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Metathesis degradation of polymers obtained by grignard‐wurtz reaction of partially α‐brominated 1,4‐polybutadiene
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Abstract1,4‐Polybutadiene was partially brominated at the methylene groups with N‐bromosuccinimide. Then, by means of Grignard‐Wurtz reactions, the following substituents were introduced: isopropyl, butyl, pentyl, cyclohexyl, phenyl, 4‐methylphenyl, 4‐ethylphenyl, 3,4‐dimethylphenyl, 4‐isopropylphenyl, 4‐fluorophenyl, 3‐trifluorophenylmethyl, 4‐chlorophenyl, benzyl, 2‐methylbenzyl, and 4‐methylbenzyl. The modified polymers (ca. 20% of the units substituted) were degraded to low molecular products with E‐4‐octene in the presence of the catalyst WCl6/(CH3)4Sn. The degradation products were separated by gas chromatography and identified by mass spectrometry. Isomeric substituents, isomeric units, and isomeric segments in the polymers could be distinguished. — In Grignard‐Wurtz reactions, transfer reactions with toluene as solvent and simultaneous reactions with two Grignard reagents (4‐methylphenyl and 4‐methylbenzyl compounds) were also investigated.
Title: Metathesis degradation of polymers obtained by grignard‐wurtz reaction of partially α‐brominated 1,4‐polybutadiene
Description:
Abstract1,4‐Polybutadiene was partially brominated at the methylene groups with N‐bromosuccinimide.
Then, by means of Grignard‐Wurtz reactions, the following substituents were introduced: isopropyl, butyl, pentyl, cyclohexyl, phenyl, 4‐methylphenyl, 4‐ethylphenyl, 3,4‐dimethylphenyl, 4‐isopropylphenyl, 4‐fluorophenyl, 3‐trifluorophenylmethyl, 4‐chlorophenyl, benzyl, 2‐methylbenzyl, and 4‐methylbenzyl.
The modified polymers (ca.
20% of the units substituted) were degraded to low molecular products with E‐4‐octene in the presence of the catalyst WCl6/(CH3)4Sn.
The degradation products were separated by gas chromatography and identified by mass spectrometry.
Isomeric substituents, isomeric units, and isomeric segments in the polymers could be distinguished.
— In Grignard‐Wurtz reactions, transfer reactions with toluene as solvent and simultaneous reactions with two Grignard reagents (4‐methylphenyl and 4‐methylbenzyl compounds) were also investigated.
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