Poly(styrene-co-butyl acrylate)/Clay Nanocomposite Latexes Synthesized via In Situ Atom Transfer Radical Polymerization in Miniemulsion: Activators Generated by Electron Transfer Approach

Document Type : Research Paper

Authors

Abstract

W
 
 
 
ater born poly(styrene-butyl acrylate)/clay nanocomposite latexes were
synthesized by a novel initiating system of activators generated by
 
electron transfer (AGET) in a system of atom transfer radical polymerization
 
(ATRP). Initially, the clay was swelled in a mixture of styrene, butyl acrylate,
 
and hexadecane. The mixture was then sonicated to obtain a stable miniemulsion. To
 
synthesize poly(styrene-butyl acrylate)/clay nanocomposite latexes, the reducing
 
agent (ascorbic acid) was added dropwise to the reactor (to reduce termination reactions).
 
Particle size and particle size distribution of resulting nanocomposite latexes
 
were determined by dynamic light scattering (DLS). These latex particles were produced
 
with diameters in the size range of 138-171 nm. In addition, the increase in
 
clay content led to increased particles size. Number and weight-average molecular
 
weights of the resultant copolymer nanocomposites and their molecular weight distributions
 
were determined by gel permeation chromatography. The narrow molecular
 
weight distribution of the nanocomposites is an indication of a successful ATRP
 
which was accomplished in miniemulsion formation. Using
 
 
 
 
1
 
H NMR, copolymers
were characterized and the mol ratios of monomers in copolymer composition were
 
calculated. X-Ray diffraction and transmission electron microscopy results showed
 
the mixed intercalated and exfoliated morphologies of nanocomposites in which
 
homogeneous distributions of clay layers in the polymer matrix have been achieved.
 
 
 

Keywords