Palladium supported on alumina was used to hydrogenate soybean and canola oil. Previous literature reports indicated that palladium forms moretrans isomers than nickel. At 750 psig, 50 ppm palladium, and at 70 C, only 9.4%trans were formed when canola oil was hydrogenated to IV 74. In general, high pressure and low temperature favored lowtrans formation with no appreciable loss in catalyst activity. The effect of pressure, temperature and catalyst concentration on reaction rate,trans formation and selectivity is presented. A survey of various catalyst supports is discussed. Apparent activation energies of 6.3 to 8.9 kcal/mol were obtained; they are in good agreement with values reported in the literature.

The hydrogenation of canola oil was studied using palladium black as a potential catalyst for producing partially hydrogenated fats with lowtrans‐isomer content. Pressure (150‐750 psig) appeared to have the largest effect ontrans‐isomer formation. At 750 psig, 90 C and 560 ppm metal concentration, a maximum of 18.7%trans isomers was obtained at IV 53. A nickel catalyst produces about 50%rans isomers at the same IV. For palladium black, the linolenate and linoleate selectivities were 1.2 and 2.7, respectively. The maximum level oftrans isomers observed ranged from 18.7% to 42.8% (150 psig). Temperature (30‐90 C) and catalyst concentration (80‐560 ppm) affected the reaction rate with little effect ontrans‐isomer formation and selectivities. At 250 psig and 50 C, supported palladium (5% Pd/C) appeared to be twice as active as palladium black. At 560 ppm Pd, 5% Pd/C produced 30.2%trans (IV 67.5), versus 19.0%trans for palladium black (IV 68.9). Respective linoleate selectivities were 15 and 6.6, while linolenate selectivities were approximately unity. Analysis of the oil samples by neutron activation showedapproximately a 1 ppm, Pdresidue after filtration.

The geometrical isomerization characteristics of 5% Pd/alumina were investigated using response surface methodology. From the response surface, it was observed as expected that moretrans isomers were formed at lower pressures and higher temperatures. A doubling of the metal concentration from 50 to 100 ppm resulted in a small increase in isomerization in soybean oil, while for canola oil the same increase had a larger effect, especially at lower pressures. Similarly, an increase in temperature increases geometrical isomerization, especially at lower pressures, but the effect is more pronounced for canola than for soybean oil. Positional isomers were determined by oxidative ozonolysis in BF3‐MeOH and subsequent GLC analysis. Higher pressures suppressed positional isomerization. The effect of various catalyst supports on positional isomerization was also investigated.

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The development and optimization of reliable polymerization methods are needed for the synthesis of degradable imine-based conjugated polymers, which are attractive materials for transient electronics. Direct arylation polymerization (DArP) has emerged as a sustainable and atom-economical synthetic method for the preparation of well-defined conjugated polymers. Compared to polymerization methods such as imine polycondensation or Stille cross-coupling polymerization which require monomer functionalization, direct arylation proceeds via C-H activation and thereby reduces synthetic complexities and toxic by-products. Here we report the first use of DArP for the synthesis of an imine-based indacenodithiophene (IDT) copolymer, p(IDT-TIT). Polymers prepared via DArP can result in branched or cross-linked polymer chains due to the reactivity of C-H bonds in the monomers. In this report, we demonstrate a systematic study focusing on the reaction conditions needed to prepare p(IDT-TIT) via DArP with tetramethylethylenediamine as a co-ligand. The degradable polymer is characterized via nuclear magnetic resonance spectroscopy, high-temperature gel permeation chromatography, and ultraviolet- visible-near-infrared spectroscopy. With the simplicity of monomer preparation and reaction conditions, we anticipate this efficient synthetic protocol will lead to higher synthetic adoption in the research community to aid the exploration of high-performance imine-based degradable materials.