By Kit Chapman2021-01-11T09:14:00+00:00 From their colonial roots to future alternatives, Kit Chapman looks at the chemistry of natural elastomers In the jungles of Brazil, near to where the dark waters of the Rio Negro meet the vast, muddy flow of the Amazon, a worker scrapes expertly at a tree. The trunk is already stripped of bark in places, scarred by countless previous wounds that have left a criss-crossed mess of scratches, but with careful management years of useful life still remain. Pulling away his curved blade, a cross between a carving knife and a machete, the worker points to the...