TY - CHAP
T1 - e-Book of abstracts of ICTAC 2020
AU - Mangialetto, Jessica
AU - Ehrhardt, Dorothee
AU - Cuvellier, Audrey
AU - Verhelle, Robrecht René
AU - Brancart, Joost
AU - Van Assche, Guy
AU - Rahier, Hubert
AU - Van den Brande, Niko
AU - Van Mele, Bruno
PY - 2021/8/31
Y1 - 2021/8/31
N2 - Intrinsic self-healing polymer networks were developed based on dynamic covalent bonding by means of thermoreversible Diels-Alder (DA) cycloadditions. The DA bonds are preferentially broken in case of damage, but also reversibly reform, leading to a repeatable healing cycle and an increased lifetime for many applications, such as sustainable coatings [1], [2]. However, thermo-mechanical robustness is requiring a network in the (partially) vitrified state, with a sufficient-ly high Tg. This work focuses on the effect of vitrification on DA reaction kinetics, using fully reversible model systems of furan and maleimide compounds. In bulk, using (MT)DSC, vitrification is followed through (non-)isothermal heat capacity meas-urements, while non-isothermal microcalorimetry provides heat flow information.These results are used to optimize the parameters of a kinetic model, consid-ering the DA endo−exo stereochemistry. In addition, dynamic rheometry allows the construction of time-temperature-transformation (TTT) and continuous-heating-transformation (CHT) diagrams for both reversible elastomers and thermo-sets [3]. A double asymptotic behavior of the isoconversion lines is revealed, and also two subsequent gelation/degelation events can occur during non-isothermal curing.This bulk study was extended towards thin films through AC chip calorime-try, yielding preliminary results to compare vitrification in bulk and thin layers.This work is the first systematic study of diffusion-controlled reversible DA network formation. The DA reaction was proven to proceed in diffusion-controlled conditions, allowing self-healing in mobility-restricted applications [2], [4].
AB - Intrinsic self-healing polymer networks were developed based on dynamic covalent bonding by means of thermoreversible Diels-Alder (DA) cycloadditions. The DA bonds are preferentially broken in case of damage, but also reversibly reform, leading to a repeatable healing cycle and an increased lifetime for many applications, such as sustainable coatings [1], [2]. However, thermo-mechanical robustness is requiring a network in the (partially) vitrified state, with a sufficient-ly high Tg. This work focuses on the effect of vitrification on DA reaction kinetics, using fully reversible model systems of furan and maleimide compounds. In bulk, using (MT)DSC, vitrification is followed through (non-)isothermal heat capacity meas-urements, while non-isothermal microcalorimetry provides heat flow information.These results are used to optimize the parameters of a kinetic model, consid-ering the DA endo−exo stereochemistry. In addition, dynamic rheometry allows the construction of time-temperature-transformation (TTT) and continuous-heating-transformation (CHT) diagrams for both reversible elastomers and thermo-sets [3]. A double asymptotic behavior of the isoconversion lines is revealed, and also two subsequent gelation/degelation events can occur during non-isothermal curing.This bulk study was extended towards thin films through AC chip calorime-try, yielding preliminary results to compare vitrification in bulk and thin layers.This work is the first systematic study of diffusion-controlled reversible DA network formation. The DA reaction was proven to proceed in diffusion-controlled conditions, allowing self-healing in mobility-restricted applications [2], [4].
M3 - Meeting abstract (Book)
SP - 93
EP - 185
BT - International Congress on Thermal Analysis and Calorimetry 2020
PB - Wydawnictwo Naukowe WNPiD UAM
T2 - ICTAC 2020 <br/>17th International Congress on Thermal Analysis and Calorimetry
Y2 - 29 August 2021 through 2 September 2022
ER -