A Combined Computational and Experimental Study on the Free‐Radical Copolymerization of Styrene and Hydroxyethyl Acrylate

Abstract

Bulk free‐radical copolymerization of styrene and 2‐hydroxyethyl acrylate (HEA) is investigated experimentally at 50 °C using pulsed‐laser polymerization and computationally using ab initio simulations. Arrhenius parameters for HEA chain‐end homopropagation are A = 1.72 × 107 L mol−1 s−1 and Ea = 16.8 kJ mol−1, based on experiments between 20 and 60 °C. Copolymer composition data are well fitted by the terminal model with reactivity ratios rST = 0.44 ± 0.03 and rHEA = 0.18 ± 0.04, but the variation in the propagation rate coefficient with monomer composition is underpredicted. Results are compared with computational predictions assuming the terminal as well as the penultimate unit effect (PUE) model. Intramolecular H‐bonding is shown to have a significant influence on PUE calculations. Discrepancies between computational predictions and experiment are attributed to the influence of intermolecular H‐bonding.

Modeling of Semibatch Solution Radical Copolymerization of Butyl Methacrylate and 2‐Hydroxyethyl Acrylate

“…assumed to be adequately described by the BA coefficients. The changes to propagation kinetics due to H‐bonding and solvent effects present in HEA (co)polymerizations were set as determined by PLP‐SEC studies, with HEA homopropagation kinetics taken from previous investigation that showed a 20% increase in k p over the BA value . HEA/BMA reactivity ratios were determined to be solvent dependent, leading to the two sets of values determined in ketones (set a) and bulk (set b).…”

“…For relative molar masses, polystyrene standards between 870 and 875 000 g mol −1 were used for the calibration of the separation performed by 4 Styragel columns (HR 0.5, 1, 3, 4) maintained at 35 °C, with a sample solution flowrate of 0.3 mL min −1 . Proper transformation of relative molar masses with known Mark–Houwink parameters allows for a suitable comparison and verification between RI and LS results, as reported elsewhere; all MW results presented are from RI detection, due to the superior signal to noise response.…”

“…Future work includes the verification of model predictions in HEA terpolymerizations, as the current model retains the structure required to include ST as a third monomer. The propagation kinetics for ST/HEA in bulk has been studied, such that the only effort required is to conduct the semibatch terpolymerizations at selected conditions to compare to model predictions. As many industrial recipes include more than three components to tune desired coating performance, extension to a BA/BMA/HEA/HEMA model is also possible to meet the need for a flexible prediction tool for both non‐ and functional (meth‐)acrylates.…”

Hydrogen bonding in radical solution copolymerization kinetics of acrylates and methacrylates: a comparison of hydroxy- and methoxy-functionality

“…11,12 We have been systematically studying the influence of the hydroxyl functionality on polymerization kinetics, generally introduced to systems through addition of 2-hydroxyethyl acrylate (HEA) or 2-hydroxyethyl methacrylate (HEMA) monomers, but also possibly through solvent choice. The interaction between the hydroxyl hydrogen and the carbonyl oxygen of the acrylic ester reduces the electron density at the double bond to increase its reactivity, as detected through infrared spectroscopy; 21,22 thus, the kp value for HEMA in bulk 23 is found to be higher than that of butyl methacrylate (BMA) by a factor of 2.5. Hydrogen-bonding also leads to concentration-dependent kp in aqueous systems, 24 as well as a modified relative reactivity in copolymerization, as has been demonstrated for the most prominent systems involving hydroxyl-functional HEA or HEMA 8,22 and carboxyl-functional acrylic acid or methacrylic acid (AA/MAA).…”

Synthesis, properties and thermal stability of water‐soluble poly(potassium 1‐hydroxyacrylate‐co‐styrene) copolymer

“…reversible additionfragmentation chain transfer, pulsed-laser polymerization, radical emulsion polymerization, iodide-mediated radical polymerization, living anionic copolymerization, free radical copolymerization, successive photo-induced charge-transfer polymerization, atom transfer radical polymerization and nitroxide-mediated polymerization. The copolymers containing polystyrene segments have been copolymerized using free radical polymerization with maleic anhydride, 10 divinylbenzene, 11,12 methyl methacrylate, 13,14 hydroxyethyl acrylate, 15 acrylonitrile, 16 butyl acrylate, 17,18 acrylic acid, 19 acrylic acid-styrene sulfonic acid 20 and vinyl acetate. 21 A copolymer of 2,2-dimethyl-5-methylene-1,3-dioxolan-4-one has been synthesized with methyl methacrylate, vinyl acetate and styrene using free radical copolymerization, resulting in higher molecular weight copolymers containing poly(2,2dimethyl-5-methylene-1,3-dioxolan-4-one), poly( -hydroxyacrylic acid) [22][23][24] and its derivative segments.…”