Radiofrequency (RF) plasma polymerization is a convenient thin film deposition process as it facilitates the synthesis of polymer films with stable physico-chemical properties suitable for various applications in microelectronic, optical, and biomedical fields. The unique properties of these plasma polymerized films as compared to the conventional ones are strongly related to the proper adjustment of the external plasma discharge parameters and selection of suitable monomer. It is also important to study the fundamental chemistry of RF plasma polymerization process, so that one can successfully correlate the internal features of the discharge with the film properties and explore their possible technological applications. The possibility of using styrene-based plasma polymer (SPP) films on bell metal as protective coatings is explored in this work. Depositions of the films are carried out in RF Ar/styrene discharge at working pressure of 1.2´10-1 mbar and at the RF power range of 20 to 110 W. Optical emission spectroscopy (OES) is used to study the active species generated during plasma polymerization, while Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) are used to analyze the internal chemical structures of the films. The protective performances of the SPP films are attempted to correlate with the results obtained from OES, FT-IR, and XPS analyses.

Laboratory runs can be minimized via experimental design which yields the optimum and best data regarding the independent parameters. In this research work, response Surface methodology (RSM) based on a threelevel central composite design (CCD) was utilized to optimize and evaluate the interactive effects of processing conditions for polymerization of 1, 3-butadiene (Bd) diene monomer using Ziegler-Natta catalyst. The polybutadiene rubber (PBR) having different cis content and molecular weight was obtained. The catalyst components included neodymium versatate (NdV3) as catalyst, triethyl aluminum (TEAL) as cocatalyst or activator, and ethylaluminum sesquichloride (EASC) as chloride donor. For the modeling, three independent variables, namely monomer concentration (8-28 wt%), reaction time (1. 5-2. 5 h), and reaction temperature (45-75º, C) at three levels were selected to optimize the dependent variables or responses including monomer conversion, viscosity-average molecular weight and the cis isomer content of the obtained polymer. The interaction between three crucial parameters was studied and modeled. Quadratic models were obtained to relate process conditions to dependent variables. It was observed that the optimal conditions predicted by RSM were consistent with the experimental data. Statistical analysis demonstrated that concentration of the monomer and the time of reaction significantly affected cis content. Moreover, processing conditions to achieve the desired response variables were predicted and experimentally approved. The optimal reaction conditions derived from RSM are monomer concentration = 19 wt%, polymerization time = 2 hours, and polymerization temperature = 50º, C. polymerization was carried out at optimum conditions. The appropriate level of dependent variables including 94. 2% monomer conversion, 151812 g/mol viscosity-average molecular weight and 98. 8% cis content was acquired.

Sulfonated polymer/silica hybrid nanoparticles were prepared by free radical polymerization of 2-acrylamido-2-methyl-1-propane sulfonic acid (PAMPS-g-SN) and styrene sulfonic acid sodium salt (PSSA-g-SN), initiated on the Surfaces of amino propyl-functionalized silica nanoparticles (ASN). Ce (IV) ammonium nitrate/nitric acid and sodium dodecyl sulfate were used as redox initiator and stabilizer, respectively. ASN Nanoparticles were synthesized by a covalently attached 3-aminopropyltriethoxysilane onto the Surface of silica nanoparticles. Sulfonated monomers (AMPS or SSA) were then grafted onto the ASN nanoparticles, ultrasonically dispersed in water, using redox initiator system at 40°C. ASN, PAMPS-g-SN and PSSA-g-SN nanoparticles were characterized by Fourier transform infrared (FTIR), thermogravimetry, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. FTIR and TGA results indicated that both AMPS and SSA monomers were successfully grafted onto the silica nanoparticles. The grafted amounts of sulfonated polymers onto the silica nanoparticles were estimated from TGA thermo grams to be 46 and 22 % for PAMPS and PSSA, respectively. From SEM and TEM micrographs, the average-diameters of the polymer-grafted silica nanoparticles were measured to be < 50 nm with a (semi) spherical morphology, in which several silica nanoparticles were able to form a core with PAMPS or PSSA existing around the silica nanoparticles.

Response Surface methodology was used to investigate the kinetics of slurry homopolymerization of ethylene which was catalyzed by soluble metallocene catalytic system of Cp2ZrCl2/MAO. polymerization temperature, monomer pressure, and molar ratio of cocatalyst to catalyst were considered as the main parameters which affect catalyst activity and viscosity average molecular weight of the final product. A Box-Behnken design was used to produce models for objective responses based on parameters that have significance probabilities (P-value<0.1). It was developed by using the three parameters at three levels including 50, 60, and 70°C for temperature; 2, 4, and 6 bar for pressure; and 3219, 4828.5, and 6438 for molar ratios of cocatalyst to catalyst. Analysis of variance showed that monomer pressure is the most affecting parameter on catalyst activity (P-value<0.0001). It was found that at high levels of cocatalyst concentration, the further increase of its concentration to higher levels decreases the catalyst activity which can be attributed to excessive complexation of MAO with active centres. polymerization temperature was found to show the significant effect on viscosity average molecular weights of polymers (P-value = 0.0002). It is believed that higher activation energies of chain transfer and deactivation reactions relative to propagation reaction decrease the molecular weight at elevated temperatures. At higher molar ratio of cocatalyst to catalyst, molecular weight also decreases because of more chain transfer to cocatalyst.