. and Okuwaki, A. (1998) Kinetics of Hydrolysis of PET Powder in Nitric Acid by a Modified Shrinking-Core Model. Industrial & Engineering Chemistry Research,37, 336-340. https://doi.org/10.1021/ie970459a
[19]
Karayannidis, G.P., Chatziavgoustis, A.P. and Achilias, D.S. (2002) Poly(Ethylene Terephthalate) Recycling and Recovery of Pure Terephthalic Acid by Alkaline Hydrolysis. Advances in Polymer Technology,21, 250-259. https://doi.org/10.1002/adv.10029
[20]
Ruvolo-Filho, A. and Curti, P.S. (2006) Chemical Kinetic Model and Thermodynamic Compensation Effect of Alkaline Hydrolysis of Waste Poly(Ethylene Terephthalate) in Nonaqueous Ethylene Glycol Solution. Industrial & Engineering Chemistry Research,45, 7985-7996. https://doi.org/10.1021/ie060528y
[21]
Tudela, I., Bonete, P., Fullana, A. and Conesa, J.A. (2011) Parameter Sensitivity Study of the Unreacted-Core Shrinking Model: A Computer Activity for Chemical Reaction Engineering Courses. Journal of Chemical Education,88, 56-58. https://doi.org/10.1021/ed100302n
[22]
Van Schijndel, J., Canalle, L.A., Molendijk, D. and Meuldijk, J. (2017) The Green Knoevenagel Condensation: Solvent-Free Condensation of Benzaldehydes. Green Chemistry Letters and Reviews,10, 404-411. https://doi.org/10.1080/17518253.2017.1391881
[23]
Van Schijndel, J., Molendijk, D., Spakman, H., Knaven, E., Canalle, L.A. and Meuldijk, J. (2019) Mechanistic Considerations and Characterization of Ammonia-Based Catalytic Active Intermediates of the Green Knoevenagel Reaction of Various Benzaldehydes. Green Chemistry Letters and Reviews,12, 323-331. https://doi.org/10.1080/17518253.2019.1643931
[24]
Van Schijndel, J., Molendijk, D., Van Beurden, K., Vermeulen, R., Noël, T. and Meuldijk, J. (2020) Repeatable Molecularly Recyclable Semi-Aromatic Polyesters Derived from Lignin. Journal of Polymer Science, 58, 1655-1663. https://doi.org/10.1002/pol.20200088
[25]
Molendijk, D., Van Beurden, K. and Van Schijndel, J. (2020) Designed for Molecular Recycling: A Lignin-Derived Semi-Aromatic Biobased Polymer. Journal of Visualized Experiments, No. 165, e61975. https://doi.org/10.3791/61975
[26]
Naik, S.D. and Doraiswamy, L.K. (1997) Mathematical Modeling of Solid-Liquid Phase-Transfer Catalysis. Chemical Engineering Science,52, 4533-4546. https://doi.org/10.1016/S0009-2509(97)00297-2
[27]
Fogler, H.S. (2017)Essentials of Chemical Reaction Engineering.Pearson Education, London.
[28]
Campanelli, J.R., Kamal, M.R. and Cooper, D.G. (1993) A Kinetic Study of the Hydrolytic Degradation of Polyethylene Terephthalate at High Temperatures. Journal of Applied Polymer Science,48, 443-451. https://doi.org/10.1002/app.1993.070480309
[29]
Chen, J.Y., Ou, C.F., Hu, Y.C. and Lin, C.C. (1991) Depolymerization of Poly(Ethylene Terephthalate) Resin under Pressure. Journal of Applied Polymer Science,42, 1501-1507. https://doi.org/10.1002/app.1991.070420603
[30]
Vaidya, U.R. and Nadkarni, V.M. (1989) Polyester Polyols from Glycolyzed PET Waste: Effect of Glycol Type on Kinetics of Polyesterification. Journal of Applied Polymer Science,38, 1179-1190. https://doi.org/10.1002/app.1989.070380615
[31]
Ramsden, J.M. and Phillips, J.A. (1996) Factors Influencing the Kinetics of the Alkaline Depolymerisation of Poly(Ethylene Terephthalate): The Effect of Solvent. Journal of Chemical Technology & Biotechnology,67, 131-136. https://doi.org/10.1002/(SICI)1097-4660(199610)67:2<131::AID-JCTB538>3.0.CO;2-F
[32]
Wan, B., Kao, C. and Cheng, W. (2001) Kinetics of Depolymerization of Poly(Ethylene Terephthalate) in a Potassium Hydroxide Solution. Industrial & Engineering Chemistry Research,40, 509-514. https://doi.org/10.1021/ie0005304
[33]
Holland, B.J. and Hay, J.N. (2002) The Thermal Degradation of PET and Analogous Polyesters Measured by Thermal Analysis-Fourier Transform Infrared Spectroscopy. Polymer,43, 1835-1847. https://doi.org/10.1016/S0032-3861(01)00775-3
[34]
Lewis, C.L. and Spruiell, J.E. (2006) Crystallization of 2-Methyl-1,3-Propanediol Substituted Poly(Ethylene Terephthalate). I. Thermal Behavior and Isothermal Crystallization. Journal of Applied Polymer Science,100, 2592-2603. https://doi.org/10.1002/app.22786
[35]
Wang, Q., Zhang, F., Qu, D. and Bai, Y. (2019) The Effect of Crystallization Properties Influenced by 2-Methyl-1,3-Propanediol Units on the Optical Properties of Modified Poly(Ethylene Terephthalate). High Performance Polymers,31, 211-219. https://doi.org/10.1177/0954008318758490
[36]
Rahman, S.K., Islam, M., Ratul, S., Dana, N., Musa, S. and Hannan, M. (2018) Properties of Flat-Pressed Wood Plastic Composites as a Function of Particle Size and Mixing Ratio. Journal of Wood Science,64, 279-286. https://doi.org/10.1007/s10086-018-1702-3
[37]
Mishra, S., Goje, A.S. and Zope, V.S. (2003) Chemical Recycling, Kinetics, and Thermodynamics of Poly (Ethylene Terephthalate) (PET) Waste Powder by Nitric Acid Hydrolysis. Polymer Reaction Engineering,11, 79-99. https://doi.org/10.1081/PRE-120018586
