Abstract
Vitrimers constitute a new class of covalent adaptable networks (CANs), in which thermally stimulated associative exchange reactions allow the topological rearrangement of the dynamic network while keeping the number of bonds and the crosslink density constant. The current study proposed a solvent-free method to synthesize vitrimers by reactive melt mixing using a commercial biobased/biodegradable polyester, poly(butylene succinate), PBS. More specifically, a two-step process was followed; the first step involved reactive mixing of PBS with the crosslinker (diglycidyl ether of bisphenol A, DGEBA) and the transesterification catalyst (Zinc(II) acetylacetonate hydrate, Zn(acac)2) in a twin-screw mini-compounder, in order to incorporate the epoxy groups in the polymer backbone. The second step (vitrimerization) comprised a crosslinking process of the homogenous mixtures in a vacuum oven at 170 °C, resulting in the formation of a dynamic crosslinked network with epoxy moieties serving as the crosslinkers. By tuning the crosslinker content (0–10% mol with respect to PBS repeating unit) and the Zinc(II) catalyst to crosslinker ratio (0 to 1), tailor-made vitrimers were prepared with high insolubility and improved melt strength. Moreover, PBS vitrimers could still be reprocessed by compression molding after the crosslinking, which enables the recycling process. This work was made possible by the “Basic Research Programme, NTUA, PEVE 2020 NTUA” [PEVE0050] of the National Technical University of Athens and is gratefully acknowledged.
Supplementary Materials
The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/IOCPS2021-11588/s1.
Author Contributions
Conceptualization, S.V.; methodology, S.V. and CP.; validation, C.P. and D.K.; investigation, C.P.; data curation, C.P. and D.K.; writing—original draft preparation, C.P.; writing—review and editing, S.V. and C.P.; visualization, C.P. and D.K.; supervision, S.V.; project administration, S.V. All authors have read and agreed to the published version of the manuscript.
Funding
This work was funded by the “Basic Research Programme, NTUA, PEVE 2020 NTUA” [PEVE0050] of the National Technical University of Athens and is gratefully acknowledged.
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
The data presented in this study are available upon request from the corresponding author. The data are not publicly available due to restrictions regarding an on-going funded research.
Conflicts of Interest
The authors declare no conflict of interest.
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