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Abstract
This thesis deals with the emulsion polymerization of VAc monomer and
BuA monomer using some polymerizable surfactants (surfmers) as will as
classical ones ,in the presence of originally developed acetone sodium
bisulphite & potassium persulphate redox pair initiation system.
In the first part of this study of the work the emulsion polymerization of vinyl
acetate and butyl acrylate using poly ethylene glycol 2, 4, 6 – tris (1-phenyl ethyl)
phenyl ether methacrylate (PEGTPMA) was carried out. The determination of
critical micelle concentration CMC for this surfmer was carried out at 23°C and
70°C and was found to be 4. 7 x 10⎯ ³ mol/l .The order of polymerization reaction
with respect to monomer was found to be 1.02 using vinyl acetate monomer and
2.7 using butyl acrylate. The particle morphology of the produced emulsion was
studied and it was found that increasing surfmer concentration decreases the
particle size Dmax, deviates the particles from spherical morphology.
In the 2nd part of this study an attempt to use a new maleate surfmer to improve
water sensitivity, shear strength of PVAc films and adhesion of PBuA – PVAc
copolymer films and studying all fundamental kinetics was carried out .The course
of emulsion polymerization parameters of vinyl acetate and butyl acrylate using
Bis (2-ethylhexyl) maleate (BEHM) as a novel surfmer was studied in this article.
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The CMC (critical micelle concentration) of the BEHM was found to be
0.008mol/l, (using conductivity measurement) the order of the polymerization
reaction with respect to monomer was found to be 1.3 when using vinyl acetate
monomer and 1 when using butyl acrylate.
The volume average diameter Dv¯ decreases with increasing surfmer concentration
and increases when using butyl acrylate monomer instead of vinyl acetate at the
same conditions of temperature and concentration of monomer and initiator. The
number of polymer particles per unit volume of water Nt was found to increase by
increasing surfmer concentration.
Increasing the surfmer concentration from 14.68 to 29.37 to 44.05 (mol/l),
decreases the surface charge density from 152 to 125 to 107 microcolumb
respectively, for poly (butyl acrylate) emulsion. Poly (butyl acrylate) shows greater
surface charge density and greater stability than PVAc using this surfmer at the
same concentration.
The morphological characteristics of the produced polymers of vinyl acetate and
butyl acrylate using BEHM were measured using transmission electron microscope
and the data’s produced were evaluated using a computerized image analyzer. The
volume average diameter Dv¯, the maximum diameter (Dmax), the number of
polymer particles per unit volume of water (Nt), Dw¯/Dn¯ polydispersity index
and Dcircle/Dmax deviation of spherical morphology were measured and calculated.
The Dv¯ was found to decrease with increasing surfmer concentration also Dv¯
increases when using butyl acrylate monomer instead of vinyl acetate at the same
conditions. The poly (vinyl acetate) shows better morphology with BEHM surfmer
more than poly (butyl acrylate).
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Also a comparison of the different affinities of BuA and VAc to PEGTPMA and
Bis(2-ethylhexyl) Maleate(BEHM)surfmers for the production of stable emulsion
and better morphology were studied . it was found that BuA produces greater
particles size Dv , less polydispersity Dw/Dn , more spherical morphology D circle
/D max and dramatically greater stability as surface charge density (SCD) While
using PEGTPMA surfmer than those while using BEHM also VAc produces
smaller particles size Dv, less spherical morphology D circle /D max and less
stability (SCD) when using PEGTPMA surfmer than those when using BEHM.
Also it can be concluded from these data that PVAc particles are much smaller
than PBuA when we using PEGTPMA as a surfmer , and the particles of PBuA
are more spherical than particles of PVAc .
The 3rd part of this work deals with the industrial application of some of the
prepared lattices, we incorporate the obtained lattices in industrial
applications such as surface coatings or adhesives and compared it with
classical and commercial type , we found that adhesives formulated by
PVAc using BEHM surfmer show greater water resistance than the commercial
and classical type while the adhesion of all of them is nearly the same . also the
paints samples which formulated with poly (VAc and BuA) co-polymer using the
two surfmers PEGTPMA and BEHM shown improving of the adhesion from (B2)
and (B0 )for the commercial and classical types to (B3) and (B2) for the prepared lattices using PEGTPMA and BEHM surfmers respectively. As well as improving of the washability for the paint samples produced using surfmers.
We can conclude that using the surfmers as non immigrating emulsifier, stabilizer, and co-monomer have in general great effect on improving of the properties of the prepared lattices in the paint and adhesives applications.