Frontal Polymerization of Deep Eutectic Solvents Composed of Acrylic and Methacrylic Acids

Abstract

Frontal polymerization of deep eutectic solvents (DESs) made with acrylic or methacrylic acid as the monomer and hydrogen bond donor was studied. Fronts with acrylic acid and choline chloride propagated more uniformly than with pure acrylic acid, so an exploration into how the DES affected frontal polymerization was performed. The hydrogen bond acceptor of the DES was replaced by several analogs to determine the effect on the DES front behavior. The analogs used were talc, DMSO, lauric acid, and stearic acid, which acted as a heat sink, inert diluent, hydrogen bonding diluent, and inert phase change material, respectively. None of the methacrylic acid-analog systems were able to sustain a front. While the acrylic acid-analog systems did sustain a front (with the exception of stearic acid), none of the fronts replicated the acrylic acid DES behavior. The acrylic acid-talc sample behaved more violently-like pure acrylic acid polymerization-than the acrylic acid DES, and the DMSO and lauric acid samples produced slower fronts than that of the acrylic acid DES. We propose that the reactivity of the acrylic acid and methacrylic acid is enhanced in the DES.

The effect of acrylate functionality on frontal polymerization velocity and temperature

“…Pojman independently “rediscovered” FP in the 1990s while researching methacrylate polymerizations . Since then, research on FP has expanded significantly to include cure‐on‐demand materials, synthesis of gels and gradient materials, epoxide polymerizations, composite materials, and self‐stiffening materials and deep eutectic solvents . Most of the work on FP has involved free‐radical polymerization, although epoxy curing has been considered as well as ring‐opening metathesis polymerization …”

“…[11][12][13][14] Since then, research on FP has expanded significantly to include cure-on-demand materials, 15,16 synthesis of gels [17][18][19][20] and gradient materials, 21,22 epoxide polymerizations, [23][24][25][26] composite materials, [27][28][29][30][31] and self-stiffening materials 32 and deep eutectic solvents. 33,34 Most of the work on FP has involved freeradical polymerization, although epoxy curing 5,23, [35][36][37] has been considered as well as ring-opening metathesis polymerization. [38][39][40][41] Here, we will consider free-radical FP.…”

Low‐Temperature, Rapid Copolymerization of Acrylic Acid and Sodium Acrylate in Water

“…Poly(acrylic acid) (PAA) and related copolymers are widely used in industry for the production of adhesives, superabsorbents, scale inhibitors, and coatings . Despite the breadth of use, the direct synthesis of PAA is not straightforward with the high reactivity of AA in conventional free‐radical polymerization (FRP) leading to high molar masses, broad molar mass distributions, and uncontrolled crosslinking in many cases .…”

Greener, Faster, Stronger: The Benefits of Deep Eutectic Solvents in Polymer and Materials Science

“…The free-radical polymerization of vinyl monomers in DES systems has been relatively well studied, primarily in the context of frontal polymerization [ 60 , 61 , 62 , 63 ]. Mota-Morales et al [ 63 ] first reported polymerizable eutectics based on acrylic (AA) or methacrylic (MAA) acid mixed with ChCl, both of which were liquids at room temperature.…”