Marlex 6003, Phillips irradiation

Figure 5. Carbon-13 NMR Spectrum of Phillips Marlex 6003 Irradiated in the Solid State.

Phillips Marlex 6003, a high density polyethylene (Mw = 53,000 Mp = 18,000) possessing predominantly saturated end groups was irradiated to 4.0 Mrad in vacuum in pellet form as supplied. NBS 1475 is a commercial polyethylene containing 111 ppm of Irganox 1010. Other experiments involved heating in vacuum to 500 K for 24 h prior to irradiation to 3.0 Mrad at 500 K. The NBS 1475 sample required a greater amount of irradiation to reach the gel dose than did Marlex 6003. 

Irradiation of Marlex 6003 Polyethylene. Results of 13c NMR measurements on Phillips Marlex 6003 polyethylene both prior to and just following a 2.0 Mrad irradiation in vacuum and 298 K are presented in Table IV. The spectra from which these data were obtained are shown in Figures 4 and 5. These results indicate that irradiation of high density polyethylene in vacuum in the solid state reduces the concentration of terminal vinyl unsaturations and increases the concentrations of long chain Y branches, saturated end groups and trans double bonds. The H-link could not be detected following an irradiation of Marlex 6003 in the solid state. 

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