Definition of diastereomer. : a stereoisomer of a compound having two or more chiral centers that is not a mirror image of another stereoisomer of the same compound â compare enantiomer.
Most perennial weeds such as Johnsongrass. are also suppressed although vigorous plants or heavy in-. festations may lift plastic. Perennial sedges, and to a lesser. extent, grasses can puncture sheet mulches as the weeds. emerge from the soil, resulting in inadequate control.
Plasticisers. A plasticiser is a substance which when added to a material, usually a plastic, makes it flexible, resilient and easier to handle. Early examples of plasticisers include water to soften clay and oils to plasticise pitch for waterproofing ancient boats.he PVC polymer molecules and the plasticizer molecules are electrically attracted to each other, and the non-polar parts widen the distance among the polymer molecules to keep softness. PVC products which are softened by plasticisers are called soft (flexible) PVC products.