ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The radiation crosslinking (via Co60) of both high and low density polyethylene in the presence of several tetrafunctional monomers has been studied to observe the effects of the additives on mechanical and electrical properties. The monomers employed were allyl methacrylate, divinylbenzene, and diallyl maleate. Monomer levels were such that the number of moles presented per number-average mole of polyethylene was 2.2-2.6 for AMA and DVB with Marlex 5003 and 6009, and 9-10 for Marlex 1712. The DAM level was 3-5% of that of the other monomers on the same basis. Gel fractions, tensile strengths (at yield and break) at ambient temperature and tensile strengths, elongations, and moduli measured at a temperature above which no crystallinity remains all undergo more marked changes in the presence of tetrafunctional monomer after only 1-3 Mrad of radiation, regardless of monomer nature. Gels, tensiles, and moduli increase while elongation decreases. The magnitude of the changes depends upon the monomer nature (at the above ratios), the order being AMA〉DVB〉DAM〉 Monomer-free. With increasing does to 8 Mrad, the trends continue. The gel swelling ratios are inversely proportional to the 3/5 power of the crosslink density, as determined by the modulus value in the absence of crystallinity. Straight radiation of monomer-free polyethylene to higher doses not necessarily yield physical properties values attained at the lower doses with additive. The dielectric constant and dissipation factor of monomer-containing crosslinked polyethylene are only slightly affected by the presence of the polyfunctional monomer.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1966.070100111
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