ISSN:
0021-8995
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
The crystallization and polymerization behavior of a crystalline LaRC-TPI powder at elevated temperatures have been studied. The characterization methods include differential scanning calorimetry and the measurements of inherent viscosity, ηinh, and viscoelastic properties of the fully imidized samples. The as-Received material possesses an initial crystal melting peak temperature of 272°C. For the material annealed at temperatures below 320°C, a semicrystalline polymer can be obtained. On the other hand, a purely amorphous structure is realized in the samples annealed at temperatures above 320°C. Isothermal crystallization kinetics are studied by means of the simple. Avrami equation. The likely nucleation path is attributed as an intermolecular oligomer nucleation type. The isothermal polymerization behavior is quantified by inherent viscosity measurements. A single cure is found to correlate values of Tg and ηinh for samples experiencing different thermal histories. Fully imidized amorphous and semicrystalline LaRC-TPI samples are successfully molded based on the information obtained from thermal analyses. The viscoelastic properties of these samples are also reported.
Zusätzliches Material:
15 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/app.1988.070360206
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