# Synthesis of Glycerin Carbonate by an Environmentally Friendly Novel Catalytic Membrane of Poly(vinyl alcohol)/Deep Eutectic Solvent

## TL;DR

Researchers developed a green catalytic membrane to efficiently produce glycerin carbonate from glycerin and dimethyl carbonate.

## Contribution

The novel PVA/DES catalytic membrane is introduced for the first time in glycerin carbonate synthesis.

## Key findings

- A maximum glycerin carbonate yield of 65.4% was achieved under optimized reaction conditions.
- The membrane reactor increased glycerin carbonate yield to 74.0% in 3 hours.
- The PVA/DES catalytic membrane is identified as a suitable and eco-friendly material for glycerin carbonate synthesis.

## Abstract

A novel and eco-friendly catalytic material, poly­(vinyl
alcohol)-supported
deep eutectic solvent (PVA/DES) catalytic membrane, was prepared and
used to produce value-added glycerin carbonate (GLC) from glycerin
and dimethyl carbonate (DMC) for the first time. The heterogeneous
form of catalytic membrane was prepared in the form of a film using
PVA polymer as a support and an environmentally friendly DES, consisting
of potassium hydroxide (KOH) and poly­(ethylene glycol) (PEG), as the
catalyst. Fourier-transform infrared (FTIR) and thermogravimetric
analysis (TGA) characterizations were performed to assess the functional
groups and thermal stability of the PVA/DES catalytic membrane. Moreover,
the change in the chemical structure of the catalytic membrane after
the reaction was investigated by FTIR. The interaction between the
catalytic membrane and glycerin is described by contact angle measurements.
The relationship between reaction time, amount of catalyst, temperature,
DMC/glycerin initial molar ratio, and reaction yield in batch reactions
with PVA/DES catalytic membrane was discussed. The maximum GLC yield
of 65.4% was obtained at 33% catalyst amount, 85 °C, DMC/glycerin:
3:1, and a reaction time of 4 h. The additional membrane reactor study
increased the 3 h GLC yield to 74.0%. Furthermore, the effects of
catalyst amount and DMC/Glycerin ratio on the reaction yield in the
Response Surface Methodology (RSM) study with a central composite
design were compared. It was found that the PVA/DES catalytic membrane
is a suitable and green catalytic material for GLC synthesis from
DMC.