Vitrification: Versatile Method To Modulate Properties of Myrcene-Based Rubbers

作者：Farhad Asempour, Milan Marić · 发表于：ACS Applied Polymer Materials · 年份：2023 · DOI：10.1021/acsapm.3c00914 · 被引用次数：19 · 研究领域：Polymer composites and self-healing、Synthetic Organic Chemistry Methods、Polymer Nanocomposites and Properties

We report bio-derived vitrimeric rubbers with weldability and excellent reprocessability. Reversible-deactivation radical copolymerization of the commercially available terpene-based β-myrcene with 10 to 30 mol % (2-acetoacetoxy)ethyl methacrylate (AAEMA) afforded linear prepolymers, which were cross-linked in a single step treatment with difunctional amine, the vegetable oil-derived Priamine 1075, or trifunctional amine tris(2-aminoethyl)amine (TREN). Decoupling the networks’ backbone structure and cross-linkers led to high tunability of the vitrimers’ final mechanical and rheological properties using prepolymer composition, molecular weight, nature and concentration of cross-linker, and cross-linking density. Glass transition temperature ( T g ) of the vitrimers ranged between −49 and −5 °C, while the average elongation and stress at break ranged from ∼83% and 0.18 MPa to ∼30% and 1.68 MPa, respectively from the lowest, 0.12 mol/L, to the highest, 0.98 mol/L, cross-linking densities. The characteristic features of dynamic vinylogous urethane-vitrimers were confirmed over at least three reprocessing cycles by grounding and hot-pressing at 110 °C. No appreciable changes in the ATR-FTIR spectra, T g, decomposition temperatures, tensile properties, and storage modulus were observed due to reprocessing. Furthermore, the incorporation of 5 mol % epoxy-based glycidyl methacrylate into the prepolymer led to the formation of a network with dual static and dynamic cross-links. Compar...