Finding a future for postconsumer plastics
Wouldn't it be nice if the common plastic polypropylene could be recycled into part of a roofing material? To accomplish this, the plastic needs to be made less stiff, or the roof will be too fragile. In his thesis, Justin Bulten investigates how the use of a second material can change the properties of the plastic to give it the desired stiffness. This succeeded partially, but not sufficiently so. Bulten then investigated a second pathway that proved even more challenging, and which did even less to make the plastic less stiff than the first pathway.
Next, Bulten shifted his perspective. The plastic would not be the sole component in the roofing material, but would be mixed in with another material, bitumen. Instead of keeping the focus solely on the plastic, Bulten started testing how to make the mixture of these materials less stiff. Though unable to prepare a mixture that was flexible enough, he did find another way to steer the properties.
Combining all pathways of this exploration, one might be able to find the sweet-spot to ensure the correct properties of the roofing material. That would go a long way to address our waste problem for one of the most common plastics in use.