EFFECT OF PILE IRRADIATION ON THE DYNAMIC MECHANICAL PROPERTIES OF POLYETHYLENE

Journal Article · Sat Feb 01 04:00:00 EST 1958 · J. Polymer Sci.

DOI:https://doi.org/10.1002/pol.1958.1202811610· OSTI ID:4307041

Deeley, C W; Kline, D E; Sauer, J A; Woodward, A E

The affects of pile irradiation on the damping and resonant frequency of a high pressure'' polyethylene were investigated over a temperature range from 80 to 550 deg K in the audiofrequency region using an apparatus which drives rod- like specimens in their transverse modes. Using irradiation dosages which result in approximately 4% cross-linking or greater, the mechanical loss peaks found at about 166, 265, and 355 deg K in polyethylene are altered. Definite changes in the resonant frequency or modulus-temperature plots also occur. The 355 deg K peak, attributed to the melting of the crystalline portions of the sample, decreases in height and shifts to lower temperatures with increasing irradiation dose. A decrease in the height of the 265 deg K peak accompanied by a shift to higher temperatures takes place. The 165 deg K peak initially increases in height and peak temperature but at higher dosages a marked decrease in the damping maximum occurs. The damping behavior in the 165 and 265 deg K regions is discussed in terms of diffusional motion of chain segments in the amorphous polymer portions. (auth) The usefulness of the biological thermal column of the Brookhaven Reactor in carrying studies of the effect of scavenging agents on radiation chemical reactions produced by very densely ionizing radiations has been demonstrated. It has been shown that a 10% increase in the yield for oxidation of ferrous ion by the recoil radiations from the B/sup 10/(n, alpha )Li/ sup 7/ reaction accompanies an increase in ferrous sulfate concentration from 0.26 to 10 mM. This is in contraet to the negligible change in yield observed over this same concentration region for reactions produced by gamma -radiation. These studies further stress the importance of scavenging processes in the case of densely ionizing radiations. (auth)

• Research Organization: Pennsylvania State Univ., University Park
• NSA Number: NSA-12-010460
• OSTI ID: 4307041
• Journal Information: J. Polymer Sci., Journal Name: J. Polymer Sci. Vol. Vol: 28
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHEMISTRY
CRYSTALS
DAMPING
INSTRUMENTS
MECHANICAL PROPERTIES
MELTING
POLYETHYLENES
PRESSURE
QUANTITY RATIO
RADIATION DOSES
RADIATION EFFECTS
REACTORS
RODS
TEMPERATURE