EFFECTS OF HIGH ENERGY IRRADIATION ON POLYPROPYLENE

Journal Article · Sun Sep 01 04:00:00 EDT 1963 · J. Polymer Sci., Pt. A

DOI:https://doi.org/10.1002/pol.1963.100010905· OSTI ID:4669227

Chappell, S E; Sauer, J A; Woodward, A E

Isotactic polypropylene (Profax) film samples irradiated in the Pennsylvania State University reactor at ambient temperatures were examined by solvent extraction and infrared absorption techniques. At low irradiation doses, samples annealed (density = 0.909 g/cc at 24 deg C) prior to irradiation were found to have a lower gel content and a hlgher concentration of oxidation products than quenched samples (density = 0.899 g/cc at 24 deg C) irradiated under identical conditions. Similar gel fraction results were obtained for electron irradiated samples of polypropylene. The effects are believed to arise from the accumulation of a greater concentration of free macroradicals in the higher density samples. At hlgher reactor dosages the irradiation effects in the annealed and quenched films appeared to be about the game. The gel content as a function of dose was found to be independent of the irradiation intensity level over a twofold range. Irradiations were also carried out on high density polyethylene (Marlex 50) pellets at two temperatures, viz, 40 plus or minus 10 deg C and 150 deg C. Irradiation at 150 deg C led to a greater gel content at any given dose. Nuclear magnetic resonance spectra were obtained for molded annealed samples of partially isotactic polypropylene, irradiated at temperatures of 90 to 330 deg K. The observed shifts in the line narrowing process that occur in the 270 to 530 deg K region are explained in terms of the decrease in crystallinity and the increasing density of crosslinks that accompany irradiation. (P.C.H.)

• Research Organization: Pennsylvania State Univ., University Park
• NSA Number: NSA-17-034014
• OSTI ID: 4669227
• Journal Information: J. Polymer Sci., Pt. A, Journal Name: J. Polymer Sci., Pt. A Vol. Vol: 1
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
ANNEALING
CASTING
CHEMICAL REACTIONS
CHEMISTRY
COLLOIDS
CONFIGURATION
CRYSTALS
DECOMPOSITION
DENSITY
DIAGRAMS
ELECTRON BEAMS
ENRICHMENT
FILMS
FREE RADICALS
HEAT TREATMENTS
INFRARED RADIATION
IRRADIATION
LOW TEMPERATURE
MOLECULES
NUCLEAR MAGNETIC RESONANCE
OXIDATION
PELLETS
PHOTOMETRY
POLYETHYLENES
POLYMERS
POLYPROPYLENE
PROPYLENE
QUANTITY RATIO
QUENCHING
RADIATION CHEMISTRY
RADIATION DOSES
RADIATION EFFECTS
RADIATION SOURCES
RADIOLYSIS
REACTORS
SAMPLING
SOLVENT EXTRACTION
SPECTRA
SPECTRAL SHIFT
SPECTROSCOPY
TEMPERATURE