Plastic clothes pegs that last 20 or 30 years may be just around the corner after research by scientists at the Australian National University (ANU).

The scientists found most plastic molecules are flawed, causing items exposed to the sun over long periods to degrade.

Associate Professor Michelle Coote says the research also points to how to make plastic that does degrade quickly.

"We know now what makes degradation occur rapidly so we could actually engineer plastics to do that quite quickly," she said.

"We're not the first people to work out how to engineer biodegradable polymers but we think the ideas we've uncovered could be used a lot more broadly than they currently are."

Associate Professor Coote says by eliminating the flaws in plastic, items like clothes pegs could be made to last much longer.

"It would depend but you could imagine something lasting 20 or 30 years instead of six months. That would be the idea," she said.