chemicallytechFine Chemical TechnologiesТонкие химические технологии2410-65932686-7575MIREA – Russian Technological University (RTU MIREA).10.32362/2410-6593-2022-17-2-164-171chemicallytech-1824Research ArticleSYNTHESIS AND PROCESSING OF POLYMERS AND POLYMERIC COMPOSITESСИНТЕЗ И ПЕРЕРАБОТКА ПОЛИМЕРОВ И КОМПОЗИТОВ НА ИХ ОСНОВЕObtaining phthalate substituted post-consumer polyethylene terephthalate and its isothermal crystallizationПолучение фталатзамещенного вторичного полиэтилентерефталата и изучение его изотермической кристаллизацииhttps://orcid.org/0000-0002-2611-2217КиршановК. А.KirshanovK. A.

Киршанов Кирилл Андреевич, аспирант, инженер кафедры химии и технологии высокомолекулярных соединений им. С.С. Медведева

119571, Москва, пр-т Вернадского, д. 86

Kirill A. Kirshanov, Postgraduate Student, Engineer, S.S. Medvedev Department of Chemistry and Technology of Macromolecular Compounds

86, Vernadskogo pr., Moscow, 119571

kirill_kirshanov@mail.ruhttps://orcid.org/0000-0003-0843-7082ГервальдА. Ю.GervaldA. Yu.

Гервальд Александр Юрьевич, к.х.н., доцент кафедры химии и технологии высокомолекулярных соединений им. С.С. Медведева

119571, Москва, пр-т Вернадского, д. 86

Alexander Yu. Gervald, Cand. Sci. (Chem.), Associate Professor, S.S. Medvedev Department of Chemistry and Technology of Macromolecular Compounds

86, Vernadskogo pr., Moscow, 119571

gervald@bk.ruhttps://orcid.org/0000-0002-6911-1636ТомсР. В.TomsR. V.

Томс Роман Владимирович, к.х.н., доцент кафедры химии и технологии высокомолекулярных соединений им. С.С. Медведева

119571, Москва, пр-т Вернадского, д. 86

Roman V. Toms, Cand. Sci. (Chem.), Associate Professor, S.S. Medvedev Department of Chemistry and Technology of Macromolecular Compounds

86, Vernadskogo pr., Moscow, 119571

toms.roman@gmail.comhttps://orcid.org/0000-0001-6435-4965ЛобановА. Н.LobanovA. N.

Лобанов Андрей Николаевич, к.х.н., доцент кафедры химии и технологии высокомолекулярных соединений им. С.С. Медведева

119571, Россия, Москва, пр-т Вернадского, д. 86

Andrey N. Lobanov, Cand. Sci. (Chem.), Associate Professor, S.S. Medvedev Department of Chemistry and Technology of Macromolecular Compounds

86, Vernadskogo pr., Moscow, 119571

anlobanov@yandex.ruМИРЭА – Российский технологический университет (Институт тонких химических технологий им. М.В. Ломоносова)РоссияMIREA – Russian Technological University (M.V. Lomonosov Institute of Fine Chemical Technologies)Russian Federation202201062022172164171Copyright © Kirshanov K.A., Gervald A.Y., Toms R.V., Lobanov A.N., 20222022Киршанов К.А., Гервальд А.Ю., Томс Р.В., Лобанов А.Н.Kirshanov K.A., Gervald A.Y., Toms R.V., Lobanov A.N.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.finechem-mirea.ru/jour/article/view/1824Objects

Objects. Due to the polymer waste accumulation, the search for new directions for their utilization is urgent. Chemical recycling methods are of considerable interest, which allow one to obtain the original monomers or change the compositions of the copolymers. From the point of view of building a circular economy, a promising material is polyethylene terephthalate (PET), on the basis of which amorphous copolyesters can be obtained. The study aimed to analyze the simultaneous glycolysis and interchain exchange reactions of PET in the presence of the oligoethylene phthalate modifier with hydroxyl end groups and the study of isothermal crystallization of poly(ethylene phthalate-co-terephthalates) with different phthalate contents obtained in this way.

Methods

Methods. Oligoethylene phthalate is synthesized by polycondensation. Poly(ethylene phthalateco-terephthalates) were obtained by the interaction of post-consumer PET with oligoethylene phthalate. The composition of the oligomer and copolymers was confirmed using Fourier-transform infrared spectroscopy, thermal characteristics and crystallization half-times were determined by differential scanning calorimetry.

Results

Results. In this work, the use of the post-consumer PET chemical recycling process, aimed at obtaining copolyesters under the influence of small modifier amounts was proposed. The process consisted in carrying out the combined interchain exchange and degradation with a complex oligoester different from PET. Poly(ethylene phthalate-co-terephthalate) copolymers were obtained via reaction of post-consumer poly(ethylene terephthalate) flakes and synthesized oligoethylene phthalate resin in the melt phase in the absence of catalyst. The effect of phthalate concentration in polymer on the isothermal crystallization of phthalate substituted poly(ethylene terephthalate) was estimated.

Conclusions

Conclusions. The hypothesis about the possibility of using an oligoester modifier to obtain the PET-based copolymer at the high rate and without reducing the molecular weight to values characteristic of a monomer or oligomer has been confirmed. The process can be used to obtain random copolyesters based on post-consumer PET. The phthalate unit concentration increase is followed by decrease in the glass transition temperature, temperature and heat of fusion, and increase in crystallization half-times. Phthalate has a better ability to retard PET crystallization than 2-methyl-1,3-propanediol or furandicarboxylic acid, but is inferior to some of the other modifiers known.

Цели

Цели. Накопление полимерных отходов в последнее время обуславливает поиск новых подходов к их утилизации. Значительный интерес представляют химические способы вторичной переработки, которые позволяют получить исходные мономеры или изменить составы сополимеров. С точки зрения построения экономики замкнутого цикла перспективным материалом является полиэтилентерефталат (ПЭТ), из которого в процессе химического рециклинга получают аморфные сополиэфиры. Работа посвящена исследованию одновременного протекания реакций гликолиза и межцепного обмена ПЭТ в присутствии модификатора олигоэтиленфталата с гидроксильными концевыми группами и изучению изотермической кристаллизации поли(этилен фталат-со-терефталатов) с разным содержанием фталата, полученных таким способом.

Методы

Методы. Олигоэтиленфталат синтезирован поликонденсацией. Поли(этилен фталат-со-терефталаты) получены взаимодействием вторичного ПЭТ с олигоэтиленфталатом. Состав олигомера и сополимеров был подтвержден с использованием ИК-Фурье спектроскопии, термические характеристики и полупериоды кристаллизации определяли методом дифференциальной сканирующей калориметрии.

Результаты

Результаты. Разработан процесс получения сополиэфиров, основанный на химическом рециклинге вторичного ПЭТ под действием малых количеств модификатора. Отличительной особенностью процесса является одновременное протекание реакций межцепного обмена и деструкции сложным олигоэфиром, отличным по природе от ПЭТ. Реакцией в расплаве вторичного ПЭТ и синтезированного олигоэтиленфталата в отсутствие катализатора были получены поли(этилен фталат-со-терефталаты). Изучено влияние концентрации фталата в полимере на температуру стеклования, температуру и теплоту плавления, изотермическую кристаллизацию фталатзамещенного ПЭТ.

Выводы

Выводы. Подтверждена гипотеза о возможности использовани олигоэфирного модификатора для получения сополимера на основе ПЭТ с высокой скоростью и без снижения молекулярной массы до значений, характерных для мономера или олигомера. Процесс может быть использован для получения статистических сополиэфиров на основе вторичного ПЭТ. С увеличением концентрации звеньев фталата происходит снижение температуры стеклования, температуры и теплоты плавления, увеличение полупериодов кристаллизации. Фталат обладает лучшей способностью замедлять кристаллизацию ПЭТ, чем 2-метил-1,3-пропандиол или фурандикарбоновая кислота, но уступает некоторым другим известным модификаторам.

полиэтилентерефталатПЭТПЭТФсополиэфирхимический рециклинг ПЭТгликолиздеструкциямежцепной обменизотермическая кристаллизацияpolyethylene terephthalatePETcopolyesterchemical recycling of PETglycolysisdegradationinterchain exchangeisothermal crystallizationReferencesScheirs J., Long T.E. Modern Polyesters: Chemistry and Technology of Polyesters and Copolyesters. London: John Wiley & Sons, Ltd; 2003. 750 p. https://doi.org/10.1002/0470090685Scheirs J., Long T.E. Modern Polyesters: Chemistry and Technology of Polyesters and Copolyesters. London: John Wiley & Sons, Ltd; 2003. 750 p. https://doi.org/10.1002/0470090685George N., Kurian T. Recent Developments in the Chemical Recycling of Postconsumer Poly(ethylene terephthalate) Waste. Ind. Eng. Chem. Res. 2014;53(37):14185–14198. https://doi.org/10.1021/ie501995mGeorge N., Kurian T. Recent Developments in the Chemical Recycling of Postconsumer Poly(ethylene terephthalate) Waste. Ind. Eng. Chem. Res. 2014;53(37):14185–14198. https://doi.org/10.1021/ie501995mKhoonkari M., Haghighi A.H., Sefidbakht Y., Shekoohi K., Ghaderian A. Chemical Recycling of PET Wastes with Different Catalysts. Int. J. Polym. Sci. 2015;1–11. https://doi.org/10.1155/2015/124524Khoonkari M., Haghighi A.H., Sefidbakht Y., Shekoohi K., Ghaderian A. Chemical Recycling of PET Wastes with Different Catalysts. Int. J. Polym. Sci. 2015;1–11. https://doi.org/10.1155/2015/124524Raheem A.B., Noor Z.Z., Hassan A., Hamid M.K.A., Samsudin S.A., Sabeen A.H. Current developments in chemical recycling of post-consumer polyethylene terephthalate wastes for new materials production: A review. J. Clean. Prod. 2019;225:1052–1064. https://doi.org/10.1016/j.jclepro.2019.04.019Raheem A.B., Noor Z.Z., Hassan A., Hamid M.K.A., Samsudin S.A., Sabeen A.H. Current developments in chemical recycling of post-consumer polyethylene terephthalate wastes for new materials production: A review. J. Clean. Prod. 2019;225:1052–1064. https://doi.org/10.1016/j.jclepro.2019.04.019Liu B., Lu X., Ju Z., Sun P., Xin J., Yao X., Zhou Q., Zhang S. Ultrafast homogeneous glycolysis of waste polyethylene terephthalate via a dissolution-degradation strategy. Ind. Eng. Chem. Res. 2018;57(48):16239–16245. https://doi.org/10.1021/acs.iecr.8b03854Liu B., Lu X., Ju Z., Sun P., Xin J., Yao X., Zhou Q., Zhang S. Ultrafast homogeneous glycolysis of waste polyethylene terephthalate via a dissolution-degradation strategy. Ind. Eng. Chem. Res. 2018;57(48):16239–16245. https://doi.org/10.1021/acs.iecr.8b03854Киршанов К.А., Гервальд А.Ю., Томс Р.В. Получение сложных олигоэфиров направленной гликолитической деструкцией отходов полиэтилентерефталата. Пластические массы. 2020;1(11–12):51–53. https://doi.org/10.35164/0554-2901-2020-11-12-51-53Kirshanov K.A., Gerval’d A.Yu., Toms R.V. Оbtaining oligoesters by directed glycolytic destruction of polyethylene terephthalate waste. Plasticheskie massy. 2020;1(11–12):51–53 (in Russ.). https://doi.org/10.35164/0554-2901-2020-11-12-51-53Киршанов К.А., Томс Р.В. Исследование гликолиза полиэтилентерефталата смесью бис(2-гидроксиэтил) терефталата и его олигомеров. Пластические массы. 2021;1(3–4):50–52. https://doi.org/10.35164/0554-2901-2021-3-4-50-52Kirshanov K.A., Toms R.V. Study of polyethylene terephthalate glycolysis with a mixture of bis(2-hydroxyethyl) terephthalate and its oligomers. Plasticheskie massy. 2021;1(3–4):50–52 (in Russ.). https://doi.org/10.35164/0554-2901-2021-3-4-50-52El Mejjatti A., Harit T., Riahi A., Khiari R., Bouabdallah I., Malek F. Chemical recycling of poly(ethylene terephthalate). Application to the synthesis of multiblock copolyesters. eXPRESS Polymer Letters. 2014;8(8):544–553. https://doi.org/10.3144/expresspolymlett.2014.58El Mejjatti A., Harit T., Riahi A., Khiari R., Bouabdallah I., Malek F. Chemical recycling of poly(ethylene terephthalate). Application to the synthesis of multiblock copolyesters. eXPRESS Polymer Letters. 2014;8(8):544–553. https://doi.org/10.3144/expresspolymlett.2014.58Борисов В.А. Некоторые способы рециклинга вторичного полиэтилентерефталата. Известия Кабардино-Балкарского Государственного Университета. 2013;3(5):18–23.Borisov V.A. Some ways of recycling the secondary polyethylene terephthalate. Izvestiya Kabardino-Balkarskogo Gosudarstvennogo Universiteta = Proceeding of the Kabardino-Balkarian State University. 2013;3(5):18–23 (in Russ.).Colomines G., Robin J.-J., Tersac G. Study of the glycolysis of PET by oligoesters. Polymer. 2005;46(10):3230–3247. https://doi.org/10.1016/j.polymer.2005.02.047Colomines G., Robin J.-J., Tersac G. Study of the glycolysis of PET by oligoesters. Polymer. 2005;46(10):3230–3247. https://doi.org/10.1016/j.polymer.2005.02.047Litmanovich A.D., Plate N.A., Kudryavtsev Y.V. Reactions in polymer blends: interchain effects and theoretical problems. Progress in Polymer Science. 2002;27:915–970. https://doi.org/10.1016/S0079-6700(02)00003-5Litmanovich A.D., Plate N.A., Kudryavtsev Y.V. Reactions in polymer blends: interchain effects and theoretical problems. Progress in Polymer Science. 2002;27:915–970. https://doi.org/10.1016/S0079-6700(02)00003-5Krentsel’ L.B., Makarova V.V., Kudryavtsev Ya.V., Govorun E.N., Litmanovich A.D., Markova G.D., Vasnev V.A., Kulichikhin V.G. Interchain exchange and interdiffusion in blends of poly(ethylene terephthalate) and poly(ethylene naphthalate). Polym. Sci. Ser. A. 2009;51(11–12):1241–1248. https://doi.org/10.1134/S0965545X09110091Krentsel’ L.B., Makarova V.V., Kudryavtsev Ya.V., Govorun E.N., Litmanovich A.D., Markova G.D., Vasnev V.A., Kulichikhin V.G. Interchain exchange and interdiffusion in blends of poly(ethylene terephthalate) and poly(ethylene naphthalate). Polym. Sci. Ser. A. 2009;51(11–12):1241–1248. https://doi.org/10.1134/S0965545X09110091Heidarzadeh N., Rafizadeh M., Taromi F.A., del Valle L.J., Franco L., Puiggali J. Biodegradability and biocompatibility of copoly(butylene sebacate-coterephthalate) s. Polym. Degrad. Stab. 2017;135:18–30. https://doi.org/10.1016/j.polymdegradstab.2016.11.013Heidarzadeh N., Rafizadeh M., Taromi F.A., del Valle L.J., Franco L., Puiggali J. Biodegradability and biocompatibility of copoly(butylene sebacate-coterephthalate) s. Polym. Degrad. Stab. 2017;135:18–30. https://doi.org/10.1016/j.polymdegradstab.2016.11.013Collins S., Peace S.K., Richards R.W., MacDonald W.A., Mills P., King S.M. Transesterification in poly(ethylene terephthalate). Molecular weight and end group effects. Macromolecules. 2000;33(8):2981–2988. https://doi.org/10.1021/ma991637Collins S., Peace S.K., Richards R.W., MacDonald W.A., Mills P., King S.M. Transesterification in poly(ethylene terephthalate). Molecular weight and end group effects. Macromolecules. 2000;33(8):2981–2988. https://doi.org/10.1021/ma991637Turner S.R. Development of amorphous copolyesters based on 1,4-cyclohexanedimethanol. J. Polym. Sci.: A: Polym. Chem. 2004;42(23):5847–5852. https://doi.org/10.1002/pola.20460Turner S.R. Development of amorphous copolyesters based on 1,4-cyclohexanedimethanol. J. Polym. Sci.: A: Polym. Chem. 2004;42(23):5847–5852. https://doi.org/10.1002/pola.20460Shirali H., Rafizadeh M., Taromi F.A. Synthesis and characterization of amorphous and impermeable poly(ethylene-co-1,4-cyclohexylenedimethylene terephthalate)/ organoclay nanocomposite via in situ polymerization. J. Compos. Mater. 2014;48(3):301–315. https://doi.org/10.1177/0021998312471566Shirali H., Rafizadeh M., Taromi F.A. Synthesis and characterization of amorphous and impermeable poly(ethylene-co-1,4-cyclohexylenedimethylene terephthalate)/ organoclay nanocomposite via in situ polymerization. J. Compos. Mater. 2014;48(3):301–315. https://doi.org/10.1177/0021998312471566Granado A., Iturriza L., Eguiazabal J.I. Structure and mechanical properties of blends of an amorphous polyamide and an amorphous copolyester. J. Appl. Polym. Sci. 2014;131(18):40785. https://doi.org/10.1002/app.40785Granado A., Iturriza L., Eguiazabal J.I. Structure and mechanical properties of blends of an amorphous polyamide and an amorphous copolyester. J. Appl. Polym. Sci. 2014;131(18):40785. https://doi.org/10.1002/app.40785Tingting C., Guodong J., Jun Z. Isothermal crystallization behavior and crystal structure of poly(ethyleneterephthalate-co-1,4-cyclohexylenedimethyleneterephthalate) (P(ET/CT)) copolyesters. Cryst. Res. Technol. 2014;49(4):232–243. https://doi.org/10.1002/crat.201300369Tingting C., Guodong J., Jun Z. Isothermal crystallization behavior and crystal structure of poly(ethyleneterephthalate-co-1,4-cyclohexylenedimethyleneterephthalate) (P(ET/CT)) copolyesters. Cryst. Res. Technol. 2014;49(4):232–243. https://doi.org/10.1002/crat.201300369Tingting C., Guodong J., Jun Z. Alkali resistance of poly(ethylene terephthalate) (PET) and poly(ethylene glycolco-1,4-cyclohexanedimethanol terephthalate) (PETG) copolyesters: the role of composition. Polym. Degrad. Stab. 2015;120:232–243. https://doi.org/10.1016/j.polymdegradstab.2015.07.008Tingting C., Guodong J., Jun Z. Alkali resistance of poly(ethylene terephthalate) (PET) and poly(ethylene glycolco-1,4-cyclohexanedimethanol terephthalate) (PETG) copolyesters: the role of composition. Polym. Degrad. Stab. 2015;120:232–243. https://doi.org/10.1016/j.polymdegradstab.2015.07.008Seung W.H., Hee S.M., Jong S.B., Eui S.Y., Seung S.I. Synthesis and crystallization behaviors of modified PET copolymers. Fibers Polym. 2012;1(2):76–82. https://doi.org/10.1007/BF02875189Seung W.H., Hee S.M., Jong S.B., Eui S.Y., Seung S.I. Synthesis and crystallization behaviors of modified PET copolymers. Fibers Polym. 2012;1(2):76–82. https://doi.org/10.1007/BF02875189Nagahata R., Sugiyama J., Velmathi S., Nakao Y., Goto M., Takeuchi K. Synthesis of poly(ethylene terephthalateco-isophthalate) by copolymerization of ethylene isophthalate cyclic dimer and bis(2-hydroxyethyl) terephthalate. Polym. J. 2004;36(6):483–488. https://doi.org/10.1295/polymj.36.483Nagahata R., Sugiyama J., Velmathi S., Nakao Y., Goto M., Takeuchi K. Synthesis of poly(ethylene terephthalateco-isophthalate) by copolymerization of ethylene isophthalate cyclic dimer and bis(2-hydroxyethyl) terephthalate. Polym. J. 2004;36(6):483–488. https://doi.org/10.1295/polymj.36.483Liyuan S., Yajie Z., Jinggang W., Fei L., Zhen J., Xiaoqing L., Jin Z. 2,5-Furandicarboxylic acid as a sustainable alternative to isophthalic acid for synthesis of amorphous poly(ethylene terephthalate) copolyester with enhanced performance. J. Appl. Polym. Sci. 2018;47186. https://doi.org/10.1002/app.47186Liyuan S., Yajie Z., Jinggang W., Fei L., Zhen J., Xiaoqing L., Jin Z. 2,5-Furandicarboxylic acid as a sustainable alternative to isophthalic acid for synthesis of amorphous poly(ethylene terephthalate) copolyester with enhanced performance. J. Appl. Polym. Sci. 2018;47186. https://doi.org/10.1002/app.47186Kim J.H., Lee S.Y., Park J.H., Lyoo W.S., Noh S.K. Kinetics of polycondensation and copolycondensation of bis(3-hydroxypropyl terephthalate) and bis(2-hydroxyethyl terephthalate). J. Appl. Polym. Sci. 2000;77(3):693–698. https://doi.org/10.1002/(SICI)1097-4628(20000718)77:3<693::AID-APP24>3.0.CO;2-QKim J.H., Lee S.Y., Park J.H., Lyoo W.S., Noh S.K. Kinetics of polycondensation and copolycondensation of bis(3-hydroxypropyl terephthalate) and bis(2-hydroxyethyl terephthalate). J. Appl. Polym. Sci. 2000;77(3):693–698. https://doi.org/10.1002/(SICI)1097-4628(20000718)77:3<693::AID-APP24>3.0.CO;2-QLewis C.L., Spruiell J.E. Crystallization of 2-methyl- 1,3-propanediol substituted poly(ethylene terephthalate). I. Thermal behavior and isothermal crystallization. J. Appl. Polym. Sci. 2006;100(4):2592–2603. https://doi.org/10.1002/app.22786Lewis C.L., Spruiell J.E. Crystallization of 2-methyl- 1,3-propanediol substituted poly(ethylene terephthalate). I. Thermal behavior and isothermal crystallization. J. Appl. Polym. Sci. 2006;100(4):2592–2603. https://doi.org/10.1002/app.22786Tsai Y., Fan C-H., Wu J-H. Synthesis, microstructures and properties of amorphous poly(ethylene terephthalate-cotricyclodecanedimethylene terephthalate). J. Polym. Res. 2016;23(3):23–42. https://doi.org/10.1007/s10965-016-0933-5Tsai Y., Fan C-H., Wu J-H. Synthesis, microstructures and properties of amorphous poly(ethylene terephthalate-cotricyclodecanedimethylene terephthalate). J. Polym. Res. 2016;23(3):23–42. https://doi.org/10.1007/s10965-016-0933-5Legrand S., Jacquel N., Amedro H., Saint-Loup R., Pascault J.-P., Rousseau A., Fenouillot F. Synthesis and properties of poly(1,4-cyclohexanedimethylene-coisosorbide terephthalate), a biobased copolyester with high performances. Eur. Polym. J. 2019;115:22–29. https://doi.org/10.1016/j.eurpolymj.2019.03.018Legrand S., Jacquel N., Amedro H., Saint-Loup R., Pascault J.-P., Rousseau A., Fenouillot F. Synthesis and properties of poly(1,4-cyclohexanedimethylene-coisosorbide terephthalate), a biobased copolyester with high performances. Eur. Polym. J. 2019;115:22–29. https://doi.org/10.1016/j.eurpolymj.2019.03.018Wang B., Zhang Y., Song P., Guo Z., Cheng J., Fang Z. Synthesis, characterization, and properties of degradable poly(l-lactic acid)/poly(butylene terephthalate) copolyesters containing 1,4-cyclohexanedimethanol. J. Appl. Polym. Sci. 2011;120(5):2985–2995. https://doi.org/10.1002/app.33373Wang B., Zhang Y., Song P., Guo Z., Cheng J., Fang Z. Synthesis, characterization, and properties of degradable poly(l-lactic acid)/poly(butylene terephthalate) copolyesters containing 1,4-cyclohexanedimethanol. J. Appl. Polym. Sci. 2011;120(5):2985–2995. https://doi.org/10.1002/app.33373Lee B., Lee J.W., Lee S.W., Yoon J., Ree M. Synthesis and non-isothermal crystallization behavior of poly(ethylene phthalate-co-terephthalate)s. Polym. Eng. Sci. 2004;44(9):1682–1691. https://doi.org/10.1002/pen.20168Lee B., Lee J.W., Lee S.W., Yoon J., Ree M. Synthesis and non-isothermal crystallization behavior of poly(ethylene phthalate-co-terephthalate)s. Polym. Eng. Sci. 2004;44(9):1682–1691. https://doi.org/10.1002/pen.20168Connor D.M., Allen S.D., Collard D.M., Liotta C.L., Schiraldi D.A. Effect of comonomers on the rate of crystallization of pet: U-turn comonomers. J. Appl. Polym. Sci. 2001;81(7):1675–1682. https://doi.org/10.1002/app.1599Connor D.M., Allen S.D., Collard D.M., Liotta C.L., Schiraldi D.A. Effect of comonomers on the rate of crystallization of pet: U-turn comonomers. J. Appl. Polym. Sci. 2001;81(7):1675–1682. https://doi.org/10.1002/app.1599Du B., Yang R., Xie X. Investigation of hydrolysis in poly(ethylene terephthalate) by FTIR-ATR. Chin. J. Polym. Sci. 2014;32(2):230–235. https://doi.org/10.1007/s10118-014-1372-6Du B., Yang R., Xie X. Investigation of hydrolysis in poly(ethylene terephthalate) by FTIR-ATR. Chin. J. Polym. Sci. 2014;32(2):230–235. https://doi.org/10.1007/s10118-014-1372-6Descamps N., Fernandez F., Heijboer P., Saint-Loup R., Jacquel N. Isothermal crystallization kinetics of poly(ethylene terephthalate) copolymerized with various amounts of isosorbide. Appl. Sci. 2020;10(3):1046. https://doi.org/10.3390/app10031046Descamps N., Fernandez F., Heijboer P., Saint-Loup R., Jacquel N. Isothermal crystallization kinetics of poly(ethylene terephthalate) copolymerized with various amounts of isosorbide. Appl. Sci. 2020;10(3):1046. https://doi.org/10.3390/app10031046Terzopoulou Z., Papadopoulos L., Zamboulis A., Papageorgiou D.G., Papageorgiou G.Z., Bikiaris D.N. Tuning the properties of furandicarboxylic acid-based polyesters with copolymerization: a review. Polymers. 2020;12(6):1209. https://doi.org/10.3390/polym12061209Terzopoulou Z., Papadopoulos L., Zamboulis A., Papageorgiou D.G., Papageorgiou G.Z., Bikiaris D.N. Tuning the properties of furandicarboxylic acid-based polyesters with copolymerization: a review. Polymers. 2020;12(6):1209. https://doi.org/10.3390/polym12061209

The authors declare that there are no conflicts of interest present.