FIG. 1. Effect of irradiation on heat-resistant (120° C) properties of poly- FIG. 2. Elastic properties of irradiated poly- 
ethylene. Control sample at left; shortly-irradiated sample at right ethylene at 150° C. Top rod had received 
0.6 units irradiation; middle rod, 3 units; bot- 
tom rod, 12 units 
How Radiation Affects 
Long-Chain Polymers 
Data showing effects of radiation-induced crosslinking or degradation of 
plastics indicate that the effects can be used in polymer research and for 
industrial processes. Rough cost estimates define commercial feasibility 
BY A. CHARLESBY 
Atomic Energy Research Establishment 
Harwell, England 
FIG. 3. Transformation of polyethylene from a melting to a non-melting polymer at 190° C. Samples held at temperature for 114 hours. 
From left to right, samples received 0, 0.04, 0.05, 0.09, and 0.14 units of radiation 
169 
