No abstract

Maleic anhydride has been homopolymerized, contrary to accepted beliefs. Polymerization of either molten or dissolved monomer was initiated with the use of gammaradiation and free‐radical initiators. An anhydride having [η] = 0.146 dl./g. in acetophenone had a molecular weight of 23,100 (free acid), DP = 199, by the light‐scattering method. The carboxyl group propinquity is responsible for peculiar behavior of aqueous solutions of salts of the poly‐acid.

S31tween Flory's and Hermans' equations cannot be made a t this time as a result of this work. The wide rurrent discussions on the theory of network ~t r u c t u r e s~-~ indicate that a rigorous analysis of this very complex problem must await further experimental data on numerous other polymer systems.

Gel permeation chromatography can contribute significantly to the guidance of polymer synthesis activities. Qualitative information about the effect of reaction variables on molecular weight distribution is satisfactory for such studies. Reaction mixtures can be analyzed without isolating the products of interest. Data are available soon after the reaction is completed, enabling future work to benefit from the information generated. The polymerization of propylene oxide in the presence of 1,5‐pentanediol and hydrocarbon solvent was shown to proceed in two steps. All the diol first reacted with propylene oxide to form an adduct at each hydroxyl function. Propagation with propylene oxide then proceeded with no further initiation and no termination reactions. Attempts to synthesize block copolymers in hydrocarbon solvent at 50°C. by the addition of a second monomer to polystyryl anions gave binodal molecular weight distributions. Polystyryl anions were shown to form species inactive toward further polymerization. Gel permeation chromatography also demonstrated the presence of a chemical composition heterogeneity in these products.

No abstract