IF MOHINI SAIN HAD HIS WAY, CARS OF THE FUTURE MAY BE FITTED WITH TOUGH, durable and completely biodegradable bumpers made of hemp.
Sain, a professor in U of T's Faculty of Forestry and Department of Chemical Engineering and Applied Chemistry, creates biocomposites from processed plant fibres. His latest research describes a way to create a material from hemp (a member of the cannabis family) and other agro-fibres such as flax, kenaf, wheat straw and root crops that are both strong and lightweight. "We hope to develop this technology for automotive parts like instrument panels and bumpers, as well as structural applications for buildings and sports equipment and, ultimately, medical devices such as cardiac devices and blood bags," says Sain.
His team treated stalks of hemp with chemicals to break down the "glue" that holds clumps of fibres together. The plant material was then combined with synthetic plastics and exposed to heat and pressure. This compresses the material into a variety of shapes, producing a consistent, durable product with significant resistance to environmental factors such as sunlight and temperature. However, if the plant material is mixed with plastics made from soy beans, corn-based bioplastics or any other natural polymers, the researchers can create tough biocomposites that are completely biodegradable. While these studies used hemp and flax, the process also works with kenaf, jute, wheat and corn straws.
The plant material is meant to compete with tough synthetic materials such as glass fibres, and Sain hopes to create a plant-based biocomposite that is as strong as steel by incorporating micro- and/or nano-sized natural fibres in diverse plastics. In the case of hemp, it has a "springy" characteristic that allows it to absorb energy, making it ideal for applications where crash-resistance is required. The team is already exploring research involving "nanobiocomposite" technology that could someday be used in tissue engineering.
As a founding member of the newly-formed Canadian Natural Composites Council, Sain says these green materials could ultimately help Canada reduce its greenhouse gas emissions. "One of the greatest benefits of this technology is that we will not harm our environment by overproducing these natural fibres. It's a step towards reducing petrochemical-based material consumption and living in a bio-based economy."
Sain will be the director of the Centre for Biocomposites at the University of Toronto, slated to open this fall, which will educate people, improve awareness of biomaterials and their applications and create a hub for biocomposite and biomaterials research in Canada. Scientists will collaborate with eight universities and more than 40 researchers from coast to coast, as well as more than two dozen private sector companies and the public sector.
Sain's research is funded by the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council, the AUTO 21 Network of Centres of Excellence, the Ontario Ministry of Agriculture and Food and Materials and Manufacturing Ontario, along with several industry partners.
- By Nicolle Wahl