Accession Number : AD0015175

Title :   POLYTETRAFLUOROETHYLENE: POLYMERIZATION, STRUCTURAL CONTAMINANTS AND THERMAL STABILITY

Corporate Author : NATIONAL BUREAU OF STANDARDS BOULDER CO

Personal Author(s) : FLORIN, R.E. ; WALL, L.A.

Report Date : 15 JUL 1953

Pagination or Media Count : 18

Abstract : Various conditions and catalysts were utilized in an effort to increase the thermal stability of polymers. Materials were added to polymers which might enter as structural units or be intimately incorporated in the polymer mass. The degradation of the resulting polymer was studied, and rates were compared. The polymerization of C2F4 is believed to be similar to that of most vinyl monomers and appears to proceed by a free-radical mechanism. Most of the monomer was prepared by the pyrolysis of Teflon at 650-700 deg C and 1 mm; a small lot was prepared by the pyrolysis of CF3CF2CO2Na. The polymerizations were accomplished in sealed tubes in a cold block which allowed the samples to be held at a low temperature while exposed to ultraviolet irradiation. The catalysts additions, conditions, and conversions to polymers are tabulated. Many polymerizations proceeded at -80 deg C. The photopolymerization of C2F4 appeared to proceed at a low rate. Catalytic activity with (CF3)2Hg was studied in the presence and absence of light. The sample stored in the dark showed the highest conversion.

Descriptors :   , ADDITION, CATALYSTS, CONVERSION, DEGRADATION, FREE RADICALS, IRRADIATION, LOW RATE, LOW TEMPERATURE, MASS, MONOMERS, POLYMERIZATION, POLYMERS, PYROLYSIS, STRUCTURAL PROPERTIES, TETRAFLUOROETHYLENE RESINS, THERMAL STABILITY, ULTRAVIOLET RADIATION, VINYL RADICALS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE