From cannabis to carburetor

U of T prof makes autoparts from hemp

Amid the clutter of textbooks‚ journals‚ papers and reams of notes in the office of Dr. Mohini Sain sit a car door‚ a bus seat‚ an instrument panel‚ a deck plank‚ and a car bumper—all of them made from hemp.

Dr. Sain is a professor in U of T’s Faculty of Forestry and the Department of Chemical Engineering and Applied Chemistry‚ and has conceived of more things to do with hemp than you can think of to do with the strongest (mechanically speaking) of hemp plants‚ cannabis. “We look at the potential for hemp in automotive parts‚ sports apparel‚ the furniture industry‚ aeronautics‚ and the medical industry‚” Dr. Sain said. You can make skis‚ dashboards‚ bumpers‚ I beams‚ cross ties for railroad tracks‚ canoes‚ tennis rackets‚ basketball stands‚ car door panels‚ roof shingles and a myriad of other things from the materials that he and his collaborators have developed. And hopefully‚ in the very near future‚ we will be able to make biomedical supplies‚ like bloodbags‚ and even airplane parts from hemp.

“Our direction is to move away from fossil fuel based synthetics to more natural alternatives‚” said Dr. Sain.

How does he manage to turn fluffy green cannabis plants into car siding capable of withstanding a full–on impact? A long chemical process allows Dr. Sain to extract long‚ thin strands of pure starch‚ or cellulose (a long chain of sugars) from hemp. In the plant‚ many of these strands put together make a hemp fiber. By first isolating individual strands and then reassembling them back into fibers‚ chemists make fibers with as few defects as possible‚ making them much stronger. They can also control the length and diameter of the strands—the longer and thinner the strand‚ the stronger it is.

By enmeshing hemp fibers into a matrix of glue‚ Dr. Sain has been able to create plastics almost identical to conventional plastics (save for their brown colour). The glue could be synthetic‚ or it could be natural—there are already many bioplastics made from soy or corn being used. Dr. Sain is particularly interested in producing construction materials from a glue of wood resin interwoven with hemp fibers. The wood resin could easily come from leaf litter and forest floor debris‚ he said. Fewer trees would have to be cut down than are needed to support our current construction business.

The technology is not entirely new—for years Dr. Sain and many other scientists have been making biomaterials‚ or industrial materials made from natural products. You may even have already ridden in a car made with hemp parts. Dr. Sain’s fiberglass–like hemp material has been used in car door siding for two years now. Transit seats made from 100 per cent hemp with a polyester glue are already in widespread use. “The first generation of biomaterials has already been in use for several years. For example‚ in the construction industry‚ if you go to places like Home Hardware‚ you can find decking materials made from synthetic plastics combined with wood fibers or rice husks‚” said Dr. Sain.

Dr. Sain is working towards improving the strength and durability of these materials‚ and devising even more ways of using hemp commercially. He hopes that he will be able to create steel interfused with hemp. Weaving hemp fibers into steel makes the metal stronger‚ which would allow auto manufacturers to lower the thickness of the steel they use. Not only would this mean using less steel‚ but it would also mean making a much lighter car that would use far less fuel‚ costing less for everyone and creating less pollution. Win–win.

With such a development you could literally build a car from the inside out with hemp–the steel frame and body‚ hubcaps‚ bumpers‚ instrument panel‚ seats‚ and seat coverings all could be made with hemp.

Dr. Sain is also optimistic that within a few years we will have blood bags and other biomedical supplies made from hemp. Syringes and gloves and other medical gear‚ by and large‚ cannot be reused‚ but ones made from hemp would be 100% biodegradable. He and his associates will first have to ensure however that these biodegradable materials will be safe for human use. No matter how fond you are of environmentally friendly alternatives‚ an IV bag that slowly disintegrates into your drip and your veins is not a pleasant thought.

Hemp alternatives not only make environmental sense‚ says Dr. Sain‚ they make economic sense. “We look to make environmentally and economically sustainable materials.” By creating industrial products with hemp‚ “you can bring some of this value back to the farmers who grow the plants‚ and then you can develop some small industries and employ some people to make these materials. You not only give added value to the farmers‚ you also get additional employment.

“This is a public issue. That’s why we are scientists—we are interested in accepting the challenges and finding solutions. We meet the concerns of the public.”