Effect of Fatty Acid Polyunsaturation on Synthesis and Properties of Emulsion Polymers Based on Plant Oil-Based Acrylic Monomers.

Vasylyna Kirianchuk,Ananiy Kohut,Andriy Voronov,Yehor Polunin,Zoriana Demchuk,Stanislav Voronov

doi:10.3390/molecules27030932

Abstract

This study demonstrated that polymerization behavior of plant oil-based acrylic monomers (POBMs) synthesized in one-step transesterification reaction from naturally rich in oleic acid olive, canola, and high-oleic soybean oils is associated with a varying mass fraction of polyunsaturated fatty acid fragments (linoleic (C18:2) and linolenic (C18:3) acid esters) in plant oil. Using miniemulsion polymerization, a range of stable copolymer latexes was synthesized from 60 wt.% of each POBM and styrene to determine the impact of POBM chemical composition (polyunsaturation) on thermal and mechanical properties of the resulted polymeric materials. The unique composition of each plant oil serves as an experimental tool to determine the effect of polyunsaturated fatty acid fragments on POBM polymerization behavior and thermomechanical properties of crosslinked films made from POBM-based latexes. The obtained results show that increasing polyunsaturation in the copolymers results in an enhanced crosslink density of the latex polymer network which essentially impacts the mechanical properties of the films (both Young’s modulus and toughness). Maximum toughness was observed for crosslinked latex films made from 50 wt.% of each POBM in the monomer feed.

Highlights

Due to the depletion of fossil fuels and the environmental deterioration, there is a surge in research to find alternative feedstocks for polymer synthesis
The latter observation shows that the molecular weight of latexes made from a high amount of plant oil-based acrylic monomers (POBMs) can be controlled by varying the polyunsaturation in the plant oil chosen for monomer synthesis
When POBM fragments are incorporated into latex copolymers at a higher extent (60 wt.%), the crosslinking density becomes excessive, causing loss of the resulted polymer network flexibility and stiffening the resulted films made from copolymers based on both high-oleic soybean oil-based monomer (HOSBM) and canola oil-based monomer (CLM)

Summary

Introduction

Due to the depletion of fossil fuels and the environmental deterioration, there is a surge in research to find alternative feedstocks for polymer synthesis. The obtained results (Table 3) indicate that, as expected, the number average molecular weight (Mn) of the latex copolymers decreases with an increasing mass fraction of polyunsaturated fatty acid fragments in the resulted materials (WPUF) The latter observation shows that the molecular weight of latexes made from a high amount of POBMs can be controlled by varying the polyunsaturation in the plant oil chosen for monomer synthesis. Taking into account all the observations (Table 3), our step in this study was to consider the effect of polyunsaturated—C18:2 linoleic acid- and C18: 3 linolenic acid-based fractions of each POBM on the properties of highly biobased latexes and their crosslinked films’ mechanical performance For this purpose, a range of stable latexes with a varying biobased content was synthesized in miniemulsion from OVM, HOSBM, and CLM copolymerized with styrene in the presence of 4% surfactant (SDS, based on oil ph.). The latter characteristics can be utilized to distinguish the effects of polyunsaturated fragments on the thermal and mechanical

50 OVM 50 HOSBM

POBMs and POBM-Based Polymer Characterization

Latex Synthesis

Plant Oil-Based Latex Characterization

Findings

Conclusions