Nalazite se na CroRIS probnoj okolini. Ovdje evidentirani podaci neće biti pohranjeni u Informacijskom sustavu znanosti RH. Ako je ovo greška, CroRIS produkcijskoj okolini moguće je pristupi putem poveznice www.croris.hr
izvor podataka: crosbi

Investigation of Upper Liquid-liquid Transition in Unsaturated Polxesters by Near Infrared Spectroscopy (CROSBI ID 90796)

Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija

Pucić, Irina ; Ranogajec, Franjo Investigation of Upper Liquid-liquid Transition in Unsaturated Polxesters by Near Infrared Spectroscopy // Macromolecular chemistry and physics, 202 (2001), 9; 1844-1854

Podaci o odgovornosti

Pucić, Irina ; Ranogajec, Franjo

engleski

Investigation of Upper Liquid-liquid Transition in Unsaturated Polxesters by Near Infrared Spectroscopy

Near infrared spectroscopy was used to investigate less familiar transition in amorphous polymer melts - upper liquid-liquid transition. This transition is related to lower liquid-liquid transition, both are caused by stepwise decrease of local order based on secondary valent interactions that remain above glass transition temperature and has been recently detected in number of polymers. If hydrogen bonding is possible in a polymer, as it is the case in the unsaturated polyesters under consideration, it may enhance the short-range order. The NIR spectroscopy was chosen as a method of investigation because it is sensitive to structural changes, distinction between hydrogen bonded and non bonded hydroxyl groups is easier and thicker samples can be used than in MID region what is very important when concentration of measured species is low. The spectra of poly(1, 3-propyleneglycol-maleate) with styrene and poly(1, 6-hexanediol-maleate) were recorded at selected temperatures. Significant intensity changes of hydroxyl and carbonyl absorptions at 1430 nm and between 1900 nm and 2100 nm accompanied by wavelength shifts occurred at upper liquid-liquid transition temperature while carbon-hydrogen absorptions showed only minor changes. That confirmed our assumption that the upper liquid-liquid transition was caused by changes in hydrogen bonding.

upper liquid-liquid transitions; unsaturated polyesters; hydrogen bonding; local order; near-infrared spectroscopy

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

Podaci o izdanju

202 (9)

2001.

1844-1854

objavljeno

1022-1352

Povezanost rada

Kemija

Indeksiranost