Effect of annealing on the structure of quenched isotactic polypropylene
- 2 September 1989
- journal article
- research article
- Published by Taylor & Francis Ltd in Journal of Macromolecular Science, Part B
- Vol. 28 (3-4), 489-502
- https://doi.org/10.1080/00222348908215238
Abstract
Smectic isotactic polypropylene films were annealed at different temperatures for different times. Density, wide-angle x-ray scattering (WAXS), differential scanning calorimetry, and the transport properties of methylene chloride vapor were used to follow the transformation of the smectic phase into the monoclinic phase. The results of WAXS diffractograms indicate different saturation levels of crystallization with the maximum order attained progressively more quickly at higher temperatures. Density measurements, however, show that, after a first saturation level, a further increase of this parameter occurs after long annealing times; and this second step is lower, the higher the temperature. Sorption and diffusion, analyzed to investigate the amorphous component, show that annealing the smectic phase at 50°C results in a decrease of amorphous fraction without transformation of the smectic phase. The transition from smectic to monoclinic phase occurs at temperatures higher than 60°C. During the annealing at 80°C there is first a decrease of amorphous fraction corresponding to the first saturation level of the density, and then a further decrease of amorphouse phase corresponding to the final increase of density after 24 hr of annealing.Keywords
This publication has 10 references indexed in Scilit:
- Structure and aging behavior of lsotactic polypropylene films quenched at room temperatureJournal of Macromolecular Science, Part B, 1989
- Crystallization of oriented smectic polypropylene I. Thermally induced crystallizationColloid and Polymer Science, 1988
- Structure and properties of polypropylene crystallized from the glassy stateJournal of Polymer Science Part B: Polymer Physics, 1986
- Effect of quenching temperature on the structure of isotactic polypropylene filmsJournal of Macromolecular Science, Part B, 1986
- Investigation of the structure of isotactic polypropylene via transport propertiesJournal of Polymer Science Part B: Polymer Physics, 1986
- The thermal properties of polypropyleneJournal of Polymer Science: Polymer Symposia, 1984
- Some crystallization kinetics of isotactic polypropylenePolymer, 1981
- Non‐newtonian intrinsic viscosity and streaming birefringence of polymer solutionsJournal of Polymer Science Part C: Polymer Symposia, 1967
- Structure and properties of isotactic polypropyleneIl Nuovo Cimento (1869-1876), 1960
- On the existence of near-range order in isotactic polypropylenesPolymer, 1960