Kinetic analysis of the RAFT copolymerization of styrene and maleic anhydride by differential scanning calorimetry


Por: Benvenuta-Tapia J.J., Vivaldo-Lima E., Tenorio-López J.A., de los Ángeles Vargas-Hernández M., Vázquez-Torres H.

Publicada: 10 sep 2018
Resumen:
A kinetic study of the copolymerization of styrene (S) and maleic anhydride (MA) in the presence of dibenzyl trithiocarbonate (DBTTC) as RAFT agent monitored by differential scanning calorimetry, is presented. The results obtained indicate that the polymerization proceeded in a controlled manner. The average activation energy (E) of the copolymerization obtained by Ozawa and Kissinger methods (62 ± 2 kJ mol-1) showed good agreement with the E value obtained by the isothermal method (67 ± 2 kJ mol-1). These values agree well with the value of 65 kJ mol-1 reported for the nitroxide-mediated copolymerization of S and MA. Calculations using isoconversional methods show that Ea is not constant within the whole conversion range. As the reaction proceeds and higher conversions are reached, Ea decreases to lower values due to diffusion-controlled effects. A first-order reaction model is applied to determine overall kinetic rate constants at different temperatures and different MA molar feed fractions. Polymerization rate increased approximately four orders of magnitude when temperature changed from 90 °C to 110 °C. Polymerization rate is also strongly affected by MA content. It increased by a factor of about three when MA changed from 30% to 50% molar content in the copolymer. © 2018 Elsevier B.V.

Filiaciones:
Benvenuta-Tapia J.J.:
 Facultad de Química, Departamento de Ingeniería Química, Universidad Nacional Autónoma de México, Ciudad de México, México

Vivaldo-Lima E.:
 Facultad de Química, Departamento de Ingeniería Química, Universidad Nacional Autónoma de México, Ciudad de México, México

Tenorio-López J.A.:
 Facultad de Ciencias Químicas, Universidad Veracruzana, Coatzacoalcos, Veracruz, Mexico

de los Ángeles Vargas-Hernández M.:
 Facultad de Ciencias Químicas, Instituto Tecnológico de Ecatepec, Estado de México, Mexico

Vázquez-Torres H.:
 Departamento de Física, Universidad Autónoma Metropolitana, Ciudad de México, Mexico
ISSN: 00406031
Editorial
Elsevier, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, Países Bajos
Tipo de documento: Article
Volumen: 667 Número:
Páginas: 93-101
WOS Id: 000444663600012