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US 4,377,660 AGranted
Molded polymer treatment
AssigneePhillips Petroleum Company
InventorsVan C. Vives, Donnie G. Brady
Life of this patent
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Abstract
The physical and chemical properties of arylene sulfide polymer articles are improved by contacting with a strong oxidizing agent followed by a step-wise heat treatment at temperatures below the melting point of the polymer.
Claims9
A process for improving the physical and chemical properties of arylene sulfide polymers which comprises
- (a) contacting a surface of a molded form of said polymer with an alkali metal or alkaline earth metal hypohalite and
- (b) subjecting the polymer of (a) to heat treatment at a temperature below the melting point of the polymer in plural stages of increasing temperatures with the initial stage being carried out at about 475.degree. F. and heating at each stage being maintained for a period of time sufficient to improve the flexural and tensile properties of the molded polymer and extend the limits of its usage to higher temperatures.
Dependencies are inferred from the claim text.