Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
VISCOSITY OF ETHYLENE TETRAFLUOROETHYLENE ALTERNATING COPOLYMERS
Autore:
KUNG LL; CHU B;
Indirizzi:
SUNY STONY BROOK,DEPT CHEM STONY BROOK NY 11794 SUNY STONY BROOK,DEPT CHEM STONY BROOK NY 11794 SUNY STONY BROOK,DEPT MAT SCI & ENGN STONY BROOK NY 11794
Titolo Testata:
Polymer
fascicolo: 11, volume: 36, anno: 1995,
pagine: 2265 - 2269
SICI:
0032-3861(1995)36:11<2265:VOETAC>2.0.ZU;2-#
Fonte:
ISI
Lingua:
ENG
Soggetto:
LIGHT-SCATTERING CHARACTERIZATION; HIGH-PRESSURE; VISCOMETER; CELL;
Keywords:
LOW SHEAR RATE VISCOSITY; MOLECULAR WEIGHT; ACTIVATION ENERGY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
25
Recensione:
Indirizzi per estratti:
Citazione:
L.L. Kung e B. Chu, "VISCOSITY OF ETHYLENE TETRAFLUOROETHYLENE ALTERNATING COPOLYMERS", Polymer, 36(11), 1995, pp. 2265-2269

Abstract

Low shear rate viscosity measurements of alternating copolymers of ethylene and tetrafluoroethylene (PETFE) melts have been performed at different temperatures by using the centrifuge ball viscometer. The viscosity eta (Pa s) could be obtained with an empirical relation, a(c) = (4.29 +/- 0.08) x 10(2)(eta V-proportional to)(0.856 +/- 0.004) , Witha(c) and V-proportional to being, respectively, the acceleration (g =9.8 m s(-2)) and the terminal velocity (m s(-1)) of a stainless steelball of 1.58 mm diameter moving in the polymer melt, which was flame sealed in a horizontal cylindrical glass tube of 4.26 mm diameter. Forthe temperature dependence of the viscosity, an activation energy E(a) of 15.3 kcal mol(-1) was determined. The activation energy for PETFEis between 5.7-14.6 kcal mol(-1) for polyethylene (PE) and 18-36 kcalmol(-1) for tetrafluoroethylene (PTFE). A relationship between the zero shear rate viscosity eta(0) (Pa s) and the molecular weight M(w) (gmol(-1)) of PETFE copolymer melts at 280 degrees C [eta(0) = (1.23 +/- 0.02) x 10(-16)(M(w))(3.43 +/- 0.06)] should permit us to determine the molecular weight of PETFE with the centrifuge ball viscometer.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 21:12:23