Charles Givhan Johnson
Dentist in Hot Springs, AR
License number
Colorado 104222
Issued Date
Sep 19, 1977
Renew Date
Mar 1, 2004
Expiration Date
Feb 28, 2006
Type
Dentist
Address
Address
600 X Main St, Hot Springs, AR 71913
Professional information
Dr. Charles G Johnson, Hot Springs AR - DMD (Doctor of Dental Medicine)
Specialties:
Pediatric Dentistry
Address:
600 Main St, Hot Springs 71913
(501) 624-4421 (Phone), (501) 624-6727 (Fax)
(501) 624-4421 (Phone), (501) 624-6727 (Fax)
Languages:
English
Process For Preparing And Purifying Alkoxyphosphazene Polymer
US Patent:
4609724, Sep 2, 1986
Filed:
Apr 29, 1985
Appl. No.:
6/730410
Inventors:
Robert A. Elefritz - Ordmond Beach FL
William M. Cole - Norton OH
Charles R. Johnson - Hot Springs Village AR
William M. Cole - Norton OH
Charles R. Johnson - Hot Springs Village AR
Assignee:
The Firestone Tire & Rubber Company - Akron OH
International Classification:
C08G 7904
US Classification:
528399
Abstract:
Alkoxyphosphazene polymer is prepared in a homogeneous system by admixing chloropolymer dissolved in cyclohexane or a mix of cyclohexane and C. sub. 5 -C. sub. 7 alkane with alkali metal alkoxide dissolved in tetrahydrofuran, reacting, desalting the resulting reaction solution and concentrating by a first step involving admixing non-solvent which is cyclohexane (and/or C. sub. 5 -C. sub. 7 alkane if that is also present in the reaction solution) to cause coagulation thereby forming a higher viscosity rubber phase enriched in polymer and a lower viscosity liquid phase depleted in polymer and separating the rubber and liquid phases and a second step involving evaporating the residual solvent and non-solvent. The first concentrating step is preferably carried out utilizing an extruder.