Please use this identifier to cite or link to this item: https://hdl.handle.net/20.500.12104/43575
Title: Heterophase polymerization of different methacrylates: Effect of alkyl ester group on kinetics and colloidal behavior
Author: Mejia-Uriarte, E.V.
Sato-Berru, R.Y.
Navarrete, M.
Villagran-Muniz, M.
Medina-Gutierrez, C.
Frausto-Reyes, C.
Murrieta S, H.
Issue Date: 2006
Abstract: Sound velocity changes of unpolarized polycrystalline BaTiO3, in the diamond anvil cell (DAC) up to 6.8 GPa, across the tetragonal to cubic phase transition at room temperature (RT) have been detected by a photoacoustic technique. The light absorption before, during, and after the structural phase transformation shows changes. This is very clear using a photoacoustic method where a pulsed laser is used as a standard source of ultrasound. The phase transition is recognized by a profile generated through sequence values of the temporal peak positions acquired from sequential measurements of the pulsed photoacoustic signal (PA) obtained for each pressure applied. The results are in agreement with those obtained by high-pressure Raman spectroscopy carried out under similar conditions. In both techniques a 4:1 methanol-ethanol mixture was used as a pressure transmitting medium, and the pressure was calibrated using the ruby fluorescence technique. " 2006 IOP Publishing Ltd.",,,,,,"10.1088/0957-0233/17/6/005",,,"http://hdl.handle.net/20.500.12104/43575","http://www.scopus.com/inward/record.url?eid=2-s2.0-33646885920&partnerID=40&md5=6c8a5537208286e468f000dbcd24238a",,,,,,"6",,"Measurement Science and Technology",,"1319
1323",,"17",,"Scopus
WOS",,,,,,"High pressure; Phase transition; Photoacoustic; Raman",,,,,,"Phase transition of polycrystalline BaTiO3 at high-pressure detected by a pulsed photoacoustic technique",,"Conference Paper" "43635","123456789/35008","Contreras Estrada, M.I., Instituto de Investigación en Salud Ocupacional, Departamento de Salud Pública, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Mexico; Baltazar, R.G., Instituto de Investigación en Salud Ocupacional, Departamento de Salud Pública, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Mexico; Cortes, S.L., Instituto de Investigación en Salud Ocupacional, Departamento de Salud Pública, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Mexico; Rodríguez, G.A., Instituto de Investigación en Salud Ocupacional, Departamento de Salud Pública, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Mexico; Santacruz, G.H., Departamento de Fisiología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Mexico",,"Contreras Estrada, M.I.
Baltazar, R.G.
Cortes, S.L.
Rodriguez, G.A.
Santacruz, G.H.",,"2014",,"Objectives: The aim of this study was to explore the social meaning of health self-care for women in the informal sector (street market or "tianguis") a gender perspective. Subjects and methods: This was a qualitative study based on the theory of social meanings. Design: A Case Study. Techniques used: field observation and interviews with 6 women in informal work three "tianguis". Selected by purposive sampling. They were recorded and analyzed through thematic content analysis supported by Atlas Ti. Results: Emphasizes that women expressed a desire to change their lives, saying that they feel worried, tired and stressed. They indicate that in this kind of work there are feelings of happiness, love and joy. In the domain of the meaning of health they said they are healthy, but they justified and symbolize as anger not having time for medical checkup. Conclusion: From this perspective, participants make visible this work as not well recognized and sacrificed as well. They indicate that they are willing to receive information to be better in their families and keep fighting against all odds of inequality, injustice and inequality at work.",,,,,,,,,,"http://www.scopus.com/inward/record.url?eid=2-s2.0-84901658272&partnerID=40&md5=194faa782a2d5b268956e21192603fc7
http://hdl.handle.net/20.500.12104/41856",,,,,,"1",,"Salud Uninorte",,"1
9",,"30",,"Scopus",,,,,,"Gender; Self-care; Subjectivity; Women",,,,"Health self-care in informal sector female workers in Guadalajara (Mexico). A gender perspective [Autocuidado de la salud en trabajadoras del sector informal en Guadalajara (México) Una perspectiva de género]",,,,"Article", "43667","123456789/35008",,"Ovando-Medina, V.M., Ingeniería Química, COARA, Universidad Autónoma de San Luis Potosí, Matehuala San-Luis-Potosí 78700, Mexico; Corona-Rivera, M.A., Ingeniería Química, COARA, Universidad Autónoma de San Luis Potosí, Matehuala San-Luis-Potosí 78700, Mexico; Márquez-Herrera, A., Ingeniería Mecúnica Administrativa, COARA, Universidad Autónoma de San Luis Potosí, Matehuala San-Luis-Potosí 78700, Mexico; Lara-Ceniceros, T.E., Centro de Investigación en Materiales Avanzados, Parque de Investigación e Innovación Tecnológica, Alianza Norte 202, Apodaca-Nuevo-León 66600, Mexico; Manríquez-González, R., Departamento de Madera, Celulosa y Papel, CUCEI, Universidad de Guadalajara, Jalisco 45020, Mexico; Peralta, R.D., Centro de Investigación en Química Aplicada, Saltillo Coahuila 25100, Mexico",,"Ovando-Medina, V.M.
Corona-Rivera, M.A.
Marquez-Herrera, A.
Lara-Ceniceros, T.E.
Manriquez-Gonzalez, R.
Peralta, R.D.",,"2014",,"In this article, methyl- (MMA), ethyl- (EMA), n-butyl- (BMA), n-hexyl (HMA), and 2-ethyl hexyl (2-EHMA) methacrylates were homopolymerized in heterophase at 60°C using sodium dodecyl sulfate as surfactant and potassium persulfate as initiator. The effects of monomer content in the reaction mixture (2.5 and 3.5 wt %) and the alkyl ester groups of the methacrylates on the kinetics, average particle diameter (Dp), molar masses, tacticity, and glass transition temperature (Tg) were studied. The final weight average molecular weights were in the range of 4.53 105 to 2.78 106 g/mol with polydispersities between 1.7 and 3.1 for different methacrylates. For 2.5 wt % of monomer concentration, the order of increase in polymerization rate was RpHMA>RpBMA> Rp2-EHMA > RpEMA>RpMMA, whereas for 3.5 wt % of monomer concentration was RpBMA>RpHMA> Rp2-EHMA>RpEMA>RpMMA. This behavior was ascribed to the differences in the water solubility, monomer partitioning between the different phases, and monomers reactivity. The Dp values varied between 42 and 65 nm, increasing according to the hydrophobicity of each monomer. 13C-NMR (nuclear magnetic resonance) and differential scanning calorimetry analysis demonstrated that 79-87% of syndiotactic configuration was obtained for the different polymers. The steric effect of the alkyl ester length in the methacrylates contributed directly to promote the syndiotactic configuration. Nevertheless, Tg values (between -7 and 120°C) for these polymers decreased when the alkyl ester length increased. " 2013 Wiley Periodicals, Inc.
URI: http://hdl.handle.net/20.500.12104/41888
http://www.scopus.com/inward/record.url?eid=2-s2.0-84901809762&partnerID=40&md5=bf3232c9bce787b8bec55ca479100fd0
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