ISSN:
0003-3146
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Description / Table of Contents:
Es wurde die Kinetik der Polymerisation von Methylmethacrylat in verdünntem salpetersaurem Medium bei 40°C mit einem Dreikomponenteninitiator - Saurestoff-Ascorbinsäure-Fe3+ionen - untersucht. Die Polymerisationsgeschwindigkeit, Rp, erwies sich bei unterschiedlichen experimentellen Bedingungen proportional [MMA]1,5. Rp war unabhängig von der [Fe3+] innerhalb der Konzentrationsreihe 2-5·10-5M, erniedrigte sich aber bei höheren Werten. Rp war auch unabhängig von der [AA] und für [O2] 〈 6,5·10-4M wurde eine Abhängigkeit [O2]0,6 gefunden.
Notes:
The kinetics of polymerization of methyl methacrylate (MMA) in dilute nitric acid medium at 40°C initiated by the three component initiating system, oxygen-ascorbic acid (AA)-ferric ions was investigated. The rate of polymerization, Rp, was found to be proportional to [MMA]1.5 under different experimental conditions. Rp, was independent of [Fe3+] in the concentration range 2 to 5 - 10-5 M, but decreased slightly at higher values. Rp was also independent of [AA] and a dependence on [O2]0.6 was noticed with [O2] 〈 6.5 × 10-4M. After an initial increase, Rp became independent above [HNO3] ≈ 0.3M. Ionic strength, μ, of the medium had no effect on Rp. A rate increase up to 42°C followed by constancy and decrease with further increase in temperature (〉46°C) was noticed. The chain lengths of the polymers were determined to be in the range 102 - 103 by viscometry. A plausible reaction mechanism with initiation by the primary radical and termination by mutual interaction was proposed.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/apmc.1983.051150106
