Thomas Midgley

Natural and Synthetic Rubber. XVIII. The Protein from Natural Rubber and Its Amino Acid Constituents

Abstract The protein constituent of rubber has been extracted from the natural rubber by removal of the rubber hydrocarbon with solvents followed by electrodialysis of the residue. This material has been analyzed, subjected to hydrolysis, and its amino acid constituents have been separated and identified.

Natural and Synthetic Rubber. XVI. The Structure of Polystyrene

Abstract Styrene treated with sodium and alcohol gives 75% of ethylbenzene and 25% of 1,4-diphenylbutane. This shows that polystyrene should be represented by formula II, in opposition to the heretofore accepted formula I. Only formula II is consistent with Macks explanation of the rubber-like elastic properties of polystyrene.

Natural and Synthetic Rubber. XII. Reversible Vulcanization, by Organo-Metallic Derivatives

Abstract Rubber has been vulcanized with organo-metallic compounds; this vulcanization has been reversed, then repeated. An interpretation of the experiments is proposed and the bearing on sulfur vulcanization is pointed out.

Natural and Synthetic Rubber. IX. The Products of Destructive Distillation of Ebonite

Abstract The following compounds have been identified in the products obtained from ebonite by destructive distillation: 2-methylthiophene, 2,3-dimethylthiophene, 2,4-dimethylthiophene, 2,5-methylethylthiophene and m-xylene. These results will be used to derive the structural formula of ebonite.

Natural and Synthetic Rubber. IV. 4-Methyl-4-Octene by Isoprene Ethylation

Abstract Isoprene has been ethylated; 4-methyl-4-octene was formed exclusively. The structure of this nonene is in agreement with the usual behavior of a conjugated double bond system. This type of addition is further evidence in favor of the hypothesis which regards the polymerization of isoprene to synthetic rubber as the formation of long chains of isoprene units linked together- by ordinary valences in the 1,4-position.

Natural and Synthetic Rubber. V. Tetramethyloctadiene

Abstract Dimethylbutadiene treated with potassium and alcohol gives 2,3,6,7-tetramethyl-2,6-octadiene and methyl-rubber. The structure of the first hydrocarbon has been established, and is used as an evidence that the methyl-rubber formula must be a long, open chain. This is also regarded as an evidence in favor of the chain formula of natural rubber.