Effect of Nanoclay on Styrene and Butyl Acrylate AGET ATRP in Miniemulsion: Study of Nucleation Type, Kinetics, and Polymerization Control

Abstract

Poly(styrene‐co‐butyl acrylate)/clay nanocomposites were synthesized in miniemulsion via activators generated by electron transfer (AGET) for atom transfer radical polymerization (ATRP). Optimum amounts of catalyst and reducing agent were chosen by considering a linear increase in ln([M0]/[M]) versus time, narrow molecular distribution, and low polydispersity index (PDI). Critical micelle concentration and cross‐sectional surface area per surfactant head group were determined by surface tension analysis. Calculations show that droplet nucleation is the dominant mechanism of nucleation in a miniemulsion system, and there is no micelle in the system. Gel permeation chromatography was used to characterize molecular weight, PDI, and molecular weight distribution. After determination of appropriate conditions, poly(styrene‐co‐butyl acrylate)/clay nanocomposite latexes were synthesized. Low PDI, narrow molecular weights, and first‐order kinetics of the nanocomposites justify that polymerization is well controlled. Kinetics of polymerization decreases by clay loading. The apparent propagation rate constant (kapp) of polymerization in the case of poly(styrene‐co‐butyl acrylate) is 4.079 × 10−6, which becomes 0.558 × 10−6 in the case of poly(styrene‐co‐butyl acrylate)/clay nanocomposite with 2% nanoclay. A decrease in the polymerization rate is related to the hindrance effect of nanoclay layers on monomer diffusion toward the loci of growing macroradicals.

Synthesis of Nanocapsules and Polymer/Inorganic Nanoparticles Through Controlled Radical Polymerization At and Near Interfaces in Heterogeneous Media

“…thermal stability, even if the clay sheets were in some cases only partially delaminated owing to the lower molar masses of the polymer chains [62]. A deeper kinetic and mechanistic investigation of this AGET ATRP system was later reported [64]. It is worth noting that in all these works, ATRP was used to grow polymer chains in the vicinity of the MMT platelets but not from their surface, since the platelets did not carry any functionalities participating in the ATRP process.…”

Kinetics of MMA Atom Transfer Radical Polymerization Initiated by Reducing Agent in Stirred Batch Emulsion Reactor

“…The apparent propagation rate constant (k app ) of the polymerization can be calculated from the ln([M] 0 /[M]) plot versus time. [13] (…”

“…The apparent propagation rate constant ( k app ) of the polymerization can be calculated from the ln([ M ] 0 /[ M ]) plot versus time. [ 13 ] where [ M ] 0 is the initial monomer concentration, [M] is the monomer concentration at certain time intervals, and t is the reaction time.…”

“…[6] Oh et al [7] conducted a very interesting review of controlled radical polymerization (CRP) techniques in emulsion and dispersion systems.At theoretical level, several studies have reported different mathematical methods to understand the behavior of ATRP in dispersed medium. [10][11][12][13][14][15][16][17][18][19] Assumptions were made in order to simplify the ATRP reaction mechanism. For instance, these ATRP systems were conducted in miniemulsion or dispersion mediums and have polymer particle diameters from 35 to 70 nm with low conversion.…”

Synthesis of poly(2-hydroxyethyl methacrylate-co-acrylic acid)-grafted graphene oxide nanosheets via reversible addition–fragmentation chain transfer polymerization

“…This approach is widely applied for the synthesis of thermo-responsive polymers. 14,15 Although atom transfer radical polymerization (ATRP) is the most investigated controlled radical polymerization technique, 16,17 it is uncontrolled in polymerization of acid-functional monomers such as acrylic acid. 18,19 In most cases, the block copolymers containing PAA block have been prepared via the ATRP of (tert)-butyl acrylate 20 and the subsequent selective deprotection reaction by triuoroacetic acid or trimethylsilyl iodide.…”