Alkaline hydrolysis of poly (ethylene terephthalate) using 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU)

•DBU demonstrated superior activity for PET hydrolysis relative to sodium hydroxide.•DBU solution exhibit enhanced wettability on PET surface, potentially reducing mass transfer limitations. Advanced polymer recycling methods can address challenges with mechanical recycling caused by contaminated sa...

Full description

Saved in:
Bibliographic Details
Published in:Polymer degradation and stability 2024-07, Vol.225, p.110814, Article 110814
Main Authors: Forouzeshfar, Fahimeh, Abedsoltan, Hossein, Coleman, M.R., Lawrence, Joseph G.
Format: Article
Language:English
Subjects:
Alkaline hydrolysis
Chemical recycling
contact angle
DBU
degradation
ethyl acetate
PET
Polyester
polymers
temperature
Terephthalic acid
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•DBU demonstrated superior activity for PET hydrolysis relative to sodium hydroxide.•DBU solution exhibit enhanced wettability on PET surface, potentially reducing mass transfer limitations. Advanced polymer recycling methods can address challenges with mechanical recycling caused by contaminated samples and mixed plastic wastes. In this work, we report alkaline hydrolysis of poly (ethylene terephthalate) (PET) flakes using a super basic reagent, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) in an aqueous media. The effect of operating conditions including temperature, time, and DBU concentration on the conversion of PET and the yield of terephthalic acid (TPA) was investigated. The relative hydrolysis kinetics were compared for the homogenous reaction of ethyl acetate and heterogenous PET reaction to elucidate the mechanism. While DBU exhibited much higher activity for both systems than NaOH at similar conditions, the increase in rate kinetics was much greater for the PET hydrolysis. This difference in kinetics was attributed to a combination of improved surface wetting of PET by DBU reaction media and the increased activity of the DBU. The hydrolysis of ethyl acetate was studied as a model system to determine the reactant's activity in a homogenous hydrolysis reaction. The effect of surface wetting was studied by conducting contact angle measurements of solutions.
ISSN:0141-3910
1873-2321
DOI:10.1016/j.polymdegradstab.2024.110814