Browsing by Subject "internal catalysis"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Supporting data for Dynamic Aliphatic Polyester Elastomers Crosslinked with Aliphatic Dianhydrides
    (2023-01-27) Meyersohn, Marianne S; Haque, Farihah M; Hillmyer, Marc A; hillmyer@umn.edu; Hillmyer, Marc, A; University of Minnesota, Department of Chemistry
    These files contain primary data along with associated output from instrumentation supporting all results reported in Meyersohn, M. et. al. "Dynamic Aliphatic Polyester Elastomers Crosslinked with Aliphatic Dianhydrides." In Meyersohn, M. et. al. we found: Chemically crosslinked elastomers are a class of polymeric materials with properties that render them useful as adhesives, sealants, and in other engineering applications. Poly(γ-methyl-ε-caprolactone) (PγMCL) is a hydrolytically degradable and compostable aliphatic polyester that can be biosourced and exhibits competitive mechanical properties to traditional elastomers when chemically crosslinked. A typical limitation of chemically crosslinked elastomers is that they cannot be reprocessed; however, incorporation of dynamic covalent bonds (DCBs) can allow for bonds to reversibly break and reform under an external stimulus, usually heat. In this work we the study dynamic behavior and mechanical properties of PγMCL elastomers synthesized from aliphatic dianhydride crosslinkers. The crosslinked elastomers in this work were synthesized using the commercially available crosslinkers, 1,2,4,5-cyclohexanetetracarboxylic dianhydride (CHDA), and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and three-arm hydroxy-telechelic PγMCL star polymers. Stress relaxation experiments on the crosslinked networks showed an Arrhenius dependence of viscosity with temperature with an activation energy of 118 ± 8 kJ/mol, which agrees well with the activation energy of the exchange chemistry obtained from small molecule model studies. Dynamic mechanical thermal analysis and rheological experiments confirmed the dynamic nature of the networks and provided insight into the mechanism of exchange (i.e., associative, or dissociative). Tensile testing showed that these materials can exhibit high strains at break and low Young’s moduli, characteristic of soft, strong elastomers. By controlling the exchange chemistry and understanding the effect of macromolecular structure on mechanical properties, we prepared high performing elastomers that can be rapidly reprocessed at moderately elevated temperatures.