Investigation of Hydrogen Bonded Interpolymer Complexes Based on Poly (n-butyl methacrylate-co-methacrylic acid) and Poly (n-butyl methacrylate -co-4-vinyl pyridine). Temperature Effect

• Published in: Macromolecular symposia. 2011-05, Vol.303 (1), p.26-36
• Main Authors: Metref, Farid, Djadoun, Said
• Format: Article
• Language: English
• Subjects: Blends; Copolymers; Density; FTIR; Hydrogen bonding; interpolymer complexes; Monitoring; poly (butyl methacrylate-co-methacrylic acid); poly (butylmethacrylate-co-4-vinyl pyridine); Precipitates; Precipitation; Pyridines; viscometry
• ISSN: 1022-1360; 1521-3900; 1521-3900
• DOI: 10.1002/masy.201150504

Two kinds of interpolymer complexes as soluble or precipitate of different structures were obtained in both THF and butan‐2‐one as common solvents by monitoring the hydrogen‐bonding density within homoblends of poly(n‐butyl methacrylate‐co‐4‐vinylpyridine) (BM4VP) and poly(n‐butyl methacrylate‐co‐methacrylic acid) (BMMA). A viscometry study confirmed such differences between these two types of interpolymer complexes from the behavior of the reduced viscosity of their blend solutions with feed blend composition. Qualitative and quantitative analyses of the interactions that occurred between these copolymers of relatively bulky side chain length containing various amounts of methacrylic acid and 4‐vinylpyridine were carried out by FTIR. The fraction of associated pyridine groups to the carboxylic groups of the BMMA increases as the content of these latter increases in the BMMA/BM4VP blends. The obtained results also showed that the fractions of associated pyridine within the BMMA25/BM4VP26 blends are higher than those within BMMA18/BM4VP19 or BMMA8/BM4VP10. The FTIR analysis of a selected BMMA18/BM4VP19 1:1 ratio, carried out from 80 °C to 160 °C, above the glass transition temperatures of the two constituents of the blend, confirms the presence of strong hydrogen bonding interactions between the pyridine and the carboxylic groups within these blends even at 160 °C. A LCST is expected to occur at higher temperature as shown from the progressive decrease of the fraction of the associated pyridine.