Adenine as Epoxy Resin Hardener for Sustainable Composites Production with Recycled Carbon Fibers and Cellulosic Fibers

In this work, Adenine is proposed, for the first time, as a cross-linker for epoxy resins. Adenine is an amino-substituted purine with heterocyclic aromatic structure showing both proton donors, and hydrogen bonding ability. DSC studies show that adenine is able to positively cross-link a biobased D...

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Main Authors: Stefano Merighi, Laura Mazzocchetti, Tiziana Benelli, Loris Giorgini
Format: Article
Language:English
Published: MDPI AG 2020-12-01
Series:Polymers
Subjects:
Online Access:https://www.mdpi.com/2073-4360/12/12/3054
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author Stefano Merighi
Laura Mazzocchetti
Tiziana Benelli
Loris Giorgini
author_facet Stefano Merighi
Laura Mazzocchetti
Tiziana Benelli
Loris Giorgini
author_sort Stefano Merighi
collection DOAJ
description In this work, Adenine is proposed, for the first time, as a cross-linker for epoxy resins. Adenine is an amino-substituted purine with heterocyclic aromatic structure showing both proton donors, and hydrogen bonding ability. DSC studies show that adenine is able to positively cross-link a biobased DGEBA-like commercial epoxy precursor with good thermal performance and a reaction mechanism based on a <sup>1</sup>H NMR investigation has been proposed. The use of such a formulation to produce composite with recycled short carbon fibers (and virgin ones for the sake of comparison), as well as jute and linen natural fibers as sustainable reinforcements, leads to materials with high compaction and fiber content. The curing cycle was optimized for both carbon fiber and natural fiber reinforced materials, with the aim to achieve the better final properties. All composites produced display good thermal and mechanical properties with glass transition in the range of HT resins (<i>T</i><sub>g</sub> > 150 °C, E’ =26 GPa) for the carbon fiber-based composites. The natural fiber-based composites display slightly lower performance that is nonetheless good compared with standard composite performance (<i>T</i><sub>g</sub> about 115–120 °C, E’ = 7–9 GPa). The present results thus pave the way to the application of adenine as hardener system for composites production.
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spelling doaj.art-5b064fabaa5f40a6aaf189ae9d1e44052023-11-21T01:47:17ZengMDPI AGPolymers2073-43602020-12-011212305410.3390/polym12123054Adenine as Epoxy Resin Hardener for Sustainable Composites Production with Recycled Carbon Fibers and Cellulosic FibersStefano Merighi0Laura Mazzocchetti1Tiziana Benelli2Loris Giorgini3Department of Industrial Chemistry “Toso Montanari” and INSTM UdR-Bologna, University of Bologna, Viale Risorgimento 4, 40136 Bologna, ItalyDepartment of Industrial Chemistry “Toso Montanari” and INSTM UdR-Bologna, University of Bologna, Viale Risorgimento 4, 40136 Bologna, ItalyDepartment of Industrial Chemistry “Toso Montanari” and INSTM UdR-Bologna, University of Bologna, Viale Risorgimento 4, 40136 Bologna, ItalyDepartment of Industrial Chemistry “Toso Montanari” and INSTM UdR-Bologna, University of Bologna, Viale Risorgimento 4, 40136 Bologna, ItalyIn this work, Adenine is proposed, for the first time, as a cross-linker for epoxy resins. Adenine is an amino-substituted purine with heterocyclic aromatic structure showing both proton donors, and hydrogen bonding ability. DSC studies show that adenine is able to positively cross-link a biobased DGEBA-like commercial epoxy precursor with good thermal performance and a reaction mechanism based on a <sup>1</sup>H NMR investigation has been proposed. The use of such a formulation to produce composite with recycled short carbon fibers (and virgin ones for the sake of comparison), as well as jute and linen natural fibers as sustainable reinforcements, leads to materials with high compaction and fiber content. The curing cycle was optimized for both carbon fiber and natural fiber reinforced materials, with the aim to achieve the better final properties. All composites produced display good thermal and mechanical properties with glass transition in the range of HT resins (<i>T</i><sub>g</sub> > 150 °C, E’ =26 GPa) for the carbon fiber-based composites. The natural fiber-based composites display slightly lower performance that is nonetheless good compared with standard composite performance (<i>T</i><sub>g</sub> about 115–120 °C, E’ = 7–9 GPa). The present results thus pave the way to the application of adenine as hardener system for composites production.https://www.mdpi.com/2073-4360/12/12/3054adenineepoxy resinsbiobased hardenerrecycled carbon fibersjute fibersflax fibers
spellingShingle Stefano Merighi
Laura Mazzocchetti
Tiziana Benelli
Loris Giorgini
Adenine as Epoxy Resin Hardener for Sustainable Composites Production with Recycled Carbon Fibers and Cellulosic Fibers
Polymers
adenine
epoxy resins
biobased hardener
recycled carbon fibers
jute fibers
flax fibers
title Adenine as Epoxy Resin Hardener for Sustainable Composites Production with Recycled Carbon Fibers and Cellulosic Fibers
title_full Adenine as Epoxy Resin Hardener for Sustainable Composites Production with Recycled Carbon Fibers and Cellulosic Fibers
title_fullStr Adenine as Epoxy Resin Hardener for Sustainable Composites Production with Recycled Carbon Fibers and Cellulosic Fibers
title_full_unstemmed Adenine as Epoxy Resin Hardener for Sustainable Composites Production with Recycled Carbon Fibers and Cellulosic Fibers
title_short Adenine as Epoxy Resin Hardener for Sustainable Composites Production with Recycled Carbon Fibers and Cellulosic Fibers
title_sort adenine as epoxy resin hardener for sustainable composites production with recycled carbon fibers and cellulosic fibers
topic adenine
epoxy resins
biobased hardener
recycled carbon fibers
jute fibers
flax fibers
url https://www.mdpi.com/2073-4360/12/12/3054
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AT lauramazzocchetti adenineasepoxyresinhardenerforsustainablecompositesproductionwithrecycledcarbonfibersandcellulosicfibers
AT tizianabenelli adenineasepoxyresinhardenerforsustainablecompositesproductionwithrecycledcarbonfibersandcellulosicfibers
AT lorisgiorgini adenineasepoxyresinhardenerforsustainablecompositesproductionwithrecycledcarbonfibersandcellulosicfibers