ISSN:
0022-3832
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
The polymerization of ethylene initiated by 2,2,-azobisisobutyronitrile in water was studied at 70-120° C. and at 100-1500 kg./cm.2 pressure. The following relations between the reaction conditions and the properties of polyethylene produced were obtained (1) the density decreases with temperature, and (2) the molecular weight increases with pressure, independent of the amount of initiator. The reaction begins with an incubation period for which the overall rate Ri is represented by Ri = const. × I0P0, in which I0 and P0 are the amount of initiator used and the initial pressure, respectively. In the main period of reaction the overall rate was found to be R = k′I0 exp {-αt}P1.8. A reaction mechanism is proposed from which this rate equation can be derived. The proposed mechanism implies that the deactivation and the termination of radicals is first order with respect to the radical concentration.
Zusätzliches Material:
7 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1959.1204113807
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