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A series of three butadiene/methacrylic acid copolymers and three butadiene/2-methyl-5-vinyl pyridine copolymers were evaluated for Young's modulus and stress relaxation modulus between -75C and +75C. Corresponding members of the acidic and basic copolymer series were stoichiometrically combined to provide an intermolecularly hydrogen bonded material which was tested in the same manner. Comparison between the observed modulustemperature curves for the mixed material and the average of the parent materials' modulus-temperature curve reveals a regular, temperature dependent increase in Young's modulus above Tg. Below Tg the rate of increase decreases. The stress relaxation curves of the acidic, basic and mixed copolymers were normalized with respect to Tg. The curves were then differentiated to provide relaxation spectrum curves. The comparison of the average relaxation spectrum curves for the parent materials with that obtained for the mixed material shows depression of short time relaxation mechanisms. Infrared investigations of the hydrogen bond absorptions in stretched films are also discussed. (Author), See also AD-437 336.

In an effort to determine the effects of ionic interactions on the physical properties of polymers, two series of butadiene copolymers were tested for stress strain and stress relaxation behavior. The first group of copolymers were those of butadiene and methacrylic acid which were converted to their anionic form by titration with LiOCH3. The second series were copolymers with 2-methyl, 5-vinyl pyridine which were reacted with CH3I to form the polycations. Finally stoichiometric mixed polysalts were prepared by mixing solutions of the oppositely charged polyions. The modulus-temperature currves of the various materials showed relatively stable plateau values over moderate temperature spans. Both the pyridinium copolymers and the mixed polysalts showed sharp decreases in modulus over a narrow temperature range. This unusual behavior was confirmed in the stress relaxation tests, being manifested as a rapid increase in the shift factors and E(visc), the activation energy for viscous flow. The patterns indicate a transition of one form or another but whether it is indicative of the onset of ionic interchange is not clear. (Author), See also Part 2, dated Mar 66, AD-630 019.

Two series of styrene copolymers were prepared, containing, respectively, acidic and basic comonomers. The mechanical properties of these copolymers were determined for several temperatures below T sub g. Stoichiometric mixtures of these acidic and basic copolymers were studied over the same temperature range, and their mechanical properties compared to those of the parent materials. It was found that the stoichiometric mixtures showed increased modulus, tensile strength and relaxation times. The increases can be related to functional group content and temperature through simple equations. (Author)