Improvements in the Production of Isosorbide Monomethacrylate Using a Biobased Catalyst and Liquid–Liquid Extraction Isolation for Modifications of Oil-Based Resins

The improved production of a polar curable monomer, isosorbide monomethacrylate (MISD), with methacrylic anhydride (MAAH) as an acyl donor, was performed. A sustainable and cheap catalyst, potassium acetate (CH3COOK), was used for a solvent-free synthesis, requiring only the equimolar amount of reagents (no excess). The production included the quantitative separation of the secondary product, methacrylic acid (MAA), preventing the reaction batch from the purification process (neutralization of MAA), and gaining a usable reagent. The synthesis resulted in a sufficient yield of MISD (61.8%) obtained by the liquid–liquid extraction process (LLE), which is a significant improvement in the process, avoiding the flash chromatography step in the isolation of MISD. The purity of synthesized and isolated MISD via the LLE was confirmed by 1H NMR, MS, and FTIR analyses. The thermal analyses, namely, DSC and TGA, were used to characterize the curability and thermal stability of MISD. The activation energy of MISD’s curing was calculated (Ea = 94.6 kJ/mol) along with the heat-resistant index (Ts = 136.8). The polar character of isosorbide monomethacrylate was investigated in a mixture with epoxidized acrylated soybean oil (EASO). It was found that MISD is entirely soluble in EASO and can modify the rheological behavior and surface energy of EASO-based resins. The apparent viscosity of EASO at 30 °C (ηapp = 3413 mPa·s) decreased with the 50% content of MISD significantly (ηapp = 500 mPa·s), and the free surface energy value of EASO (γS = 42.2 mJ/m2) also increased with the 50% content of MISD (γS = 48.7 mJ/m2). The produced MISD can be successfully used as a diluent and the polarity modifier of curable oil-based resins.


MISD miscibility calculation
The theoretical miscibility of MISD was calculated according to Hansen's theory [1].The complete solubility parameter (δ) consists of three particular square summaries: dispersion forces (δ d ), polar forces (δ p ), and hydrogen bonding (δ h ).The equation evaluating the calculation of the complete solubility parameter is formulated as follows: where all parameters defined above posses unit (J/mol).This individual intermolecular forces components' energy values can be found in Hansen's book [1].Once the complete solubility parameters of all compounds are calculated, the "distance" solubility parameter (R a ) can be determined from the followed equation: where the first indexed partial solubility parameter (δd1, δp1, δh1) belongs to the mixed compound (MISD particularly), and the second (δd2, δp2, δh2) describes the intermolecular forces exhibiting the solution media.When the "distance" solubility parameter of each MISD mixture solvent is calculated, the RED value can be reached by the following equation: where R 0 stands for the MISD's complete solubility parameter (δ).The RED value theoretically determines the miscibility of the particular compound (MISD) in any considered solvent.When RED reaches a value below 1, the solvent and compound form an analytical solution; a value above 1 indicates the miscibility inability.All determined, calculated, and summarized parameters describing the solubility of MISD are written in Table S2.S-6

Surface energy modification by MISD
The surface energy of a solid surface (γ S ) (J/m 2 ) can be calculated according to Young's equation ( 4), which defines the solid-liquid and liquid-solid surface free energy (γ SL ) (J/m 2 ) consisting of two energetic summaries: the polarity forces (γ P ) and the dispersion forces (γ d ) (see equation ( 5)).Also, the surface tension of the liquid phase is defined (γ L ) (J/m 2 ).The Young's equation is defined as follows: where θ stands for the contact angle of a particular liquid (°).Used acid-base theory for the calculation of the free surface energy of the solid-state (γ S ) introduces the Lifshitz-van der Waals component (γ LW ), which substitutes the dispersion forces parameter (γ d ).Also, the polar forces parameter (γ P ) is changed, and the Lewis components are defined as acid component (γ + ) and alkali component (γ − ).
The solid-liquid surface energy is modified using the parameters of the converted force as follows: which means that γ SL can be calculated as a geometric average function of force components (for the acid-base theory, the substituted force components).When Young's equation ( 4) is combined with the calculation principle of γ SL , the final equation for the free surface energy can be formed: Since the parameters contact angle (θ), liquid surface tension (γ L ), Lifshitz-van der Waals parameter of the liquid surface tension (γ L LW ), and both Lewis components of liquid (γ L + and γ L − ) can be measured (or calculated), minimal three different liquids need to be measured to calculate the remaining parameters (γ S LW , γ S + and γ S − ).The complete solid-state free surface energy was calculated using the available online calculator from the measured contact angles [4].The principle of the free surface calculation, including the particular parameters' values, was obtained from the literature [3].
Table S3.Surface free energy parameters of control liquid (mJ/m 2 ) [3].The degree of cure (DC) of prepared resins can be calculated by the FT-IR measurement method as follows: where DC is the degree of cure (%); A C=C represents the value of the vinyl C=C stretching signal integral area (-) and A C=O refers to the integral area of C=O stretching signal (-).

Figure S7 .
Figure S7.The graphical interpretation of Arrhenius law applied for MISD containing mixtures.

Figure S8 .
Figure S8.The photographic documentation of the contact angle's measurements of prepared MISDcontaining resins.

Figure S11 .
Figure S11.The degree of cure (DC) of EASO resin containing 30% of MISD measured by FT-IR.

Figure S12 .
Figure S12.The degree of cure (DC) of EASO resin containing 50% of MISD measured by FT-IR.

Table S1 .
The measured and calculated parameters connected to the thermal analysis of MISD.

Table S2 .
The calculated parameters used for the theoretical RED miscibility value determination of MISD.