Researchers at the University of Illinois have developed a new polymer curing process that could drastically reduce the cost, time and energy needed to manufacture FRP. The researchers findings indicate that the new polymerization process uses 10 orders of magnitude less energy and can cut two orders of magnitudes of time over the current manufacturing process.
According to the researchers, the process of curing just one section of a large commercial aircraft such as Boeing’s 787 Dreamliner can consume over 96,000 kilowatt-hours of energy and produce more than 80 tons of CO2, depending on the energy source. The researchers believe their new curing method would lower the energy requirement for the same part to just 9.6 milliwatt hours.
“This development marks what could be the first major advancement to the high-performance polymer and composite manufacturing industry in almost half a century,” said aerospace engineering professor and lead author Scott White.
The research, which is being supported by the U.S. Air Force, focuses on a new process called frontal polymerization that allows the researchers to control chemical reactivity to economize the polymer-curing process. The first step in the process is to pre-shape a solution or gel of a monomer called dicyclopentadiene (DCPD) or a DCPD-fiber mixture. The researchers then use a heat source to initiate polymerization of the pre-shaped material. Once initiated, the monomer has enough internal energy to polymerize itself into a thermoset product, with no autoclave needed.
The process is called frontal polymerization because the reaction moves quickly through the monomer resin or monomer-fiber mixture along a line, or front, like a rapidly moving weather system or military formation. Frontal polymerization of DCPD produces high-performance, cross-linked thermoset polydicyclopentadiene (pDCPD) polymers or polymer composites.
“By touching what is essentially a soldering iron to one corner of the polymer surface, we can start a cascading chemical-reaction wave that propagates throughout the material,” said White. “Once triggered, the reaction uses enthalpy, or the internal energy of the polymerization reaction, to push the reaction forward and cure the material, rather than an external energy source.”
The team has demonstrated that this reaction can produce safe, high-quality polymers in a well-controlled laboratory environment. They envision the process accommodating large-scale production due to its compatibility with commonly used fabrication techniques like molding, imprinting, 3-D printing and resin infusion.
To read the researchers’ complete findings, visit https://www.nature.com/articles/s41586-018-0054-x.