Radical Copolymerization of Butadiene with Acrylonitrile in Emulsion

Radical Copolymerization of Butadiene with Acrylonitrile in Emulsion 

Safety precautions Befote this experiment is carried out. Sect. 2.2.5 must be read as well as the material safety data sheets (MSDS) for all chemicals and products used. 

Monomeric acrylonitrile is distilled under nitrogen into a suitable receiver (see Sect. 2.2.S.3). Butadiene from a cylinder is condensed under nitrogen atmosphere into a trap cooled in a methanol/dry ice bath. 

Copolymers of butadiene and acrylonitrile are soluble in aromatic or chiorinated hydrocarbons but insoiubie in aiiphatic hydrocarbons.Therefore they find use in oil-resistant rubber articles (hoses, sealings etc.) 

Preparation of a Styrene/Butyl Acrylate/Methacrylic Acid Terpolymer Dispersion (Influence of Emulsifier) 

As described in Example 3.44, a mixture of 10 g (0.19 mol) of acrylonitrile containing 0.1 g dodecylmercaptane as regulator and 25 g (0.46 mol) of butadiene is polymerized in 50 ml of a 5% aqueous solution of sodium oleate (or sodium dodecyl sulfate) containing 0.25 g (0.93 mmol) of potassium peroxodisulfate as initiator. After 18 h the pressure bottle is allowed to cool to room temperature and is finally cooled in ice. It is now weighed again to confirm that no butadiene has been lost by leakage. The bottle is carefully opened, the latex poured into a beaker and 

5 g of A/ -phenyl- (3-naphthylamine stirred in as antioxidant. A soluticai of 5 wt% of sodium chloride in 2% sulfuric acid is now added dropwise with stirring until the copolymer flocculates. It is filtered off, stirred vigorously with water several times in a beaker, filtered again and dried in vacuum at 65-70°C. The composition of the copolymer is determined from the nitrogen content determined according to the Kjeldahl method or from the double bond content. The arrangement of the butadiene monomeric units is found by IR spectroscopy (see Example 3.21). 

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Example 3.45 Radical Copolymerization of Butadiene with Acrylonitrile in Emulsion... 

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