## Abstract Rapid heating in a microwave oven has unexpected effects on free radical miniemulsion polymerization: After a temperature pulse of less than 20 s, ultraβhigh molecular weight polystyrene was yielded at a conversion larger than 40%. These results may be explained with the model of βsurvi
Critical Evaluation of the Microwave Effect on Radical (Co)Polymerizations
β Scribed by Yungwan Kwak; Robert T. Mathers; Krzysztof Matyjaszewski
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 613 KB
- Volume
- 33
- Category
- Article
- ISSN
- 1022-1336
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β¦ Synopsis
Abstract
Critical evaluations of the microwave effect on initiation, propagation, and termination during conventional radical polymerizations (RPs) of methyl methacrylate (MMA) and random copolymerization of styrene (St) with (meth)acrylates are examined by comparing microwave heating (MWH) and conventional heating (CH). Poly(methyl methacrylate) with similar $ \overline M_{\rm n} $, $ \overline M_{\rm w} $/$ \overline M_{\rm n} $, and conversion are obtained under precisely controlled temperature, indicating very small changes of propagation rate constant. Rate enhancement in the absence of precise temperature control is mostly due to the higher reaction temperature of the reaction mixture than the apparent value indicated on display. Rates of initiator decomposition under wellβcontrolled temperature are essentially the same for MWH and CH.
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