A NOVEL TECHNIQUE TO DETECT SMALL MOLECULES OF LOW CONCENTRATION IN POLYMER BLENDS BY RUO_4 STAINING

摘要

The presence and distribution of a trace amount of small molecules, which can be the by-product from slight degradation of blend components during processing or a residual reagent added in reactive processing, are valuable information in polymer blends. However, it is often difficult to discern these substances using normal methods. Low concentrations of butannaldehyde in PC/PBT blends and free residual amine in TPU/PO blends are detected using a RuO_4 staining technique under a scanning electron microscope. Fine grains, which are formed by the reaction of RuO_4 with them, are observed, both on the surface and in the bulk of the two polymer blends after the staining.