Pyrolysis-gas chromatography-mass spectrometry for studying N-vinyl-2-pyrrolidone-co-vinyl acetate copolymers and their dissolution behaviour.
Anal Chim Acta
; 706(2): 305-11, 2011 Nov 14.
Article
en En
| MEDLINE
| ID: mdl-22023866
Knowledge on the solubility behaviour and dissolution rate of speciality and commodity polymers is very important for the use of such materials in high-tech applications. We have developed methods for the quantification and characterization of dissolved copolymers of N-vinyl-2-pyrrolidone (VP) and vinyl acetate (VA) during dissolution in water. The methods are based on pyrolysis (Py) performed in a programmed-temperature vaporization injector with subsequent identification and quantification of the components in the pyrolysate using capillary gas chromatography-mass spectrometry (GC-MS). By injecting large volumes and applying cryo-focussing at the top of the column, low detection limits could be achieved. The monomer ratio was found to have the greatest effect on the dissolution rate of the PVP-co-VA copolymers. The material with the highest amount of VA (50%) dissolves significantly slower than the other grades. Size-exclusion chromatography (SEC) and Py-GC-MS were used to measure molecular weights and average chemical compositions, respectively. Combined off-line SEC//Py-GC-MS was used to determine the copolymer composition (VP/VA ratio), as a function of the molecular weight for the pure polymers. In the dissolution experiments, a constant VP/VA ratio across the dissolution curve was observed for all copolymers analysed. This suggests a random distribution of the two monomers over the molecules.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Pirrolidinas
/
Compuestos de Vinilo
/
Cromatografía de Gases y Espectrometría de Masas
Idioma:
En
Revista:
Anal Chim Acta
Año:
2011
Tipo del documento:
Article
País de afiliación:
Países Bajos
Pais de publicación:
Países Bajos