A special family of polyesters are polycarbonates. hydrocarbon
backbones which contain ester linkages, hence the name. The
structure in the picture is called poly(ethylene terephthalate),
or PET for short, because it is made up of ethylene groups and
terephthalate groups (duh!). I realize that terephthalate is not
the kind of word most English-speaking mouths are used to
saying, but with practice you should be able to say it with only
a slight feeling of awkwardness when it rolls off your tongue.
The ester groups in the polyester chain are polar, with the
carbonyl oxygen atom having a somewhat negative charge and the
carbonyl carbon atom having a somewhat positive charge. The
positive and negative charges of different ester groups are
attracted to each other. This allows the ester groups of nearby
chains to line up with each other in crystal form, which is why
they can form strong fibers. The inventor who first discovered
how to make bottles from PET was Nathaniel Wyeth. He's the
brother of Andrew Wyeth the f