Moderate Temperature Curing of Plant Oils with Bismaleimides via the Ene Reaction

Significance Statement

Bismaleimide systems are desirable resins for reinforced composites necessary for high-performance applications, for instance, structural laminates, aerospace, elastomers, and printed circuit boards. The advantages of these systems include high mechanical and thermal stability, constant electrical characteristics over a wide range of temperature, and superior processability.

For commercial applications, bismaleimides are normally cured with petroleum comonomers such as polyimides, polyesters, and epoxies. This polymerization curing process is not 100% complete and the untreated monomers can leach out of the polymers, which has environmental as well as health implications. Moreover, their longer biodegradation times add to the list of disadvantages of bismaleimides.

Luckily, plant oils or fatty acids present a better platform of resins for reinforced composites that are bio-renewable. University of Akron researchers proposed the synthesis of cross-linked thermosets by the reaction of plant oils and fatty acids with bismaleimides through an ene reaction. In their work, they presented the functionalization and characterization of thermosetting resins extracted from plant oils using three bismaleimides. Their work is now published in peer-reviewed journal, Industrial & Engineering Chemistry Research.

In their experiments, soybean and linseed oils were cured in 1,1′-(methylene-di-1,4-phenylene) bismaleimide and oligomeric bismaleimides to yield bio-based thermoset polymers.

The authors found that, one molecule of the soybean oil corresponded to approximately 4.6 carbon-carbon double bonds. In a similar fashion, one molecule of linseed oil corresponded to 6.0 carbon-carbon double bonds. During the heating scan, 1,1′-(methylene-di-1,4-phenylene) bismaleimide melted and was followed by an exothermic curing between the soybean oil and the bismaleimide. The outcomes demonstrated that the curing reaction in bulk was determined by the melting temperature along with fluidity of the bismaleimide.

No transitions were noted in the subsequent heating scan indicating that the ene curing was completed by the end of the first scan. Although linseed oil, soybean oil, and all the three bismaleimides, are soluble in chloroform, dimethyl sulfoxide and methylene chloride, all their cured products are insoluble in these as well as other organic solvents. This shows that the cured products cross-linked.

This study found that plant oils could be cured with bismaleimides by the ene reaction at moderate temperatures without modifying the oils and without using solvents or catalyst. Therefore, this green technology of curing plant oils with bismaleimides by the ene reaction offers an improved approach for manufacturing bio-based thermoset polymers and reinforced composites with superior thermal stability and mechanical properties important for commercialization.

Acknowledgement: This work was initiated through a sub-contract from Premix Inc.’s SBIR Phase II Award 1256123.

Curing of Plant Oils with Bismaleimides via Ene Reaction-Advances in Engineering

About the author

Coleen Pugh is a Professor and the Chair of the Department of Polymer Science at The University of Akron. She served as an Associate Editor for the ACS journal, Macromolecules, from 1999 to 2011. She also established a National Science Foundation Research Experience for Undergraduates (NSF-REU) Site for Polymer Science and Polymer Engineering in 2004, and directed it through 2009.

Prior to joining UAkron in 1998, she spent almost five years as an Assistant Professor of Chemistry and of Macromolecular Science and Engineering at The University of Michigan, after spending 11 months as a Visiting Assistant Professor of Chemistry (sabbatical replacement) at Carnegie Mellon University. Her undergraduate degrees are in Chemistry and Textile Science (Univ. of California, Davis); her graduate degrees are in Macromolecular Science from Case Western Reserve University; and her postdoctoral research was in Organometallic and Polymer Chemistry at MIT.

Professor Pugh is a synthetic organic polymer chemist. She is a fellow of the AAAS, and received NSF’s Young Investigator Award in 1994 and a Special Creative Invention Award in 2006.

About the author

Brinda Mehta received her B.Eng. degree in Chemical Engineering from University of Mumbai, India (D. J. Sanghavi College of Engineering) in 2006 and her M.S. degree in Material Science and Engineering from Rochester Institute of Technology (RIT), in 2010. She is a Ph.D. graduate from the University of Akron’s Department of Polymer Science. Her Ph.D. research was under the tutelage of Dr. Coleen Pugh at the University of Akron.

While at the University of Akron, she received an Ohio Rubber Group graduate student award in 2013 and a scholarship from Ohio Soybean Council Foundation for the academic year 2014-2015. Currently, Brinda is working for Carlisle Construction Materials as a R&D Chemist. Her hobbies include reading, travelling and cooking.

About the author

In 1983, Dr. Mark Soucek obtained his B.S. in Chemistry from Eastern Illinois University, and a M.S. from Illinois State University in 1986. In 1990, he obtained his Ph.D. from University of Texas at Austin. From 1990 to 1993, he was a NRC Post-Doctoral Fellow at NASA-Langley Research Center. From 1993 through 2001, Dr. Soucek was an Assistant and then Associate Professor at North Dakota State University in the Department of Polymers & Coatings focusing his research on Coatings Science. In 2001, Dr. Soucek joined the Polymer Engineering Department at the University of Akron and while at UA being promoted to full Professor.

Dr. Soucek also has relations with the University de Maine in LeMans France, appointed as guest professor at Wuhan University of Technology, Adjunct Professor at Beijing University of Chemical Technology, and University Ljubljana/PoliMat in Slovenia.

Since started his academic career in 1993, and has won many awards in the coating field including Tess award for Coatings, 3 Roon awards, an UV-innovation award, a Gordon award, and a SSPC Editor’s award and 2016 ACS Tess award for Coatings. He has run many coating symposium including three SOS at the University of Akron.

He has served as President, Vice-President, and Treasurer of the Cleveland Coating Society. Dr. Soucek has also run and participated in a number of symposium for the ACS and is currently a PMSE member. He presently has >140 research papers published all in coating science. Outside interests: Married with children, dancing and fishing.

About the author

Paula Watt is the Director of Outreach for the College of Polymer Science and Polymer Engineering at the University of Akron. She joined the University in 2015 after 30 years of industrial research and technical management experience in the polymer industry. She has a Ph.D. in Polymer Science from the University of Akron, an M.S. in Macromolecular Science from Case Western Reserve and a B.S. in chemistry from the University of Pittsburgh. Paula has authored numerous technical publications including two book chapters. She has prepared winning grant proposals and has been Principle Investigator for multiple industry/university collaborations.

Paula served as the Industrial Advisory Board Chair for Kent State Ashtabula’s Technology Department, as Chairman of the Industrial board of EPIC’s Composites Center of Excellence and on the Polymer Ohio Board of Directors. She also served on the ACMA Educational and Biocomposites sub-committees, as a Business Mentor for a UA I-corp sites team, on NSF SBIR proposal review committees and she has been an adjunct professor at Kent State University.


Brinda Mehta1, Paula Watt1, Mark D. Soucek2, and Coleen Pugh1. Moderate Temperature Curing of Plant Oils with Bismaleimides via the Ene Reaction. Industrial & Engineering Chemistry Research, volume 55 (2016), pages 11727-11735.

Show Affiliations
  1. Departments of Polymer Science, The University of Akron, Akron, Ohio 44325-3909, United States
  2. Departments of Polymer Engineering, The University of Akron, Akron, Ohio 44325-3909, United States


Go To  Industrial & Engineering Chemistry Research

Check Also

Synthesis of Functionalized Medium-Sized trans-Cycloalkenes by 4π Electrocyclic Ring Opening/Alkylation Sequence - Advances in Engineering

Synthesis of Functionalized Medium-Sized trans-Cycloalkenes by 4π Electrocyclic Ring Opening/Alkylation Sequence