# Effect of the Free Radical Initiator on the Production of Castor Oil Maleate Oligomers

## TL;DR

This study explores the use of eco-friendly castor oil maleate oligomers as alternatives to harmful chemical demulsifiers in oil-water separation.

## Contribution

The study identifies the effect of different free radical initiators on the properties of castor oil maleate oligomers.

## Key findings

- DTBP, TBPB, and DCP produced COM oligomers with longer chain lengths compared to persulfate initiators.
- BPO-synthesized COM continued polymerizing during storage, increasing molecular mass and long-chain content.
- Other COMs showed biodegradation, reducing molecular mass and long-chain content over time.

## Abstract

The separation of water from crude oil has long posed
a critical
challenge in the oil industry, where stable water-in-oil emulsions
hinder efficiency and environmental safety. Traditionally, chemical
demulsifiers have been employed in this process. However, most of
these demulsifiers are petroleum-based, toxic, and environmentally
harmful, highlighting the need for sustainable alternatives. Castor
oil maleate (COM) oligomers are suitable biobased demulsifiers for
water-in-oil separation because they are biodegradable, nontoxic,
and environmentally friendly, offering an option toward greener solutions
in oil processing. This study synthesized COM oligomers by reacting
castor oil and maleic anhydride using six distinct initiators: di-tert-butyl peroxide (DTBP), tert-butyl
peroxy benzoate (TBPB), benzoyl peroxide (BPO), dicumyl peroxide (DCP),
potassium persulfate (PSK), and sodium persulfate (PSNa). The findings
revealed that DTBP, TBPB, and DCP produced COM oligomers with a higher
proportion of longer chain lengths compared to persulfate initiators.
COM synthesized using BPO continued polymerizing during storage, increasing
the weight-average molecular mass and a higher content of long-chain-length
oligomers. In contrast, the other COMs demonstrated typical biodegradation
processes, characterized by a reduced weight-average molecular mass
and diminished long-chain-length oligomer content. This study highlights
the potential of COM oligomers to address longstanding challenges
in the oil industry, providing an ecofriendly and efficient alternative
to conventional chemical demulsifiers.