Portal de Periódicos da CAPES

Radikalpolymerisation von methylmethacrylat im gesamten umsatzbereich. Stationäre und instationäre experimente zur bestimmung von wachstums‐ und abbruchsgeschwindigkeit

1989; Wiley; Volume: 190; Issue: 5 Linguagem: Inglês

10.1002/macp.1989.021900520

0025-116X

Regina Sack‐Kouloumbris, Günther Meyerhoff,

Epoxy Resin Curing Processes

Abstract Free‐radical polymerization of methyl methacrylate in bulk at 0°C over the full range of conversion is reported. Details for stationary and non‐stationary experiments are described allowing to measure both kinetically relevant ratios fk / k a and k w / k a , f representing radical efficiency, k w rate constants of propagation and k a rate constant of termination. From these ratios the absolute rate constants k w and k a are available. The photochemical decay of the initiator 1,1′‐azodicyclohexanenitrile in connection with the rotating‐sector technique and observation of the post‐effect after stopping the initiator decay were used. The rate of polymerization and the number‐ and weight‐average molar masses were measured. Both, k w and k a , showed a strong dependence on conversion which is well known for k a but is reported here for the first time for k w since Hayden and Melville's determination of k w from measurements of the temperature increase during polymerization were reported.