Biodegradable plastic cups
Infrared spectroscopy (green line) of a biodegradable 'plastic' cup, seen in the centre of the photograph, compared with two samples of conventional clear plastic food-wrapping boxes (red and brown line spectra).
The cup is made from corn starch converted to polylactic acid (PLA): see: en.wikipedia.org/wiki/Polylactic_acid
The PLA shows a rich blue fluorescence under LW (UVa) light in contrast with the plastic that glows a pale greenish white.
Biodegradable plastic cups
Infrared spectroscopy (green line) of a biodegradable 'plastic' cup, seen in the centre of the photograph, compared with two samples of conventional clear plastic food-wrapping boxes (red and brown line spectra).
The cup is made from corn starch converted to polylactic acid (PLA): see: en.wikipedia.org/wiki/Polylactic_acid
The PLA shows a rich blue fluorescence under LW (UVa) light in contrast with the plastic that glows a pale greenish white.