Copolymer styrene and vinylpyrrolidone were prepared using different techniques. The emulsion polymerization technique was chosen as it gives the highest molecular weight with polymer particles in the nanorange. The polymer nanocomposites were prepared using Pickering emulsion polymerization stabilized by adding inorganic nanosized particles. Ag nanometal and nanometal oxides of CuO, ZnO and AgO were added into the copolymer for enhancing its thermal stability and electrical conductivity. The nanocomposite chemical structure was confirmed by using FTIR, 1HNMR spectroscopy and TEM. Transmission electron microscopy, TEM photos show that the copolymer particles are almost in the nanoscale region. The thermal stability (TGA) of styrene-co-vinylpyrrolidone in the presence of the nanometal and nanometal oxides was slightly increased. The electrical conductivity of these nanocomposites using dc at different temperatures was measured. The data reveal that the nanocomposites are enhanced by adding the nanometal and nanometal oxides.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3556

Abdelfatah, Badawi

Azza, Mazrouaa

Maher, Elsabee

Mohamed, Fathy

Nahla, Mansour

SocioEconomic Challenges Journal (Sumy State University)

JOURNAL OF NANO- AND ELECTRONIC PHYSICS ЖУРНАЛ НАНО- ТА ЕЛЕКТРОННОЇ ФІЗИКИ 
Vol. 5 No 4, 04063(5pp) (2013) Том 5 № 4, 04063(5cc) (2013) 
 
 
2077-6772/2013/5(4)04063(5) 04063-1  2013 Sumy State University 
Preparation of Emulsion Polymerization from Styrene Vinylpyrrolidone and Studying their 
Thermal Stability and Electrical Conductivity 
 
Azza Mazrouaa1,*, Abdelfatah Badawi1, Nahla Mansour1, Mohamed Fathy1, Maher Elsabee2 
 
1 Petrochemical Department, Egyptian Petroleum Research Institute (EPRI), 1 Ahmed El-Zomor St., Nasr City, 
11727 Cairo, Egypt 
2 Department of Chemistry, Faculty of Science, Cairo University, 12613 Giza, Egypt 
 
(Received 24 August 2013; published online 31 January 2014) 
 
Copolymer styrene and vinylpyrrolidone were prepared using different techniques. The emulsion 
polymerization technique was chosen as it gives the highest molecular weight with polymer particles in the 
nanorange. The polymer nanocomposites were prepared using Pickering emulsion polymerization stabi-
lized by adding inorganic nanosized particles. Ag nanometal and nanometal oxides of CuO, ZnO and AgO 
were added into the copolymer for enhancing its thermal stability and electrical conductivity. The nano-
composite chemical structure was confirmed by using FTIR, 1HNMR spectroscopy and TEM. Transmission 
electron microscopy, TEM photos show that the copolymer particles are almost in the nanoscale region. 
The thermal stability (TGA) of styrene-co-vinylpyrrolidone in the presence of the nanometal and nanomet-
al oxides was slightly increased. The electrical conductivity of these nanocomposites using dc at different 
temperatures was measured. The data reveal that the nanocomposites are enhanced by adding the nano-
metal and nanometal oxides. 
 
Keywords: Styrene, Vinyl pyrrolidone, Copolymer, Emulsion polymerization, Nanometal oxides, 
FTIR, 1HNMR spectroscopy, TEM and electrical conductivity. 
 
 PACS numbers: 47.57.jb, 72.80.Le 
 
 
                                                                
* azza_mazroua2005@yahoo.com 
1. INTRODUCTION 
 
Polycarbonate, polymethyl methacrylate, polysty-
rene, polyvinyl butyral, polyvinyl carbazole, and vari-
ous copolymers can act as polymer stabilizers of nano-
particles. Polymers and copolymers of  
N-vinylpyrrolidone, ethylene oxide, etc., are used [1-5]. 
Notably, polyaniline (PANI), polypyrrole (PPy), poly-
thiophene (PT), polyacetylene (PA) poly(p-
phenylenevinylene (PPV) and their derivatives have 
attracted the interest of researchers in multidiscipli-
nary fields primarily for their unique structural and 
electronic properties. Nanometer-sized particles have 
been made from different organic-inorganic particles 
which impart the composite materials improved prop-
erties [6]. Different particles have been used to prepare 
polymer / inorganic particle nanocomposites, including: 
metals (Al, Fe, Au, Ag, etc.), metal oxides (ZnO, Al2O3, 
CaCO3, TiO2 etc.), nanometal oxide (SiO2) [7], and  
other (SiC). The selection of nanoparticles depends on 
the desired thermal, mechanical, and electrical proper-
ties of the nanocomposites [8, 9]. 
Polypyrrole (PPy) nanoparticles in polystyrene (PS) 
matrix were synthesized by emulsion polymerization 
using ferric sulfate, sodium dodecyl sulfate, and n-amyl 
alcohol as an oxidant, emulsifier and dopant, and co-
emulsifier, respectively. The content of PPy nanoparti-
cles in the composites varied from 14.11 to 34.63 wt %, 
as calculated from elemental analysis. Field Emission 
Scanning Electron Microscopy (SEM) images showed 
spherical nanopartciles of PPy with diameters of 30-
74 nm well dispersed in PS matrix. It was found that 
the thermal stability and electrical conductivity of 
PS / PPy composites increase with increasing content of 
PPy nanoparticles [10]. Highly monodisperse polysty-
rene (PS) nanospheres were fabricated by surfactant-
free emulsion polymerization in water using styrene, 
2,2’-azobis (2-methyl propionamidine) dihydrochloride 
(AIBA), and poly(vinyl pyrrolidone) (PVP) [11]. PS nan-
ospheres were produced by surfactant-free emulsion 
polymerization in water using styrene, 2,2’-azobis (2-
methyl propionamidine) dihydrochloride (AIBA), and 
poly(vinyl pyrrolidone)(PVP). 
 
2. EXPERIMENTAL PART 
 
2.1 Chemicals 
 
N-vinylpyrrolidone (VP), styrene (ST) monomers so-
dium hydrogen sulfate (NaHSO4), potassium persulfate 
(K2S2O8), sodium lauryl sulfate (SLS) silver nanopow-
der ( 100 nm, 99 % metal basis), copper (II) oxide na-
nopowder ( 50 nm), silver oxide (reagent plus, 99 %), 
zinc phthalocyanine (ZnPc) and copper phthalocyanine 
(CuPc) were all supplied from Aldrich. 
 
2.2 Equipment 
 
FT-IR: Was performed using Perkin-Elmer 1650 
FTIR spectrophotometer using KBr technique. 
TGA: All TGA spectra were recorded under a nitro-
gen atmosphere up to 800 °C using programmed rate of 
10 °C/min. SDT Q600 V20-5 builds 15 with size of  
5-1590 mg, Ramp method and range from 10 to 1200 C. 
TEM: Jeol-JSM Japan Model 2100. 
Electrical conductivity. The samples were pressed 
into pellets of 1.33 cm diameter and 1 mm thickness in 
ahydraulic press (Kimaya Engineers; India; Model WT-
324) at five metric ton pressure. The conductivity 
measurements were carried out by four-probe tech-
nique recorded by Keithley electrometer type 6517 A. 
 AZZA MAZROUAA, ABDELFATAH BADAWI, NAHLA MANSOUR, ET AL. J. NANO- ELECTRON. PHYS. 5, 04063 (2013) 
 
 
04063-2 
The pellet used in this measurement is placed between 
two copper electrodes; which were connected to the two 
terminal of Keithley electrometer. 
 
2.3 Emulsion Copolymerization 
 
The reaction was carried out in a flask connected to 
a condenser system. The reaction mixture was 
1/3 molar ratio between (St) and (VP), 18 g water, 0.5 % 
initiator (2/1 ratio between NaHSO4 and K2S2O8) and 
4 % surfactant (SLS). The reaction was carried out at 
100 C for 3 hours. The resultant solution was poured 
in large excess of methanol to destroy the emulsion and  
was slowly heated to form large particles that can be 
filtered. The precipitated polymer was vacuum-filtered 
and washed several times with methanol and water 
then dried at 65 C for 10 hours till constant weight. 
 
2.4 Preparation of Copolymer St-VP / Inorganic 
Nanoparticles 
 
The polymer nanocomposites were prepared using 
Pickering emulsion polymerization stabilized by adding 
inorganic nanosized particles. 
The polymer nanocomposites were prepared using 
Pickering polymerization in which the emulsion is addi-
tionally stabilized by adding inorganic nanosized parti-
cles. Theoretical and experimental researches of Picker-
ing emulsion polymerization were developed by He [12-
14] and Blinks [15, 16]. When the size of inorganic parti-
cle is reduced to nanoscale, they are able to assemble on 
the surfaces of monomer droplets to form a stable dis-
persion. After polymerization inorganic / polymer compo-
site particles can be obtained. Many kinds of inorganic 
nanoparticles have been reported to be utilized in Picker-
ing emulsion polymerization, including magnetite, cobalt 
ferrite [17, 18], cerium dioxide [19], titania [20], or silica 
[21, 22]. Pickering emulsion polymerization provides 
simple and effective way to prepare inorganic/organic 
composite materials. 
Monomers of (St) and (VP) were added at ratio 1/3 
with 18 g water, 0.5 % initiator (2/1 ratio between  
NaHSO4 and K2S2O8) and 4 % surfactant. The reaction 
was carried out at 100 C for 3 hours. After 1 hour 3 % 
of metal nanoparticles was added in-situ to the reaction 
medium. The resultant solution was poured in large 
excess of methanol to destroy the emulsion and slowly 
heated to form large particles that can be filtered. The 
precipitated polymer was vacuum-filtered and washed 
several times with methanol and water then dried at 
65oC for 10 hours till constant weight. 
 
3. RESULT AND DISCUSSION 
 
3.1 Characterization 
 
GPC: Styrene vinylpyrrolidone copolymers are good 
film forming materials. They also can be a good base to 
accommodate different nanoparticles of metals or their 
oxides. The molecular weight determination of the re-
sulting copolymers using micro emulsion method gave 
the highest molecular weight. Molecular weight deter-
mination was done by gel permeation chromatography 
(GPC) by using CRYETTEA instrument- automatic 
cryoscope. The method is based on Avogadro-Gerhadt 
law chromatography (GPC) in THF. It was found that 
the MW  64581 at 50 %. 
The structures of the copolymer were confirmed by 
FTIR (Fig. 1), 1H NMR (Fig. 2). 
FTIR: The peaks at 1672, 1386 and 1424 cm – 1 are 
due to CO, C-N-C imide and C-N stretching from the 
NVP unit. St shows a peak at 3076 cm – 1 (aromatic C-H 
stretch), 2954 and 2879 cm – 1 (asymmetricand symmet-
ric C-H stretch respectively), 1561 (aromatic CC 
stretch) and 696 cm – 1 (aromatic C-H out of plane bend-
ing) [23]. 
1 HNMR: Methine proton in N-vinyl pyrrolidone 
resonates at   3.60, while methylene protons , ,  
to the carbonylgroup of NVP resonate between 
  1.18-2.28 ppm. In styrene, the aromatic protons are 
assigned at   7.24 ppm and methine protons appear 
at   2.79 ppm [24, 25]. By using the data from 
1 HNMR spectrum, we calculated the percentages of 
each monomer in the synthesized copolymer which was 
70 % St and 30 % VP. This high ratio of styrene, though 
its low feed ratio (3 : 1 N-vinyl pyrrolidone to styrene), 
due to its high reactivity ratio which is 15.509 for sty-
rene and 0.102 for N-vinyl pyrrolidone [26]. 
 
 
 
Fig. 1 – FT-IR for styrene co N-Vinyl pyrrolidone 
 
 
 
Fig. 2 – NMR for styrene co N-vinyl pyrrolidone 
 
3.2 Size Analysis 
 
Particle size of the prepared copolymer was 
measured using Malvern zeta-sizer in ethanol after 
mixing with ethylene glycol. The measurement was 
performed in triplicate and the median was 79.25 nm 
as shown in (Fig. 3). 
 
3.3 Thermal Gravimetric Analysis (TGA) 
 
The thermal stability of polymer composites is gen-
erally estimated from the weight loss upon heating 
which results in the formation of volatile products. The 
change in  sample weight as a function of temperature 
was observed. 
 PREPARATION OF EMULSION POLIMERIZATION FROM STYRENE VINYLPYRROLIDONE…J. NANO- ELECTRON. PHYS. 5, 04063 (2013) 
 
 
04063-3 
 
 
Fig. 3 – Size distribution of the copolymer particles 
 
TGA reveals quite stable copolymer with no weight 
loss up to 100 C. The thermal degradation starts be-
yond 100 C with weight loss of about 5 % from the 
temperature between 100 to 400 C due to the loss of 
adsorbed water molecules. Fig. 4 shows almost the 
same pattern. The TGA thermogram for copolymer and 
copolymer metals composites show  decomposition pat-
tern of one stage with a weight loss of 91.4 % 
(4.464 mg) at the temperature range 400-450 C which 
could be due to the decomposition of the copolymer 
while copolymer /metals compounds shows two weight 
loss stages. The first stage of weight loss is about 
84.4 % (6.762 mg) in the range 380-450 C due to the 
decomposition of the copolymer main chain, then the 
second stage of weight loss 10.03 % (0.8034 mg) at 450-
800 C due to decomposition of metals compounds. The 
differential curve gives the decomposition heat H (the 
enthalpy of decomposition) of 741 J/g. 
The thermal stability of styrene-co-vinylpyrrolidone 
in the presence of the metal is observed to increase 
slightly. 
 
 
Fig. 4 – TGA of styrene co N-vinyl pyrrolidone and copoly-
mer / metals nanocomposites 
 
3.4 Transmission Electron Microscope (TEM) 
 
TEM photos show that the copolymer particles are 
almost in the nanoscale region as shown in (Fig. 5). 
Fig. 6-9 represents TEM of copolymers containing na-
nometal particles and nanometal oxides are all in the 
nanoscale region with size range of 30-7 nm. 
 
 
 
Fig. 5 – TEM of styrene co N-vinyl pyrrolidone 
 
 
 
 
Fig. 6 – TEM of copolymer-Ag nanocomposites Fig. 7 – TEM of copolymer-AgO  nanocomposites 
 AZZA MAZROUAA, ABDELFATAH BADAWI, NAHLA MANSOUR, ET AL. J. NANO- ELECTRON. PHYS. 5, 04063 (2013) 
 
 
04063-4 
 
 
 
Fig. 8 – TEM of copolymer – ZnO nanocomposites  Fig. 9 – TEM of copolymer – CuO nanocomposites 
 
3.5 Electrical Conductivity 
 
Conducting polymers are amorphous with short con-
jugation lengths. Therefore, it has been suggested that 
electrical conduction takes place by charge hopping 
between polymeric chains. When the electric field is 
applied to conducting polymers, it assumes that elec-
tron transport originates from localized or fixed states 
within the polymer chain. The charge transfer between 
the chains takes place by hopping, referred to as photon 
assisted hopping, between two localized states [27]. 
In this study, it is observed from the copolymeriza-
tion of styrene with vinylpyrrolidone that the conduc-
tivity of polystyrene enhanced from the range  
10 – 14 [28] to 10 – 12. The increment in temperature pro-
vides an increase in free volume and segmental mobili-
ty [29]. These two entities then permit free charges to 
hop from one site to another, thus increasing conductiv-
ity. The conductivity increases as temperature indi-
cates more ions gained kinetic energy via thermally 
activated hopping of charge carriers between trapped 
sites, which is temperature dependence.  
The relation between log  – 1.Cm – 1 vs.103 / T, K – 1 
in most cases appear to be similar to that in semicon-
ductors as shown in figure (7). It is clear that the spe-
cific electric conductivity σ of the copolymer/metal and 
metals oxides nanoparticle is in the range of semicon-
ductors between 10 – 10 and 10 + 2 Ohm – 1.Cm – 1,  in-
crease with increase in temperature. The observation of 
increased conductivity with temperature is attributed 
to the thermally activated behavior of the polymer-
inorganic nanocomposite [30, 31].  
It was found that the addition of the metal and 
metal oxides nanoparticle enhance the conductivity of 
copolymer, it is clear from the figure that the highest 
conductivity is in the case of styrene co N-vinyl pyrroli-
done / CuO. Also the conductivity is improved from  
10 – 12 in copolymer to 10 – 10. 
 
 
 
Fig. 10 – (Log ) vs. 103/T, K – 1 of Styrene co N-vinyl pyrroli-
done and copolymer / metals nanocomposites 
 
4. CONCLUSION 
 
Styrene vinylpyrrolidone copolymers are good film 
forming materials and also can be a good base to 
accommodate different nano-particles of metals or their 
oxides which are known to exert antibacterial 
propoerties. The emulsion technique is used for the 
preparation of the copolymer as it gives the highest mo-
lecular weight with particles in size of the nanorange. 
The structures of the copolymer are confirmed by FTIR 
and 1H NMR. The thermal stability of the copolymers 
and their composites are also confirmed using TGA 
which reveals that the prepared compounds are quite 
stable and decompose at about 400 C. The electrical 
conductivity of the prepared compounds was enhanced 
by adding metal or metal oxides. The conductivity is the 
highest in the case of styrene co N-vinyl pyrroli-
done / CuO. It is observed that the conductivity of copol-
ymer / CuO increases with increasing temperature. 
 
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English

Preparation of Emulsion Polymerization from Styrene Vinylpyrrolidone and Studying their Thermal Stability and Electrical Conductivity

Electronic Sumy State University Institutional Repository

JOURNAL OF NANO- AND ELECTRONIC PHYSICS ЖУРНАЛ НАНО- ТА ЕЛЕКТРОННОЇ ФІЗИКИ Vol. 5 No 4, 04063(5pp) (2013) Том 5 № 4, 04063(5cc) (2013)   2077-6772/2013/5(4)04063(5) 04063-1  2013 Sumy State University Preparation of Emulsion Polymerization from Styrene Vinylpyrrolidone and Studying their Thermal Stability and Electrical Conductivity  Azza Mazrouaa1,*, Abdelfatah Badawi1, Nahla Mansour1, Mohamed Fathy1, Maher Elsabee2  1 Petrochemical Department, Egyptian Petroleum Research Institute (EPRI), 1 Ahmed El-Zomor St., Nasr City, 11727 Cairo, Egypt 2 Department of Chemistry, Faculty of Science, Cairo University, 12613 Giza, Egypt  (Received 24 August 2013; published online 31 January 2014)  Copolymer styrene and vinylpyrrolidone were prepared using different techniques. The emulsion polymerization technique was chosen as it gives the highest molecular weight with polymer particles in the nanorange. The polymer nanocomposites were prepared using Pickering emulsion polymerization stabi-lized by adding inorganic nanosized particles. Ag nanometal and nanometal oxides of CuO, ZnO and AgO were added into the copolymer for enhancing its thermal stability and electrical conductivity. The nano-composite chemical structure was confirmed by using FTIR, 1HNMR spectroscopy and TEM. Transmission electron microscopy, TEM photos show that the copolymer particles are almost in the nanoscale region. The thermal stability (TGA) of styrene-co-vinylpyrrolidone in the presence of the nanometal and nanomet-al oxides was slightly increased. The electrical conductivity of these nanocomposites using dc at different temperatures was measured. The data reveal that the nanocomposites are enhanced by adding the nano-metal and nanometal oxides.  Keywords: Styrene, Vinyl pyrrolidone, Copolymer, Emulsion polymerization, Nanometal oxides, FTIR, 1HNMR spectroscopy, TEM and electrical conductivity.   PACS numbers: 47.57.jb, 72.80.Le                                                                   * azza_mazroua2005@yahoo.com 1. INTRODUCTION  Polycarbonate, polymethyl methacrylate, polysty-rene, polyvinyl butyral, polyvinyl carbazole, and vari-ous copolymers can act as polymer stabilizers of nano-particles. Polymers and copolymers of  N-vinylpyrrolidone, ethylene oxide, etc., are used [1-5]. Notably, polyaniline (PANI), polypyrrole (PPy), poly-thiophene (PT), polyacetylene (PA) poly(p-phenylenevinylene (PPV) and their derivatives have attracted the interest of researchers in multidiscipli-nary fields primarily for their unique structural and electronic properties. Nanometer-sized particles have been made from different organic-inorganic particles which impart the composite materials improved prop-erties [6]. Different particles have been used to prepare polymer / inorganic particle nanocomposites, including: metals (Al, Fe, Au, Ag, etc.), metal oxides (ZnO, Al2O3, CaCO3, TiO2 etc.), nanometal oxide (SiO2) [7], and  other (SiC). The selection of nanoparticles depends on the desired thermal, mechanical, and electrical proper-ties of the nanocomposites [8, 9]. Polypyrrole (PPy) nanoparticles in polystyrene (PS) matrix were synthesized by emulsion polymerization using ferric sulfate, sodium dodecyl sulfate, and n-amyl alcohol as an oxidant, emulsifier and dopant, and co-emulsifier, respectively. The content of PPy nanoparti-cles in the composites varied from 14.11 to 34.63 wt %, as calculated from elemental analysis. Field Emission Scanning Electron Microscopy (SEM) images showed spherical nanopartciles of PPy with diameters of 30-74 nm well dispersed in PS matrix. It was found that the thermal stability and electrical conductivity of PS / PPy composites increase with increasing content of PPy nanoparticles [10]. Highly monodisperse polysty-rene (PS) nanospheres were fabricated by surfactant-free emulsion polymerization in water using styrene, 2,2’-azobis (2-methyl propionamidine) dihydrochloride (AIBA), and poly(vinyl pyrrolidone) (PVP) [11]. PS nan-ospheres were produced by surfactant-free emulsion polymerization in water using styrene, 2,2’-azobis (2-methyl propionamidine) dihydrochloride (AIBA), and poly(vinyl pyrrolidone)(PVP).  2. EXPERIMENTAL PART  2.1 Chemicals  N-vinylpyrrolidone (VP), styrene (ST) monomers so-dium hydrogen sulfate (NaHSO4), potassium persulfate (K2S2O8), sodium lauryl sulfate (SLS) silver nanopow-der ( 100 nm, 99 % metal basis), copper (II) oxide na-nopowder ( 50 nm), silver oxide (reagent plus, 99 %), zinc phthalocyanine (ZnPc) and copper phthalocyanine (CuPc) were all supplied from Aldrich.  2.2 Equipment  FT-IR: Was performed using Perkin-Elmer 1650 FTIR spectrophotometer using KBr technique. TGA: All TGA spectra were recorded under a nitro-gen atmosphere up to 800 °C using programmed rate of 10 °C/min. SDT Q600 V20-5 builds 15 with size of  5-1590 mg, Ramp method and range from 10 to 1200 C. TEM: Jeol-JSM Japan Model 2100. Electrical conductivity. The samples were pressed into pellets of 1.33 cm diameter and 1 mm thickness in ahydraulic press (Kimaya Engineers; India; Model WT-324) at five metric ton pressure. The conductivity measurements were carried out by four-probe tech-nique recorded by Keithley electrometer type 6517 A.  AZZA MAZROUAA, ABDELFATAH BADAWI, NAHLA MANSOUR, ET AL. J. NANO- ELECTRON. PHYS. 5, 04063 (2013)   04063-2 The pellet used in this measurement is placed between two copper electrodes; which were connected to the two terminal of Keithley electrometer.  2.3 Emulsion Copolymerization  The reaction was carried out in a flask connected to a condenser system. The reaction mixture was 1/3 molar ratio between (St) and (VP), 18 g water, 0.5 % initiator (2/1 ratio between NaHSO4 and K2S2O8) and 4 % surfactant (SLS). The reaction was carried out at 100 C for 3 hours. The resultant solution was poured in large excess of methanol to destroy the emulsion and  was slowly heated to form large particles that can be filtered. The precipitated polymer was vacuum-filtered and washed several times with methanol and water then dried at 65 C for 10 hours till constant weight.  2.4 Preparation of Copolymer St-VP / Inorganic Nanoparticles  The polymer nanocomposites were prepared using Pickering emulsion polymerization stabilized by adding inorganic nanosized particles. The polymer nanocomposites were prepared using Pickering polymerization in which the emulsion is addi-tionally stabilized by adding inorganic nanosized parti-cles. Theoretical and experimental researches of Picker-ing emulsion polymerization were developed by He [12-14] and Blinks [15, 16]. When the size of inorganic parti-cle is reduced to nanoscale, they are able to assemble on the surfaces of monomer droplets to form a stable dis-persion. After polymerization inorganic / polymer compo-site particles can be obtained. Many kinds of inorganic nanoparticles have been reported to be utilized in Picker-ing emulsion polymerization, including magnetite, cobalt ferrite [17, 18], cerium dioxide [19], titania [20], or silica [21, 22]. Pickering emulsion polymerization provides simple and effective way to prepare inorganic/organic composite materials. Monomers of (St) and (VP) were added at ratio 1/3 with 18 g water, 0.5 % initiator (2/1 ratio between  NaHSO4 and K2S2O8) and 4 % surfactant. The reaction was carried out at 100 C for 3 hours. After 1 hour 3 % of metal nanoparticles was added in-situ to the reaction medium. The resultant solution was poured in large excess of methanol to destroy the emulsion and slowly heated to form large particles that can be filtered. The precipitated polymer was vacuum-filtered and washed several times with methanol and water then dried at 65oC for 10 hours till constant weight.  3. RESULT AND DISCUSSION  3.1 Characterization  GPC: Styrene vinylpyrrolidone copolymers are good film forming materials. They also can be a good base to accommodate different nanoparticles of metals or their oxides. The molecular weight determination of the re-sulting copolymers using micro emulsion method gave the highest molecular weight. Molecular weight deter-mination was done by gel permeation chromatography (GPC) by using CRYETTEA instrument- automatic cryoscope. The method is based on Avogadro-Gerhadt law chromatography (GPC) in THF. It was found that the MW  64581 at 50 %. The structures of the copolymer were confirmed by FTIR (Fig. 1), 1H NMR (Fig. 2). FTIR: The peaks at 1672, 1386 and 1424 cm – 1 are due to CO, C-N-C imide and C-N stretching from the NVP unit. St shows a peak at 3076 cm – 1 (aromatic C-H stretch), 2954 and 2879 cm – 1 (asymmetricand symmet-ric C-H stretch respectively), 1561 (aromatic CC stretch) and 696 cm – 1 (aromatic C-H out of plane bend-ing) [23]. 1 HNMR: Methine proton in N-vinyl pyrrolidone resonates at   3.60, while methylene protons , ,  to the carbonylgroup of NVP resonate between   1.18-2.28 ppm. In styrene, the aromatic protons are assigned at   7.24 ppm and methine protons appear at   2.79 ppm [24, 25]. By using the data from 1 HNMR spectrum, we calculated the percentages of each monomer in the synthesized copolymer which was 70 % St and 30 % VP. This high ratio of styrene, though its low feed ratio (3 : 1 N-vinyl pyrrolidone to styrene), due to its high reactivity ratio which is 15.509 for sty-rene and 0.102 for N-vinyl pyrrolidone [26].    Fig. 1 – FT-IR for styrene co N-Vinyl pyrrolidone    Fig. 2 – NMR for styrene co N-vinyl pyrrolidone  3.2 Size Analysis  Particle size of the prepared copolymer was measured using Malvern zeta-sizer in ethanol after mixing with ethylene glycol. The measurement was performed in triplicate and the median was 79.25 nm as shown in (Fig. 3).  3.3 Thermal Gravimetric Analysis (TGA)  The thermal stability of polymer composites is gen-erally estimated from the weight loss upon heating which results in the formation of volatile products. The change in  sample weight as a function of temperature was observed.  PREPARATION OF EMULSION POLIMERIZATION FROM STYRENE VINYLPYRROLIDONE…J. NANO- ELECTRON. PHYS. 5, 04063 (2013)   04063-3   Fig. 3 – Size distribution of the copolymer particles  TGA reveals quite stable copolymer with no weight loss up to 100 C. The thermal degradation starts be-yond 100 C with weight loss of about 5 % from the temperature between 100 to 400 C due to the loss of adsorbed water molecules. Fig. 4 shows almost the same pattern. The TGA thermogram for copolymer and copolymer metals composites show  decomposition pat-tern of one stage with a weight loss of 91.4 % (4.464 mg) at the temperature range 400-450 C which could be due to the decomposition of the copolymer while copolymer /metals compounds shows two weight loss stages. The first stage of weight loss is about 84.4 % (6.762 mg) in the range 380-450 C due to the decomposition of the copolymer main chain, then the second stage of weight loss 10.03 % (0.8034 mg) at 450-800 C due to decomposition of metals compounds. The differential curve gives the decomposition heat H (the enthalpy of decomposition) of 741 J/g. The thermal stability of styrene-co-vinylpyrrolidone in the presence of the metal is observed to increase slightly.   Fig. 4 – TGA of styrene co N-vinyl pyrrolidone and copoly-mer / metals nanocomposites  3.4 Transmission Electron Microscope (TEM)  TEM photos show that the copolymer particles are almost in the nanoscale region as shown in (Fig. 5). Fig. 6-9 represents TEM of copolymers containing na-nometal particles and nanometal oxides are all in the nanoscale region with size range of 30-7 nm.    Fig. 5 – TEM of styrene co N-vinyl pyrrolidone     Fig. 6 – TEM of copolymer-Ag nanocomposites Fig. 7 – TEM of copolymer-AgO  nanocomposites  AZZA MAZROUAA, ABDELFATAH BADAWI, NAHLA MANSOUR, ET AL. J. NANO- ELECTRON. PHYS. 5, 04063 (2013)   04063-4    Fig. 8 – TEM of copolymer – ZnO nanocomposites  Fig. 9 – TEM of copolymer – CuO nanocomposites  3.5 Electrical Conductivity  Conducting polymers are amorphous with short con-jugation lengths. Therefore, it has been suggested that electrical conduction takes place by charge hopping between polymeric chains. When the electric field is applied to conducting polymers, it assumes that elec-tron transport originates from localized or fixed states within the polymer chain. The charge transfer between the chains takes place by hopping, referred to as photon assisted hopping, between two localized states [27]. In this study, it is observed from the copolymeriza-tion of styrene with vinylpyrrolidone that the conduc-tivity of polystyrene enhanced from the range  10 – 14 [28] to 10 – 12. The increment in temperature pro-vides an increase in free volume and segmental mobili-ty [29]. These two entities then permit free charges to hop from one site to another, thus increasing conductiv-ity. The conductivity increases as temperature indi-cates more ions gained kinetic energy via thermally activated hopping of charge carriers between trapped sites, which is temperature dependence.  The relation between log  – 1.Cm – 1 vs.103 / T, K – 1 in most cases appear to be similar to that in semicon-ductors as shown in figure (7). It is clear that the spe-cific electric conductivity σ of the copolymer/metal and metals oxides nanoparticle is in the range of semicon-ductors between 10 – 10 and 10 + 2 Ohm – 1.Cm – 1,  in-crease with increase in temperature. The observation of increased conductivity with temperature is attributed to the thermally activated behavior of the polymer-inorganic nanocomposite [30, 31].  It was found that the addition of the metal and metal oxides nanoparticle enhance the conductivity of copolymer, it is clear from the figure that the highest conductivity is in the case of styrene co N-vinyl pyrroli-done / CuO. Also the conductivity is improved from  10 – 12 in copolymer to 10 – 10.    Fig. 10 – (Log ) vs. 103/T, K – 1 of Styrene co N-vinyl pyrroli-done and copolymer / metals nanocomposites  4. 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Preparation of Emulsion Polymerization from Styrene Vinylpyrrolidone and Studying their Thermal Stability and Electrical Conductivity

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