EFFECTS OF MONOMER DIFFUSION ON RADIATION-INDUCED GRAFT COPOLYMERIZATION

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Proc. Japan Conf. Radioisotopes

OSTI ID:4707691

Matsuo, H; Kondo, M

The interferometric method was applied as a direct visualization of the distribution curve of graft concentration of radioinduced graft copolymers. Polypropylene -- styrene (PP-St) and polytetrafluoroethylene-- styrene (PTFE -- St) graft copolymer films were studied. The studies showed the relation between monomer diffusion and the graft reaction and, therefore, the effects of radiation dose and film thickness on the graft composition. The graft copolymer films were prepared by simultaneous gamma irradiation. Since polystyrene has a higher refractive index than PP and PTFE, an interferometer was used to estimate gradients of the refractive index from surface to the center of the specimens by observing the localized interference fringes. The diffusion coefficient of monomer in PP does not depend upon the graft concentration. However, in the case of PTFE, no monomer is able to penetrate into this polymer in the usual way, and therefore the grafting is limited to the surface. The diffusion coefficient of monomer in partially grafted PTFE varies with the graft concentration. Observed distributions of graft concentration of the two polymers show quite different characteristics. The distribution curve for PP-- St graft film is a catenary and the grafting effect extends to the interior of film with the decrease in dose rate. For the PTFE--St graft, the film grafting layer is limited near the surface of the film, although the depth varies with dose rate, standing time after irradiation, benzene concentration in monomer, and temperature. Furthermore, apparent retardative effects on grafting were observed in the vicinity of the surface in both cases. Calculated distributions of graft concentration of the two polymers are in accordance with those observed. The retardative effect on grafting can be interpreted by the fact that tbe grafting rate is variable. The effects of dose rate, film thickness, and monomer concentration are explained. (P.C.H.)

• Research Organization: Nippon Telegraph and Telephone Public Corp.
• NSA Number: NSA-17-030196
• OSTI ID: 4707691
• Journal Information: Proc. Japan Conf. Radioisotopes, Journal Name: Proc. Japan Conf. Radioisotopes Vol. Vol: 5th, No. 4
• Country of Publication: Country unknown/Code not available
• Language: Japanese

Related Subjects

CHEMICAL REACTIONS
DIFFUSION
DISTRIBUTION
ETHYLENE
FILMS
GENERAL AND MISCELLANEOUS
GRAFT POLYMERS
IRRADIATION
LAYERS
OPTICAL SYSTEMS
POLYMERIZATION
POLYMERS
PREPARATION
PROPYLENE
QUANTITY RATIO
RADIATION DOSES
RADIATION EFFECTS
REFRACTION
STYRENE
SURFACES
TEMPERATURE
THICKNESS
VARIATIONS