ISSN:
0449-2978
Schlagwort(e):
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Three transitions are detected dilatometrically when partially isotactic poly(propylene oxide) melts. One transition, the temperature of which is independent of the crystallization temperature over a wide range below 60°C, is ascribed to the melting of lamellar crystallites which are limited in thickness by the average isotactic sequence length alone. The other two transitions, the temperatures of which vary with the crystallization temperature, are ascribed to the melting of lamellar crystallites with thickness determined predominantly by three- and two-dimensional primary nucleation acts. The theory of Flory is adapted and applied quantitatively to the melting points of three crystalline fractions of poly(propylene oxide), obtained from a polymer produced via the zinc diethyl and water catalyst system. This method leads to a thermodynamic melting point of isotactic poly(propylene oxide) near 82°C.
Zusätzliches Material:
3 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1970.160080404
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