No abstract

The copolymerization of itaconic anhydride and styrene has been studied and the r1‐r2 values determined. In benzene r1 = 0.78, r2 = 0.015; in tetrahydrofuran r1 0.60, = r2, 0.10. One possible explanation of the definite positive deviation from constant values in the different solvents has been advanced; it is based on the fact that the copolymer precipitates from benzene as formed. In all cases the r1, r2 product is in the order of 0.01 to 0.06 and indicates that the copolymer is highly alternating in structure. Excellent agreement has been obtained between values of copolymer compositions by analysis and values predicted by copolymer theory based on the copolymer equation. Copolymers of molecular weights in the order of 50,000 to 150,000 (determined by light scattering) were prepared. The rate of copolymerization was about twenty times faster in benzene than in tetrahydrofuran.

The relative densities of solutions of methyl alcohol and toluene have been measured over the entire concentration range at -21.1, 0.0, 25.0 and 49.7°.The volume changes attending mutual solution of the two liquids have been calculated from these densities and the volume changes at a temperature near the boiling point have been estimated by extrapolation.-Suggestions have been offered as to the nature of the association, dissociation and solvation effects which may be responsible for the observed behavior.

In continuation and extension of previous work from this laboratory (1), the following tertiary dimethylamyl carbinols, viz: 2-methylheptanol-2 (2), 2,3-dimethylhexanol-2 (3), 2,4-dimethylhexanol-2 (4, 5), 2,5-dimethylhexanol-2 (6), 2-methyl-3-ethylpentanol-2 (7), 2,3,3-trimethylpentanol-2 (8), 2,3,4-trimethylpentanol-2 (9), and 2,4,4-trimethylpentanol-2 (10) were prepared and condensed with benzene.The resulting alkyl benzenes were separated from the reaction-mixtures by repeated fractionation under reduced pressure. Physical constants were determined. In cases where sufficient quantity of the alkylated product was available, it was nitrated, reduced, diazotized, and hydrolyzed to the corresponding phenol (9). In some cases, the monoacetamino derivative (11), was prepared.The alcohols were prepared as reported in a previous communication (9) with these exceptions. Some of the 2-methyl-3-ethylpentanol-2 was prepared by a modification of the Whitmore (12) procedure, by reacting the Grignard reagent of 3-bromopentane with acetyl chloride, treating the ketone with methylmagnesium bromide and finally hydrolyzing to give the tertiary alcohol; yield, 11%. A part of the 2,4,4-trimethylpentanol-2 was prepared by oxidation of di-isobutylene (13) to 2,2-dimethylpentanone-4 and subsequent reaction of this ketone with methylmagnesium bromide. This method gave a 22% yield of the carbinol based on diisobutylene. The method of Butlerow (10) gave a 46% yield based on diisobutylene. The physical constants of the alcohols were carefully determined and are included in summary in Table I.

A useful method, more rapid and more accurate than elemental analysis, has been developed to determine the composition of copolymers of itaconic anhydride and maleic anhydride with styrene. The method involves a high frequency titration of the sample. The method can also be used to detect traces of acidic impurities in polymers and in the identification of mixtures of similar acidic copolymers. Titration indicates that the acid segments in the copolymers of itaconic acid–styrene, maleic acid–styrene, and the homopolymer polyitaconic acid act as dibasic acids. The method appears to have a sensitivity that permits identification and approximate resolution of two carboxylate species in the same polymer.