Researchers announce material innovations

A Japanese semiconductor solutions firm and two university researchers have developed three separate solutions that open the door for new plastic applications.

Tokyo, Japan-based NEC Corporation has developed a new bioplastic made from plant-based feedstock and carbon fiber that has higher heat conductivity than stainless steel. The new plastic is expected to make electronic products more environmentally sound and solve conventional heat release issues.

The creation of a cross-linked structure of carbon fiber through the use of a unique binder in the bio-based polylactic acid (PLA) resin achieves high heat diffusion. According to the company, this also enables good heat conductivity in the plane direction of the PLA resin board, which is conventionally difficult to attain in metal boards.

The product is mainly composed of biomass-based components, and the biomass ratio exceeds 90 per cent.

Recently, small-sized electronics such as cell phones and personal computers have suffered from heat-release issues due to an increase in the amount of heat being generated, but conventional heat-release devices such as fans and sheets are hard to incorporate.

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Meanwhile, a professor at Brooklyn, New York-based Polytechnic University is developing a fuel-latent plastic that can be converted into biodiesel. Gross, the director of Polytechnic University’s National Science Foundation (NSF) Center for Biocatalysis and Bioprocessing of Macromolecules (CBBM), used vegetable oils to develop the new plastic.

He also partnered with biotechnology company DNA 2.0 to develop enzymes that can synthesis and break the fuel-latent plastic down into biodiesel after its use.

Although Gross’s research is not ready for commercialization — the next phase will help develop an efficient low-cost process for manufacturing and conversion — he recently received US$2.34 million in funding from the Defense Advanced Research Projects Agency (DARPA), the central R&D organization for the US Department of Defense.

“We showed DARPA that we could make a new plastic from plant oils that has remarkable properties, which includes being tougher and more durable than typical polyethylenes,” said Gross in a statement. “Additionally, the bioplastic can be placed in a simple container where it is safely broken down to liquid fuel.”

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Dr. Yueh-Lin (Lynn) Loo, an associate professor of chemical engineering at the University of Texas at Austin, has modified a plastic so that its ability to carry an electrical current can be altered during manufacturing.

Loo studied polyaniline because of possible applications in flexible, inexpensive wiring, and combined it with a chemical that gives it conductivity. The resulting research, which was recently published in the Journal of Materials Chemistry, found that the plastic’s conductivity could be increased by up to six-fold based on the version of the chemical added to the polyaniline.

According to Loo, altered polyaniline has various advantages over common metals like gold and copper. Modified polyaniline can be manufactured in room temperatures without vacuum chambers, compared to the manufacturing conditions required for expensive metals.

Since submitting her research, Loo has developed a version of polyaniline that has 10 times higher conductivity than before. However, this level of conductivity still does not rival copper, which is used for high-speed interconnections.