Polyvinyl chloride
Waldo Semon
Waldo Semon did not invent PVC. He invented how to make it behave. His 1926 method — blending it with additives like dibutyl phthalate — converted a brittle, unprocessable polymer into something elastic and non-adhesive. That enabled Koroseal: a salt-coke-limestone-derived polymer whose consistency could be set deliberately. It did not fix PVC’s thermal instability or environmental persistence. Its real innovation was tunability — proving synthetic polymers could be governed, not just discovered.