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.
Vinyl Fabric Types. Plasticizer -- a chemical polymer -- added to polyvinyl chloride during the manufacturing process becomes vinyl upholstery material, which may or may not have a fabric backing. Manufacturers basically make three kinds of vinyl fabrics: nonbacked vinyl, nonexpanded and expanded vinyl.