AND SUMMARYThe radical expansion behavior of saturated, mono-acid triglycerides has been studied, using X-ray diffractometry. The isothermal transition of metastable/3'-polymorph into the stable/3-form is diffusion controlled and appears to follow two distinct rate relationships. The rate of the ff~/~ transition is also effected by the nature of the precursor polymorph. In common with long chain polymers, quenched, annealed samples of melted tristearin (SSS) reach the stable ~polymorphic state faster than isothermally crystallized samples of melt annealed at the same temperature. Somewhat speculative mechanisms for these processes are discussed in this paper.

SynopsisBecause it represents a polymer system routinely used in a highly corrosive environment, the resin-bonded cellulose separator is a paradigm of bad polymer application that succeeds. It succeeds because of the remarkable properties of cellulose itself, and through the formation of a highly modified structure that serves to protect both the resin and the cellulose in a reactive environment known to completely degrade both. X-ray diffraction analysis was used to determine the quality of retained cellulose in lead-acid battery separators made by impregnating thick cellulose matrixes with phenolic resins. The hydrolytic weight loss of separators stored in battery acid at 52°C was also measured and related to x-ray diffraction measurements of intensive degree of crystallinity and "qualitative perfection." The x-ray diffraction analyses and hydrolysis measurements are consistent with the formation of a copolymer between the cellulose and the impregnating resin. Treated and rewetted a-cellulose displays a capability for reorganization, indicated by increases in intensive crystallinity and qualitative perfection that are absent in the resin-bonded cellulose separator matrix. Rewetting of the separator matrix actually decreased the "qualitative perfection" of the cellulose present. X-ray diffraction measurements indicate that extensive crystallinity of acid-treated separators increases, due probably to the higher reactivity of the "so-called" amorphous fraction of the cellulose present. The degree of crystallinity, an intensive measure, does not change significantly during acid treatment, but the "qualitative perfection" of the cellulose decreases with time of hydrolysis and increases in acid strength.

AND SUMMARYAmong supported nickel-based hydrogenation catalysts, the Ni crystallite size apparently plays a secondary role in net hydrogenation activity for undistilled tallow fatty acids and nonselective hydrogenation of oxidized soybean oil. The nickel crystallite size measured by the x-ray diffraction profile broadening technique of Scherrer varied between 55 A and 150 A. The commercial catalyst with the smallest nickel crystatlite size, in the samples studied, was not the most active for hardening soybean oil, while fatty acid hydrogenation showed a large crystallite catalyst to have the highest activity. Since the percent reduced nickel used in catalytic hydrogenation is not well known if the Ni/NiO ratio is poorly defined, relative activities were then correlated with qualitative x-ray diffraction measurements of the Ni/NiO values. Again, there was no trend in activity as a function of Ni/NiO. This apparent puzzle is probably due to real differences in the micro structure of the catalyst support. A series of experimental reductions using a common green catalyst led to very good correlations between net activity for fatty acid hydrogenation and the crystallite size and Ni/NiO ratio. On a given support, the crystallite dimension can be modified by the reduction treatment and is not sharply fixed by the selection of nickel salt and support. If the stoichiometric ratio of hydrogen is lowered, the crystallite dimension is reduced, but so is the qualitative efficiency of reduction (Ni/NiO), with the result that an exceptionally small crystallite size catalyst may be less active than one with larger crystals, but with more reduced Ni/unit weight.

cell was the best, and that of the platinum was the worst.2. The main components of the exhaust gas were nitrogen and hydrogen. A little ammonia was detected when the operating temperature was 60~ 3. The hydrogen content of the exhaust gas decreases and fuel efficiency increases in accordance with increases in the current density. At a high current density, it is presumed that hydrogen which is produced by side reaction is caught by the anode and is used for further reaction.4. The hydrogen content of the exhaust gas increases and fuel efficiency decreases with increasing hydrazine concentration. It seems that the decomposition of hydrazine which is not used effectively for electrochemical reaction increases with increasing hydrazine concentrations.5. The hydrogen in exhaust gas increases and fuel efficiency decreases with increasing cell temperatures. ABSTRACTResin-bonded paper separators suffer some loss of crystalline material on extended storage in battery grade H2SO4. Similar separators from cycled batteries suffer order of magnitude losses of crystallinity. Scanning electron microscopy has found Pb-salts of two kinds; those grown in regions of high and low supersaturation. The latter often obtain crystal dimensions larger than 30~. Comparison with other separator materials used in Pb/acid batteries has led to a model of separator failure based on mechanical abrasion, fluid motion, and crystallization in large pores. The separator matrix is weakened by brittle fracture of the fiber network, accompanied by minor hydrolytic loss of material. These lead in turn to pore enlargement that can enhance the growth of large, well-ordered crystals. A somewhat speculative mechanism for perforation failure of large-pored separators is given. * Electrochemical Society Active Member.

Examines the chemistry of rocket fuels and engines.