PLP/SEC/NMR Study of Free Radical Copolymerization of Styrene and Glycidyl Methacrylate

Abstract

Free radical copolymerization of glycidyl methacrylate (GMA) and styrene (ST) is systematically investigated using low conversion pulsed laser polymerization (PLP) experiments. It is shown that GMA, like other methacrylate monomers, undergoes significant depropagation at elevated temperatures. While ST/GMA copolymer composition is well represented by the terminal model, the copolymer-averaged propagation rate coefficient for the system is not; the latter quantity is represented using the implicit penultimate unit model. The PLP data are used to estimate GMA depropagation kinetics as well as ST/GMA monomer (r ST ) 0.31 and r GMA ) 0.51) and radical (s ST ) 0.28 and s GMA ) 1.05) reactivity ratios, which show no significant variation in the 50-140 °C temperature range examined. The GMA/ST copolymerization behavior is compared to that of butyl methacrylate (BMA) with ST; GMA monomer is more active toward styrene radicals than BMA, and a GMA unit in the penultimate position of styrene radicals reduces copolymerization propagation to a greater extent.

Exploring the Full Potential of Reversible Deactivation Radical Polymerization Using Pareto-Optimal Fronts

“…During the last two decades, reversible deactivation radical polymerization (RDRP), which is also known as controlled radical polymerization (CRP), has shown to overcome disadvantages of conventional free radical polymerization (FRP), which allows mostly the synthesis of commodity polymer products [1][2][3][4][5][6][7], unless expensive functional monomers are used [8,9]. Under well-defined conditions, RDRP techniques are characterized by the establishment of a dynamic pseudo-equilibrium between propagating and dormant species, allowing the controlled incorporation of monomer units per activation-growth-deactivation cycle.…”

Free‐Radical Acrylic Polymerization Kinetics at Elevated Temperatures

“…DG 0 ÀRT c k p =k dp RT c lnM RT lnM eq (4) Of the monomers considered in this treatment, the methacrylates exhibit the greatest propensity to depropagate, as typical values of DH for methacrylates are in the range of -50 to -60 kJ mol -1 [8][9][10][11]. Since the reversibility of propagation was first reported by Ivin and Dainton [12], methacrylate depropagation behavior has been studied by Ivin et al [13][14][15][16], Bywater [17], and others [18][19][20].…”

“…The decrease was represented by a linear relation f m = A+Bf p , where A and B are two constants deduced using thermodynamic equations in terms of free energy change and interaction parameters between polymer, solvent, and monomer [28,29]. Grady et al [31] [10,11]. Thus, the effect of depropagation on polymerization rate and polymer MW is important under high-temperature conditions, especially for the starved-feed (and thus low monomer concentration) semibatch process often employed [1,31].…”

“…(7) and (8). This treatment has been extended by Li et al [42] to include the situation where both monomers depropagate, and also for the case where the penultimate unit has an effect on chain-growth kinetics, i.e., if the terminal model does not provide an adequate description of k p,cop [11,40]. Methacrylate depropagation has been included in the detailed kinetic models developed to describe semibatch copolymerization of ST/BMA [35] and ST/DMA [3,34] systems, as well as in the kinetic model for styrene/acrylate/methacrylate terpolymerization [1].…”

“…Secondary mechanisms important in the high-temperature free radical polymerization of methacrylate/acrylate/styrene systems. where [1,11,40]. Although a wide range of methacrylates and acrylates are used in industry, their copolymerization behavior [110] and the side reactions discussed in this article are not strongly affected by the identity of the ester group.…”