Synthesis and characterization of poly(styrene‐co‐butyl acrylate)/clay nanocomposite latexes in miniemulsion by AGET ATRP

Abstract

Polymer/clay nanocomposite latexes in the form of positively charged nanoparticles were synthesized by a newly developed initiating system, activators generated by electron transfer (AGET), which has been employed in atom transfer radical polymerization (ATRP). These clay‐dispersed latexes were synthesized using AGET ATRP of styrene and butyl acrylate in a miniemulsion system in which, ascorbic acid as a reducing agent was added drop wise to reduce termination reactions. Particle size and particle size distribution of resulted nanocomposite latexes were characterized by dynamic light scattering (DLS). These latexes were in the range of 138 to 171 nm in size. Gel permeation chromatography (GPC) was used to characterize the molecular weight and molecular weight distribution of the resultant copolymer nanocomposites. GPC traces showed that polymers of narrow molecular weight distribution and low Polydispersity Index (PDI) have been synthesized; this clearly shows ATRP reaction is conducted successfully. By increasing nanoclay content, molecular weight of the nanocomposites decreases. The presence of the nanofiller increases the thermal stability of the nanocomposites as investigated by thermogravimetric Analysis (TGA). Glass transition temperature of nanocomposites increases compared with the neat copolymer which was studied by differential scanning calorimetry (DSC). scanning electron microscope (SEM) showed sphere morphology of polymer particles synthesized by miniemulsion polymerization. X‐ray diffraction (XRD) and transmission electron microscopy (TEM) results showed that mixed intercalated and exfoliated morphology is obtained. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

Use of clay-anchored reactive modifier for the synthesis of poly (styrene-co-butyl acrylate)/clay nanocomposite via in situ AGET ATRP

“…Additionally, narrow molecular weight distribution of attached and free copolymer chains indicates that the contribution of termination reactions in copolymerization is negligible. Some of the results obtained from solution copolymerization are in agreement with the results reported in our previous work [22]. But, higher molecular weight and lower PDI values indicate that copolymerization of styrene and butyl acrylate in the presence of PMDETA as the ligand in a solution system which is more successful than miniemulsion system.…”

“…According to the GPC, TGA, and DTG results, there is a balance between the hindrance effect of nanoclay and also low molecular weight of copolymer chains on the final value of the degradation temperature. TGA results are not the same as results that we obtained for copolymerization in miniemulsion system [22]. For copolymerization of styrene and butyl acrylate in miniemulsion, thermal stability of nanocomposites increases with increasing of clay content.…”

“…Also, living radical polymerization is led to polymers with low molecular weights [51,52]. Additionally, molecular weight of polymers synthesized by living radical polymerization is more decreased by the addition of nanoclay [16,21,22]. In this work, GPC results also show that molecular weight of the neat poly (styrene-co-butyl acrylate) decreases by the addition of nanoclay content.…”

“…They obtained random copolymer of styrene and butyl acrylate in the matrix of nanocomposite [21]. In the previous work, we studied synthesis of poly (styrene-co-butyl acrylate) nanocomposite latexes using AGET ATRP in miniemulsion system in the presence of cloisite 30B as a filler [22].Thermal stability and T g of these nanocomposite latexes increased with increasing clay loading. In addition, mixed intercalated and exfoliated morphology of nanoclay in the nanocomposite matrix was obtained for nanocomposite with 0.5 Wt% nanoclay loading.…”

A study on the properties of PMMA/silica nanocomposites prepared via RAFT polymerization

“…Up until now, many polymerization techniques have been adapted for the preparation of polymer/silica nanocomposites, including conventional free radical [18], controlled/living radical polymerization (CLRP) [19][20][21], anionic [22], and cationic [23] polymerizations. To achieve optimum control over the structures of hybrids, CLRP techniques, because of their ability to prepare welldefined, narrow-polydispersity-index (PDI) polymers with versatile architectures, are preferred over the other methods.…”