Lithium tensile properties

The plasticizing effects of a larger number of metal stearates on the zinc sulfonate ionomer were examined, and the results are given in Table III in terms of flow and mechanical properties. Lead stearate, zinc stearate, and ammonium stearate significantly improved melt flow along with the stearic acid control. The barium, magnesium, sodium, lithium, and calcium stearates showed little, if any, improvement in melt flow. Of the four melt flow improvers, both stearic acid and ammonium stearate exerted deleterious effects on tensile properties. Only the zinc and lead stearates substantially improved tensile properties. Thus, while zinc stearate is not unique, the number of fatty acid derivatives that improve both melt flow and mechanical properties is limited. 

The swelling of cotton with an aqueous solution of sodium hydroxide is an important com mercial treatment. It is called mercerization after its discoverer, John Mercer, who took a patent on the process in 1850 [308]. Other alkali metal hydroxides, notably lithium hydroxide and potassium hydroxide, will also mercerize cotton, but normally sodium hydroxide is used. Mercerization is utilized to improve such properties as dye affinity, chemical reactivity, dimensional stability, tensile strength, luster, and smoothness of the cotton fabrics [309]. The treatment is normally applied either to yarn or to the fabric itself either in the slack state to obtain, for example, stretch products, or under tension to improve such properties as strength and luster. The interaction of alkali metal hydroxides and cellulose has been extensively reviewed. Earlier reviews can be traced from relatively recent ones [99,310,311]. 

Physical test properties on some cured rubber stocks prepared from lithium-catalyzed butadiene polymers are listed in Tables V and VI with appropriate controls. The results are only roughly indicative of the potential properties of rubbers made from lithium-catalyzed butadiene polymers because of the limited quantity of polymer available. The tensile data in Table VI indicate that compounded stocks from the lithium polymers are about equal or slightly inferior to the emulsion and sodium polymer controls in regard to these properties however, a hot tensile (lOO C.) on a cured compound from lithium polybutadiene was 325 pounds per square inch compared to 200 to 250 for an emulsion polybutadiene control. The internal friction of cured stocks from the lithium-catalyzed butadiene polymers is similar in magnitude to the emulsion or sodium polymer controls at 50 C. but higher at 100 °C. All lithium polymers, even those with low Mooney viscosities, gave cured compounds with high values of dynamic modulus. 

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