ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The volume flow of isotactic polypropylene (i-PP) with number-average molecular weight M̄n = 103 200, melting temperature Tm = 426 K and glass transition temperature Tg = 238 K, has been measured. The elastic modulus of the longitudinal wave, longitudinal volume viscosity, initial longitudinal volume viscosity, and retardation times, are described for compression rates between ca. 1,0·10-5 and 200,0·10-5 s-1, and at temperatures between 443 K and 473 K as well as pressures up to 150 MPa at which no sign of crystallization was detected. The longitudinal volume viscosity decreases with increasing compression rate and with decreasing volume deformation, the behaviour being in all cases a typical non-equilibrium one. The longitudinal volume viscosity increases with increasing temperature, the volume flow activation energy being about 78,08 kJ/mol.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1988.021890311
