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US4136084A
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Molecular-weight modification of polyphosphazenes
Assignee: Armstrong World Industries Inc
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Filing: 1978-01-05
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Granted: 1979-01-23
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Expires: 1998-01-05
Abstract
Abstract A novel process has been developed for the molecular-weight modification of polyphosphazenes. Poly(aryloxyphosphazenes) are thermally treated in an inert atmosphere or vacuum at temperatures from 100° C. to 300° C. so as to yield materials having reduced molecular weights, improved processability, and enhanced thermal stability.
Inventors
- 👤 Ronald L. Dieck
- 👤 Louis Goldfarb
- 👤 Nancy D. Hann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:12
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08G; C08G79/00; C08G79/02; C08G79/025; C08L; C08L85/00; C08L85/02; C08J2385/00; C08J2385/02; Y; Y10; Y10S; Y10S521/00; Y10S521/903
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
99 words
A process for substantially reducing the molecular weight of a curable poly(aryloxyphosphazene) polymer having randomly distributed repeating units of the formula ##STR4## wherein R 1 and R 2 are the same or different and represent hydrogen, C 1 -C 10 linear or branched alkyl, C 1 -C 4 linear or branched alkoxy, which process comprises heating said polymer to a temperature of from about 100° to about 300° C., in the absence of air or oxygen, for a period of at least 15 minutes, to produce a poly(aryloxyphosphazene) polymer having a reduced molecular weight and being uncrosslinked and uncured.
Claim 2
Dependent Claim
99 words
A process for substantially reducing the molecular weight of a curable poly(aryloxyphosphazene) polymer having randomly distributed repeating units of the formula ##STR4## wherein R 1 and R 2 are the same or different and represent hydrogen, C 1 -C 10 linear or branched alkyl, C 1 -C 4 linear or branched alkoxy, which process comprises heating said polymer to a temperature of from about 100° to about 300° C., in the absence of air or oxygen, for a period of at least 15 minutes, to produce a poly(aryloxyphosphazene) polymer having a reduced molecular weight and being uncrosslinked and uncured.
Claim 3
Dependent Claim
36 words
The process of claim 1 wherein when R 1 and R 2 are different, the (OC 6 H 4 --R 1 ):(OC 6 H 4 --R 2 ) ratio is from about 1:6 to about 6:1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-22 | 1982-07-24 | 1983-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-22 | 1986-07-24 | 1987-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-22 | 1990-07-24 | 1991-01-23 | $7700.00 | Window Closed / Lapsed |