TY - JOUR
T1 - Synthesis and Characterization of a Low-Molecular-Weight Novolac Epoxy Derived from Lignin-Inspired Phenolics
AU - Hambleton, Kelli M.
AU - Stanzione, Joseph F.
N1 - Publisher Copyright:
© 2021 The Authors. Published by American Chemical Society.
PY - 2021/9/21
Y1 - 2021/9/21
N2 - The need for renewable polymers capable of replacing their petrochemical counterparts continues to grow as sustainability concerns rise. Bisguaiacol (BG), a bioinspired alternative to bisphenol-A (BPA), has been synthesized using vanillyl alcohol and guaiacol via an electrophilic aromatic condensation. Purification provides both BG and an oligomeric coproduct with a consistent number average molecular weight and dispersity of ∼650 Da and ∼1.00, respectively. This coproduct has been well characterized as a low-molecular-weight novolac averaging five hydroxyls per molecule and was transformed into an epoxy resin suitable for use in thermosetting resins. The bioinspired thermoset produced in this work, consisting of the epoxidized coproduct and an amine curing agent (Epikure W), exhibited a glass transition temperature over 100 °C and glassy storage modulus value of ∼3 GPa at 25 °C. When compared to a commercial cresol novolac epoxy, the cured epoxidized coproduct resin shows comparable thermal and thermomechanical properties. When compared to a commercial BPA-based resin, the cured epoxidized coproduct resin shows improved mode 1 fracture values of 1.34 J m1/2 (K1C) and 448.16 J/m2 (G1C). By utilizing the coproduct strategically, the overall production of BG has the potential to become more economically feasible.
AB - The need for renewable polymers capable of replacing their petrochemical counterparts continues to grow as sustainability concerns rise. Bisguaiacol (BG), a bioinspired alternative to bisphenol-A (BPA), has been synthesized using vanillyl alcohol and guaiacol via an electrophilic aromatic condensation. Purification provides both BG and an oligomeric coproduct with a consistent number average molecular weight and dispersity of ∼650 Da and ∼1.00, respectively. This coproduct has been well characterized as a low-molecular-weight novolac averaging five hydroxyls per molecule and was transformed into an epoxy resin suitable for use in thermosetting resins. The bioinspired thermoset produced in this work, consisting of the epoxidized coproduct and an amine curing agent (Epikure W), exhibited a glass transition temperature over 100 °C and glassy storage modulus value of ∼3 GPa at 25 °C. When compared to a commercial cresol novolac epoxy, the cured epoxidized coproduct resin shows comparable thermal and thermomechanical properties. When compared to a commercial BPA-based resin, the cured epoxidized coproduct resin shows improved mode 1 fracture values of 1.34 J m1/2 (K1C) and 448.16 J/m2 (G1C). By utilizing the coproduct strategically, the overall production of BG has the potential to become more economically feasible.
UR - https://www.scopus.com/pages/publications/85115242109
UR - https://www.scopus.com/inward/citedby.url?scp=85115242109&partnerID=8YFLogxK
U2 - 10.1021/acsomega.1c02799
DO - 10.1021/acsomega.1c02799
M3 - Article
AN - SCOPUS:85115242109
SN - 2470-1343
VL - 6
SP - 23855
EP - 23861
JO - ACS Omega
JF - ACS Omega
IS - 37
ER -