Organic Polymer can be used in place of Regular Polymer. Be aware, however, that this Organic version of Polymer will spoil rapidly. This means that you must use it soon after harvesting it.
Only Kairuku yield Organic Polymer. They are found exclusively in the Snow Biome on or near Ice Bergs or the shoreline. Be aware that this organic version of Polymer will spoil in 30 minutes if it is not used.