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Browsing by Author "Ellison, Christopher"

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    Data for Accelerated hydrolysis of amorphous polylactide containing salicylate additives
    (2024-11-25) Rachita, Eric; Larison, Taylor; Hillmyer, Marc; Ellison, Christopher; cellison@umn.edu; Ellison, Christopher; Ellison Research Group; Hillmyer Research Group
    Blends of amorphous-grade polylactide (PLA) with low levels of salicylic acid (SA), disalicylide (DS), or oligosalicylate (OS) were prepared using scalable melt processing techniques. The glass transition temperature (Tg), tensile properties, and shelf-life stability of the salicylate-containing blends were nearly identical to neat PLA (Tg = 56.3 °C). The inclusion of salicylate additives accelerated sample mass loss in artificial seawater at 50 °C by up to a factor of three as compared to neat PLA. Water uptake occurred after the PLA molar mass dropped below 15 kg/mol, corresponding to the point that the Tg of the remaining material dropped below 50 °C. The onset of mass loss was observed after PLA hydrolyzed into 2 kg/mol fragments, coinciding with leaching of SA and DS; OS remained in the blends for longer immersion periods. The rate of molar-mass loss in 1 wt.% salicylate-containing blends was up to twice as fast as the rate of neat PLA. Degradation-induced PLA crystallization occurred once Tg dropped below 50 °C and mass loss slowed after the degree of crystallinity (Xc) exceeded 50%. We conclude that a low concentration of carboxylic acid groups from salicylate-containing compounds is sufficient to enhance PLA degradability without sacrificing material performance.
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    Data for Equilibrium Phase Behavior of Gyroid-Forming Diblock Polymer Thin Films
    (2024-08-08) Magruder, Benjamin; Ellison, Christopher; Dorfman, Kevin; dorfman@umn.edu; Dorfman, Kevin; Dorfman Research Group
    The dataset contains the results of thin-film self-consistent field theory calculations for the double-gyroid phase and other related phases in AB diblock polymers. All results used to construct the figures in the referenced manuscript are included in this dataset, along with many of the scripts used to perform the analysis in the manuscript. To reduce the size of the dataset, we opted to include only the first and last field file in each parameter sweep, though we kept the corresponding summary file at every state point in every sweep, and included all necessary input files to regenerate the data if desired. The PSCF software package (C++ version) was used to generate this dataset (https://github.com/dmorse/pscfpp).