Dual‐functional, aromatic, epoxy‐methacrylate monomers from bio‐based feedstocks and their respective epoxy‐functional thermoplastics

Abstract

Dual‐functional monomers consist of two distinctly different functional groups that enable chemical versatility. The most readily available epoxy‐methacrylate dual‐functional monomer is glycidyl methacrylate (GMA). In an effort to produce bio‐based, aromatic complements to GMA, asymmetric phenolic diols (vanillyl alcohol, syringyl alcohol, gastrodigenin, and tyrosol) were identified and selectively epoxidized at the aromatic hydroxyl followed by subsequent esterification at the aliphatic hydroxyl to prepare dual functional monomers, vanillyl alcohol epoxy‐methacrylate (VAEM), syringyl alcohol epoxy‐methacrylate (SAEM), gastrodigenin epoxy‐methacrylate (GDEM), and tyrosol epoxy‐methacrylate (TEM). These monomers are viable platforms for a multitude of applications due to their unique chemical functionalities. VAEM, SAEM, GDEM, and TEM were homopolymerized individually to produce aromatic, bio‐based epoxy‐functional thermoplastics analogous to poly(GMA). The molecular weight distributions and thermal properties of each polymer were evaluated, as were the surface characteristics of flow‐coated thin films from these polymers. Most of the newly prepared epoxy‐functional thermoplastics exhibited increased thermal stability (initial decomposition temperatures >260 °C in air) relative to poly(GMA), while retaining similar glass transition temperatures (~ 65 °C) and surface energies (~ 53 mJ m−2); thus, these materials could be substituted for poly(GMA) and enable use in higher‐temperature applications. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 673–682

Epoxy‐functional thermoplastic copolymers and their incorporation into a thermosetting resin

“…As poly(GMA) homopolymer has a higher T g (66 C) than poly(VAEM) homopolymer (60 C), this is to be expected. 21 The synthesized thermoplastic copolymers contain several reactive epoxy groups on each polymer chain, an estimated 7-11 epoxies per chain based on 1 H-NMR spectroscopy. The chains are anticipated to have approximately evenly spaced epoxy groups due to the controlled nature of RAFT reactions.…”

“…10,[19][20] VAEM is a derivative of the lignin-based aromatic diol vanillyl alcohol, created through the intentional synthesis of monoglycidyl ether of vanillyl alcohol followed by an esterification of the aliphatic hydroxyl with methacryloyl chloride. 21 Polymerized VAEM, poly(VAEM), has been shown to have higher thermal stability than poly(GMA), which could be beneficial in epoxy IPNs. 21 IPN studies have been completed with reactive thermoplastics containing poly(GMA); however, those typically employ a block copolymer configuration in semi-IPNs or reactive end groups in grafted IPNs and leave room for further study.…”

“…21 Polymerized VAEM, poly(VAEM), has been shown to have higher thermal stability than poly(GMA), which could be beneficial in epoxy IPNs. 21 IPN studies have been completed with reactive thermoplastics containing poly(GMA); however, those typically employ a block copolymer configuration in semi-IPNs or reactive end groups in grafted IPNs and leave room for further study. [22][23][24] With the intent to use epoxy-functional thermoplastics as resin modifiers, copolymers were created with varying amounts of MMA, a widely available and common methacrylate monomer with desirable physical attributes and properties, including a T g of approximately 110 C and its methacrylate structure.…”

“…All chemicals used to synthesize VAEM are mentioned above. 21 All chemicals mentioned above were used without further purification.…”

TG/DSC/FTIR/QMS analysis of environmentally friendly poly(citronellyl methacrylate)-co-poly(benzyl methacrylate) copolymers

“…So far, it is known to use isosorbide to obtain acetylated acrylic and methacrylic isosorbide monomers by the tandem esterification with acetic anhydride and methacrylic anhydride [19][20][21][22] or syringyl methacrylate, creosyl methacrylate [23][24][25], vanillin methacrylate [24][25][26] to prepare bio-based polymeric materials for high-temperature applications. The use of new alkyl lactate monomers (methyl, ethyl, npropyl and n-butyl lactate acrylates) to the preparation of bio-based acrylates is also known [27][28][29][30][31].…”