Molecular composites, in which a small concentration of ionically modified poly(p-phenylene terephthalamide) (PPTA) is dispersed in a poly(ethylene oxide) matrix, have been prepared. With the content of PPTA anion increasing to about 5 wt %, the glass-transition temperature rises and the melting tem
Molecular composites of poly(p-phenylene terephthalamide) anion and poly(ethylene oxide): Mechanical properties
โ Scribed by L. Tsou; J. A. Sauer; M. Hara
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 339 KB
- Volume
- 38
- Category
- Article
- ISSN
- 0887-6266
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โฆ Synopsis
Molecular composites were prepared by the solution blending of poly(ethylene oxide) (PEO) of three different molecular weights with low concentrations of poly(p-phenylene terephthalamide) (PPTA) anion serving as a rigid-rod reinforcement. For all of the composites, the tensile strength, stiffness, and fracture energy were enhanced relative to values for the three PEO homopolymers. Composites made with PEO of high molecular weight (ฯณ10 6 or higher) exhibited good extensibility and improved resistance to stress relaxation and attained maximum values of strength and toughness at a PPTA-anion content of about 6 wt %. The enhancement in mechanical properties is primarily attributed to good miscibility between the components arising from the presence of intermolecular, ion-dipole interactions between the ionic units of the PPTA anion and the dipole units of the PEO. Some consideration is also given to possible effects of a nucleating agent and an annealing treatment, both of which lead to additional increases in the tensile strength of the composites.
๐ SIMILAR VOLUMES
Molecular composites have been prepared by dispersing rigid-rod molecules of ionically-modified poly(p-phenylene terephthalamide) (PPTA anion) in a polar poly(4vinylpyridine) (PVP) matrix. For concentrations up to 5 wt % of the rigid-rod reinforcement, the resulting composites are transparent and po
This article describes the rheological properties of certain poly(ethylene oxide)s dissolved in water-based solvents. The experimental results show that the rheological properties in aqueous solutions are significantly affected by the solvent properties, which have been changed by the use of ethanol