The homopolymer and many of the copolymers of N‐acrylylglycinamide yield thermally reversible gels in water. These systems are uniquely suitable for studying synthetic photographic gelatin substitutes and for understanding the mechanism of the gelation process. Polymerization of N‐acrylylglycinamide has been studied under a variety of conditions. The homopolymer is aggregated in dilute aqueous solution and probably molecularly dispersed in 2M thiocyanate solution. At concentrations of several per cent, in water, thermally reversible gels are formed whose melting points rise with increasing concentration and increasing molecular weight. The heat of gelation crosslinking has been calculated to be −8.8 kcal./mole of crosslinks. Introduction of small amounts of carboxyl groups into the polymer raises the melting points of the aqueous gels. The effect of various organic and inorganic reagents on gelation is presented. The ability to prepare copolymers which can be flocculated has been demonstrated as well as the usefulness of the monomer in certain types of photoresist systems. Copolymerization with acrylic acid and β‐aminoethyl vinyl ether has been studied, and the r1 and r2 values for these systems have been calculated as well as Q and e values for N‐acrylylglycinamide.

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synopais Polyethylenimine (PEI) has been oxidized with aqueous hydrogen peroxide to yield a hygroscopic, water-soluble, slightly basic, yellow polymeric solid (OPEI) containing about 25% oxygen. Some chain degradation accompanies oxidation. The nature of the product varies somewhat with preparative conditions. OPEI, in the presence of strong alkali, reduces silver salts and peptizes a portion of the silver. By use of infrared, ultraviolet, and proton magnetic resonance spectroscopy together with qualitative testing, OPEI has been found to contain carboxyl groups, unoxidized primary amine groups, tertiary amine oxide, small amounts of aldehyde and nitrone groups, and a considerable amount of secondary nmide. The probable reaction sequence is: PEI + dialkylhydroxylamine + nitrone + oxazirane + rearranged product. Oxazirane groups appear to be absent, as well as oxime, nitro, nitrite, and nitrate. The groups which reduce silver salts are not known with certainty but are probably of the hydroxylamine.type. The carboxyl content of OPEI is associated with the lower molecular weight species which are present.

Vinyl trifluoroacetate and its homopolymer have been investigated. In copolymerization, the monomer behaves normally, having a Q similar to that of vinyl acetate and a positive e value resulting from fluorine substitution. Unlike the vinyl acetate system, polyvinyl trifluoroacetate is insoluble in its monomer and polymerization leads to no increase in DP with conversion. It is suspected that substitution of CH3 by CF3 has greatly reduced chain transfer and branching. Infrared spectra of vinyl trifluoroacetate and its polymer are presented and solubilities of the latter reported. Polyvinyl trifluoroacetate is very unstable to the hydrolytic loss of the perfluoro acid. The fluoropolymer is much harder than polyvinyl acetate and higher values are obtained for its softening point and apparent second‐order transition temperature. Although no difference can be found by infrared measurements between authentic polyvinyl alcohol and that obtained by hydrolysis of the fluoropolymer, a large difference in their water solubilities exists. Polyvinyl trifluoroacetate is readily oriented by stretching and some polarized infrared absorption data are presented. X‐ray diffraction photographs of stretched specimens indicate moderate order and considerable orientation. These results are surprising when considered in the light of the general concepts regarding polymer structure and crystallinity. Extremely highly ordered and highly birefringent polyvinyl alcohol can be obtained readily from stretched polyvinyl trifluoroacetate by conversion of the latter with gaseous ammonia.

Cation initiated polymerizations of various monomers were carried out in the presence of several polystyrene derivatives in an effort to obtain graft copolymers. No success was achieved in grafting with vinyl butyl ether, vinyl ethyl ether, isobutylene, N‐vinylpyrrolidone, or pinene under the particular experimental conditions employed. In the experiments involving vinyl n‐butyl ether, the presence of the various polystyrenes appeared to have no effect on the polymerization of this monomer or on the DP of the polyvinylbutyl ethers obtained. However, when styrene was polymerized in the presence of poly‐p‐methoxystyrene (PPMS), graft copolymer was readily obtained. The success of this reaction demonstrates the feasibility of preparing graft copolymers by an ionic mechanism and yields additional proof of an ionic chain transfer reaction with aromatic species in which the latter are incorporated into the chain. Data obtained on the styrene‐PPMS system are discussed in terms of a simple kinetic scheme. The molecular termination constant of PPMS was found to be only 1/67th of that of p‐methylanisole, a low molecular weight analogue. The low chain transfer effectiveness of PPMS is believed to be due to constraints placed on the availability of the transfer sites which are linked in a polymeric chain.