Encapsulation of silica nanoparticles by poly(methyl methacrylate-co-styrene) via emulsion polymerization using dimethylaminoethyl methacrylate

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Mohammad Barari ◽  
Naser Sharifi-Sanjani
Keyword(s):  
Methyl Methacrylate ◽  
Silica Nanoparticles ◽  
Emulsion Polymerization ◽  
Monomer Concentration ◽  
Molar Ratio ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Potential Measurement ◽  
Emulsion Copolymerization ◽  
Dimethylaminoethyl Methacrylate

AbstractEncapsulation of silica nanoparticles was performed by emulsion copolymerization of methyl methacrylate (MMA) and styrene (St) using dimethylaminoethyl methacrylate (DM) as an auxiliary monomer. The emulsion polymerization was performed in the presence of silica nanoparticles as the seed to obtain encapsulated silica nanoparticles with polymer content and average particle sizes ranged from 35 wt. % to 85 wt. % and 114 to 272 nm respectively. Electrostatic attraction between anionic surface of silica beads and cationic amino groups of DM is the main driving force for the encapsulation of the silica nanoparticles. The influence of MMA, St and DM concentration on the coating of the silica nanoparticles was studied. It was demonstrated that DM has an important role in stabilizing the system. Transmission electron microscopy showed that coreshell structures with silica particles as core were coated with the polymer, of which the amount and morphology were influenced by the total monomer concentration and molar ratio of MMA to St. Zeta potential measurement confirmed the presence of DM on the surface of composite particles. Thermogravimetric analysis showed that the incorporation of silica in polymer matrix results in an enhancement of thermal stability in the encapsulated products. Differential scanning calorimetry studies indicated that the glass transition temperature of encapsulated particles can be either higher or lower than those of the pure terpolymer counterpart, depending on the DM content of the polymer shell. The products were also characterized by FT-IR spectroscopy.

Synthesis and characterization of poly(methyl methacrylate) obtained by ultrasonic irradiation

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Cristina Parra ◽  
Gema González ◽  
Carmen Albano
Keyword(s):  
Methyl Methacrylate ◽  
Cationic Surfactant ◽  
Anionic Surfactant ◽  
Average Particle Size ◽  
Monomer Concentration ◽  
Average Particle ◽  
Lauryl Sulfate ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Poly Methyl Methacrylate

AbstractWe have studied the influence of surfactant nature and concentration, and monomer concentration on the synthesis of poly(methyl methacrylate) (PMMA) using high-frequency ultrasound. Polymerization was carried out via free radicals from aqueous solutions with several concentrations of an anionic (sodium lauryl sulfate, SLS) or a cationic surfactant (cetyltrimethylammonium bromide, CTAB) and different concentrations of the insoluble monomer methyl methacrylate (MMA) as the dispersed phase. The polymer particles obtained were characterized by FTIR, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The IR spectra show the presence of the characteristic absorption bands for PMMA when SLS was used. When CTAB was employed, for all surfactant concentrations and high monomer concentration (14% v/v), PMMA was obtained. However, bands of the surfactant were present for lower monomer concentrations. The glass transition temperature measured by DSC was in the range 106 - 126°C characteristic of PMMA. Maximum conversion was obtained when the anionic surfactant was employed. SEM studies show the formation of sub-micrometric PMMA latex spheres with average particle size from 65 to 100 nm when the anionic surfactant was used and 65 nm - 0.3 μm for the cationic surfactant.

Synthesis of n-octadecane/poly (styrene-methyl methacrylate) (St-MMA) energy-storage microcapsules via emulsion polymerization

2017 ◽  
Vol 31 (11) ◽  
pp. 1443-1454
Author(s):  
Weili Wu ◽  
Zhe Chen
Keyword(s):  
Particle Size ◽  
Energy Storage ◽  
Methyl Methacrylate ◽  
Phase Change ◽  
Emulsion Polymerization ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Size Dispersion

Poly (methyl methacrylate) block copolymer is interesting due to its good compatibility with many polymers. In this study, a novel phase-change energy storage material, n-octadecane/poly (styrene-methyl methacrylate) (OD/P(St-MMA)) microcapsules, were designed and synthesized by emulsion polymerization, in which n-OD was used as core materials, the copolymer of St and MMA as shell materials, and sodium dodecyl benzene sulfonate (SDBS) as emulsifier. The morphology, phase-change thermal properties and thermal stability of microcapsules were investigated by particle size analyzer, transmission electron microscope, thermogravimetric (TG) analyzer, and differential scanning calorimetry (DSC). The results showed that when the ratio of the two monomers, St and MMA, was 1/5 and the dosage of SDBS was 1.5 g (3% of the total mass), the particle size dispersion of microcapsules was uniform and microcapsule particles were well wrapped. TG analysis showed that the long-term use temperature of microcapsules could not exceed 131°C. DSC showed that the phase-change enthalpy of microcapsule was 148.39 J·g−1, which indicated the microcapsules had excellent energy storage property.

scholarly journals The effect of the polar solvents on the synthesis of poly(urethane-urea-siloxane)s

2012 ◽  
Vol 77 (10) ◽  
pp. 1457-1481 ◽  
Author(s):  
Milica Balaban ◽  
Vesna Antic ◽  
Marija Pergal ◽  
Iolanda Francolini ◽  
Andrea Martinelli ◽  
...  
Keyword(s):  
Monomer Concentration ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Solvent Ratio ◽  
Solvent Mixtures ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Water Contact ◽  
Soft Segments ◽  
Hard Segments

Segmented poly(urethane-urea-siloxanes) (PUUS) based on 4,4?- methylene diphenyl diisocyanate-ethylene diamine (MDI-ED) hard segments and hidroxypropyl-terminated poly(dimethylsiloxane) (PDMS, M n =1000 g mol-1) soft segments were prepared under various experimental conditions. The copolymers with constant molar ratio of hard and soft segments (PDMS:MDI:ED = 1:2:1; 20 wt. % of the hard segments) were synthesized in two different solvent mixtures, by two-step polyaddition procedure. The first one was THF/DMAc with different co-solvent ratio (1/1, 1/2 and 1/9, v/v), whereas the second one was THF/NMP (1/9, v/v). The reaction conditions were optimized by varying the co-solvents ratio, the concentration of the catalyst, the initial monomer concentration, as well as the time of the first and the second step of reaction. The effect of the experimental conditions on the size of PUUS was investigated by gel permeation chromatography (GPC) and viscometry of the dilute solutions [?]. The copolymers with the highest molecular weights were obtained in the THF/NMP mixture (1/9, v/v). The structure and composition of the copolymers were determined by 1H NMR and FTIR spectroscopy. The morphology of the synthesized copolymers was investigated by atomic force microscopy (AFM), while the thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The surface properties were evaluated by measuring the water contact angle (WCA). The copolymers showed phase separated microstructure and were stable up to 200?C in nitrogen.

Design and Synthesis of Novel Hematite Core-Shell Polymeric Composites

2012 ◽  
Vol 627 ◽  
pp. 869-872
Author(s):  
Hong Wang ◽  
Xue Fei Li ◽  
Ying Wang ◽  
Jiao Ren
Keyword(s):  
Methyl Methacrylate ◽  
Chemical Interaction ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Emulsion Copolymerization ◽  
Design And Synthesis ◽  
Structure Morphology ◽  
Methacrylate Monomer ◽  
Higher Temperature

A novel synthetic method was developed for the preparation of core-shell composites consisting of α-Fe2O3cores with poly(styrene-co-methyl methacrylate) (P(St-co-MMA)) shells via emulsion copolymerization of styrene and methyl methacrylate monomer with surfactant of PVP. The structure, morphology and thermal properties of the composites were been characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The results confirmed that there was no chemical interaction between α-Fe2O3and copolymer, and the onset of thermal decomposition for nanocomposites shifted to a higher temperature than that for neat copolymer.

SYNTHESIS AND CHARACTERIZATION OF POLY(BUTYL ACRYLATE-CO-METHYL METHACRYLATE)/CLAY NANOCOMPOSITES VIA EMULSION POLYMERIZATION

2006 ◽  
Vol 05 (02n03) ◽  
pp. 291-297 ◽  
Author(s):  
ZHIYI ZHANG ◽  
NING ZHAO ◽  
WEI WEI ◽  
DONG WU ◽  
YUHAN SUN
Keyword(s):  
Methyl Methacrylate ◽  
Emulsion Polymerization ◽  
Butyl Acrylate ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Clay Nanocomposites ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Dodecyl Benzene Sulfonate ◽  
Clay Layers

Poly(butyl acrylate-co-methyl methacrylate)/clay nanocomposites were synthesized via emulsion polymerization with an emulsifier (sodium dodecyl benzene sulfonate, SDBS), an initiator (ammonium persulate, APS), acrylic acid ester monomer and Na -montmorillonite. It was found that the addition of SDBS and water widened the gap between clay layers and facilitated monomers to penetrate into clay. Through initiator, comonomers were polymerized in the montmorillonite galleries. The structure of extracted nanocomposites was confirmed by XRD, transmission electron microscopy (TEM). Their thermal property and molecule weight were investigated by differential scanning calorimetry (DSC) and gel-penetrate chromatogram (GPC).

scholarly journals Methyl Methacrylate and Alpha-Methyl Styrene: New Strategy for Synthesis of Bloc Copolymers for Use in Potential Biomedical Applications Generated by an Ecologic Catalyst Called Maghnite (Algerian MMT)

2016 ◽  
Vol 11 (3) ◽  
pp. 316 ◽  
Author(s):  
Moulkheir Ayat ◽  
Mohamed Belbachir ◽  
Abdelkader Rahmouni
Keyword(s):  
Methyl Methacrylate ◽  
Cationic Polymerization ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Monomer Concentration ◽  
Molar Ratio ◽  
Efficient Catalyst ◽  
H Nmr ◽  
New Strategy ◽  
Methyl Styrene

<p>A new model for synthesis of the plastics, block copolymers were prepared from methyl methacrylate (MMA) and alpha-methyl styrene (α-MS) by cationic copolymerization in the presence of a new and efficient catalyst of “Maghnite-Na” at 0 °C in bulk. In this paper, the copolymerization of α-MS and MMA was induced in heterogeneous phase catalyzed by Maghnite-Na was investigated under suitable conditions. The “Maghnite-Na” is a montmorillonite sheet silicate clay, with exchanged sodium cations to produce Na-Montmorillonite (Na<sup>+</sup>-MMT) obtained from Tlemcen, Algeria, was investigated to remove heavy metal ion from wastewater as an efficient catalyst for cationic polymerization of many vinylic and heterocyclic monomers. The synthesized copolymer were characterized by Nuclear Magnetic Resonance (NMR-<sup>1</sup>H, NMR-<sup>13</sup>C), FT-IR spectroscopy, Differential Scanning Calorimetry (DSC), and Gel Permeation Chromatography (GPC) to elucidate structural characteristics and thermal properties of the resulting copolymers. The structure compositions of “MMT”, “H<sup>+</sup>-MMT” and “Na<sup>+</sup>-MMT” have been developed. The effect of the MMA/α-MS molar ratio on the rate of copolymerization, the amount of catalyst, temperature and time of copolymerization on yield of copolymers was studied. The yield of copolymerization depends on the amount of Na<sup>+</sup>-MMT used and the reaction time. The kinetic studies indicated that the polymerization rate is first order with respect to monomer concentration. A possible mechanism of this cationic polymerization is discussed based on the results of the <sup>1</sup>H-NMR Spectroscopic analysis of these model reactions. A cationic mechanism for the reaction studies showed that monomer was inserted into the growing chains. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 2<sup>nd</sup> May 2015; Revised: 24<sup>th</sup> February 2016; Accepted: 15<sup>th</sup> March 2016</em></p><p><strong>How to Cite:</strong> Ayat, M., Belbachir, M., Rahmouni, A. (2016). Methyl Methacrylate and Alpha-Methyl Styrene: New Strategy for Synthesis of Bloc Copolymers for Use in Potential Biomedical Applications Generated by an Ecologic Catalyst called Maghnite (Algerian MMT). <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (3): 316-329 (doi: 10.9767/bcrec.11.3.571.316-329)</p><p><strong>Permalink/DOI:</strong> <a href="http://doi.org/10.9767/bcrec.11.3.571.316-329">http://doi.org/10.9767/bcrec.11.3.571.316-329</a></p>

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