scholarly journals Synthesis and kinetic studies of TiO2/polystyrene composite particles by emulsion polymerization

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhang Jianmin ◽  
Peng Zheng ◽  
Sun Xiuguo ◽  
Wang Caihui ◽  
Gao Jungang

AbstractIn the presence of titanium dioxide (TiO2) nanoparticles, emulsion polymerization of styrene with sodium dodecyl sulphate (SDS) as an emulsifier and potassium persulphate as an initiator was investigated in detail. It was shown that SDS concentration influences the morphology of the composite particles in higher degree. Moreover, the effects of operating variables such as emulsifier concentrations, initiator concentration, monomer concentration, and polymerization temperature on the kinetic features were also examined. The kinetic data showed that at conditions studied, the rate of polymerization over interval II was proportional to the 0.68 power of the initial emulsifier concentration, to the 2.2 power of the initial initiator concentration and to the 1.6 power of the initial monomer‟s concentration. The initiator concentration has a dominant effect on the rate of the polymerization. The appropriate conditions for polymerization were obtained when emulsifier concentration of 6.5×10-3 mol·L-1, initiator concentration of 4.4×10-3 mol·L-1, the polymerization temperature of 75 °C and the initial monomer‟s concentration of 0.288 mol·L-1 were used. The polymerization rate obtained is more favorable than that of the conventional emulsion approach. The experimental results can be reasonably ascribed to the nucleation mechanism of “TiO2/SDS” micelles in the emulsion polymerization of styrene.

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Satoshi Kato ◽  
Kiyoshi Suzuki ◽  
Mamoru Nomura

AbstractA copolymer of methyl methacrylate and methacrylic acid to be used as a polymeric surfactant was synthesized by emulsifier-free semi-batch emulsion copolymerization. Emulsion polymerization of styrene was carried out at 50°C utilizing the ammonium salt of the copolymer as the polymeric emulsifier and potassium persulfate as the initiator, respectively. Both the number of polymer particles produced and the rate of polymerization were proportional to the 0.6 power of the initial emulsifier concentration, to the 0.4 power of the initial initiator concentration, and independent of the initial monomer concentration, respectively. These relationships are almost the same as those observed in the emulsion polymerization of styrene conducted using conventional surfactants like sodium dodecyl sulfate as the emulsifier and potassium persulfate as the initiator.


2013 ◽  
Vol 821-822 ◽  
pp. 945-948
Author(s):  
Hui Rong Yang ◽  
Chuan Shan Zhao ◽  
Xue Zhang ◽  
Wen Jia Han

initiator is one of the most important conditions of synthesizing efficient strength agent CPAM. To begin with initiating mechanism, three redox systems of acrylamide aqueous polymerization (NH4)2S2O8/ Na2SO3, K2S2O8/NaHSO3and K2S2O8/Na2S2O4have been studied. The effects of different kinds of initiator, initiator concentration, and monomer concentration as well as polymerization temperature on relative molecular weight and strength effects of CPAM have been investigated. K2S2O8/Na2SO3is the most useful system in synthesizing efficient strength agents.


2012 ◽  
Vol 554-556 ◽  
pp. 236-239
Author(s):  
Shi Gao Song ◽  
Shao Guo Wen ◽  
Ji Hu Wang ◽  
Yan Shen

In this paper, we studied the influence of the amount of alkyl glycosides emulsifier, reaction temperature and the amount of initiator on emulsion polymerization kinetics. The results show that when we apply the new alkyl glycosides emulsifier in acrylic emulsion polymerization, the relationship between polymerization rate Rp and emulsifier concentration [S] is Rp∝[S]0.70 and the correlation coefficient is 0.93; the relationship between polymerization rate Rp and the initiator concentration [I] is Rp∝[I]1.00 and the correlation coefficient is 0.86; the apparent activation energy of polymerization is 32.34KJ/mol and the correlation coefficient is 0.93. We got good results after applying the new type emulsifier in acrylic emulsion polymerization.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Shirley Carro ◽  
Valeria J. Gonzalez-Coronel ◽  
Jorge Castillo-Tejas ◽  
Hortensia Maldonado-Textle ◽  
Nancy Tepale

Inverse emulsion polymerization technique was employed to synthesize hydrophobically modified polyacrylamide polymers with hydrophobe contents near to feed composition. Three different structures were obtained: multisticker, telechelic, and combined. N-Dimethyl-acrylamide (DMAM), n-dodecylacrylamide (DAM), and n-hexadecylacrylamide (HDAM) were used as hydrophobic comonomers. The effect of the hydrophobe length of comonomer, the initial monomer, and surfactant concentrations on shear viscosity was studied. Results show that the molecular weight of copolymer increases with initial monomer concentration and by increasing emulsifier concentration it remained almost constant. Shear viscosity measurements results show that the length of the hydrophobic comonomer augments the hydrophobic interactions causing an increase in viscosity and that the polymer thickening ability is higher for combined polymers.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 749
Author(s):  
Hua Zou ◽  
Yiqian Wang

Synthesis of conjugated polymer-coated latex particles is an effective method to improve the poor processability of conjugated polyheterocycles. The key to success is to control the overlayer thickness so it is less than the size of the solvated layer of polymeric stabilizer. This paper presents a protocol to coat polymer latex particles with poly(2-aminothiazole) (PAT), which is a relatively new heterocyclic conjugated polymer. The protocol is based on chemical oxidative polymerizations of 2-aminothiazole using copper chloride as the oxidant at a fixed oxidant/monomer molar ratio of 0.5 in aqueous media in the presence of poly(N-vinyl-2-pyrrolidone)-functionalized polystyrene (PS) latex. The effects of monomer concentration, PS concentration, and polymerization temperature on the morphology of the PAT-coated PS composite particles were investigated by SEM and TEM, and the resulting composite particles characterized by FTIR and XPS. Optimization of the initial monomer concentration allowed colloidally stable PAT-coated PS composite particles to be formed at ambient temperature, and the PAT loading was easily adjusted by varying the initial PS concentration. The Hg(II) adsorption properties of selected PAT-coated PS composite particles were assessed preliminarily. The maximum adsorption capacity at 25 °C reached 440.25 mg/g, which is much higher than many other adsorbents.


e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Kiyoshi Suzuki ◽  
Yasutaka Yamada ◽  
Kazumi Fujita ◽  
Mamoru Nomura ◽  
Hideya Saito

AbstractIn order to clarify the kinetics and mechanism of miniemulsion polymerization of a sparingly water-soluble monomer, the miniemulsion polymerization of 1,1,2,2-tetrahydroperfluorodecyl acrylate was conducted at 50°C using potassium persulfate as initiator and sodium dodecyl sulfate as emulsifier, respectively. It was found that the rate of polymerization was proportional to the 0.65 power of the initial initiator concentration and to the 0.30 power of the number of miniemulsion droplets (latex particles). It is pointed out that the kinetics of this polymerization system may be subject to the modified case III kinetics of emulsion polymerization with predominant bimolecular termination in the aqueous phase.


2012 ◽  
Vol 476-478 ◽  
pp. 1408-1411
Author(s):  
Xin Fan ◽  
Qiu Ju Qin ◽  
Xiu Fang Wen ◽  
Jiang Cheng ◽  
Zhuo Ru Yang

In this paper raspberry-like composite particles were prepared via cationic soap-free emulsion polymerization with silica sol as stabilizer and 2-(methacryloyl) ethyltrimethylammonium chloride (MTC) as cationic auxiliary monomer. According to the TGA and TEM results we could find that the electrostatic attraction supplied by MTC played a vital role in the adsorption of silica particles as well as the generation of raspberry-like morphology. The silica content and appearance of composite particles were found to be improved with the increasing amount of silica sol and MTC while varied little with changes of AIBA amount.


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaohui He ◽  
Yiwang Chen ◽  
Yongming Liu ◽  
Muqing Chen ◽  
Shuxian Yu ◽  
...  

AbstractThe polymerizations of n-butyl methylacrylate (nBMA) were carried out using bis(β-ketoamino)nickel(II) complexes (Ni[CH3C(O)CHC(NR)CH3]2: R = phenyl, 1; R = naphthyl, 2) in combination with methylaluminoxane (MAO) in toluene. The effect of parameters such as polymerization temperature, Al/Ni molar ratios, polymerization time, and monomer concentration, on catalytic polymerization activity and polymer molecular weights, were examined in detail. Both of the nickel(II) catalytic systems exhibited moderate activity, and produced P(nBMA) with high molecular weight and relatively broad molecular weight distribution (Mw/Mn=2.0~3.0. The obtained polymer has been characterized by means of FTIR, 1H NMR, 13C NMR, DSC, and WAXD technique and was confirmed to be syndio-rich stereospecific P(nBMA).


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