TY - JOUR
T1 - Multifunctional Biobased Benzoxazines Blended with an Epoxy Resin for Tunable High-Performance Properties
AU - Chong, Alexandra M.
AU - Salazar, Sarah A.
AU - Stanzione, Joseph F.
N1 - Funding Information:
We would like to acknowledge financial support of the U.S. Army Research Laboratory through Cooperative Agreements W911NF-14-2-0086 and W911NF-16-2-0225. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the U.S. Army Research Laboratory or the U.S. government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein. We would like to thank Kelli Hambleton (Rowan University) and Joseph Mauck (Cardolite Corporation) for assisting with the synthesis of bisguaiacol. We would also like to thank Amanda McCahill and Kelly Yorke (Rowan University) for their assistance with preliminary experiments associated with this work and Jonathan Foglein of the Department of Chemistry & Biochemistry at Rowan University for his assistance with the NMR facility.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/5/3
Y1 - 2021/5/3
N2 - Biobased polybenzoxazines incorporate natural phenolic structures to produce polymers with near-zero shrinkage, high char yields, and high chemical and thermal resistances, garnering great interest as sustainable high-performance polymers. Herein, difunctional and trifunctional benzoxazine monomers, bisguaiacol-furfurylamine (BG-f) and triguaiacol-furfurylamine (TG-f), respectively, were synthesized from renewable guaiacol, vanillin, and furfurylamine using solventless procedures. Benzoxazines were blended with varying weights of epoxy resin and thermally cured to produce benzoxazine-epoxy (BG-f-E and TG-f-E) polymers. These polymers displayed glass transition temperatures ranging from 130 to 157 °C (peak of the loss modulus), thermal stabilities from 299 to 329 °C in both N2 and air, and char yields ranging from 35% to 58%. BG-f-E and TG-f-E with greater benzoxazine content produced stiffer materials exhibiting glassy storage moduli values upward of 3.48 and 3.69 GPa, respectively. BG-f-E polymers displayed higher molecular weight between cross-link values (646 g mol-1 to 981 g mol-1) compared to TG-f-E polymers (316 g mol-1 to 465 g mol-1) and exhibited fracture energies upward of 404 J m-2. These investigations demonstrate the utility of incorporating biobased benzoxazines into benzoxazine-epoxy resin formulations to design sustainable polybenzoxazines with tunable thermal and mechanical properties for high-performance polymer applications.
AB - Biobased polybenzoxazines incorporate natural phenolic structures to produce polymers with near-zero shrinkage, high char yields, and high chemical and thermal resistances, garnering great interest as sustainable high-performance polymers. Herein, difunctional and trifunctional benzoxazine monomers, bisguaiacol-furfurylamine (BG-f) and triguaiacol-furfurylamine (TG-f), respectively, were synthesized from renewable guaiacol, vanillin, and furfurylamine using solventless procedures. Benzoxazines were blended with varying weights of epoxy resin and thermally cured to produce benzoxazine-epoxy (BG-f-E and TG-f-E) polymers. These polymers displayed glass transition temperatures ranging from 130 to 157 °C (peak of the loss modulus), thermal stabilities from 299 to 329 °C in both N2 and air, and char yields ranging from 35% to 58%. BG-f-E and TG-f-E with greater benzoxazine content produced stiffer materials exhibiting glassy storage moduli values upward of 3.48 and 3.69 GPa, respectively. BG-f-E polymers displayed higher molecular weight between cross-link values (646 g mol-1 to 981 g mol-1) compared to TG-f-E polymers (316 g mol-1 to 465 g mol-1) and exhibited fracture energies upward of 404 J m-2. These investigations demonstrate the utility of incorporating biobased benzoxazines into benzoxazine-epoxy resin formulations to design sustainable polybenzoxazines with tunable thermal and mechanical properties for high-performance polymer applications.
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U2 - 10.1021/acssuschemeng.1c01338
DO - 10.1021/acssuschemeng.1c01338
M3 - Article
AN - SCOPUS:85105040719
VL - 9
SP - 5768
EP - 5775
JO - ACS Sustainable Chemistry and Engineering
JF - ACS Sustainable Chemistry and Engineering
SN - 2168-0485
IS - 17
ER -