Topic summary
Aramids
Extracted from the Wikipedia article Aramid.
Para-aramids and meta-aramids
Aramids are divided into two main types according to where the linkages attach to the rings. Numbering the carbon atoms sequentially around a ring, para-aramids have the linkages attached at positions 1 and 4, while meta-aramids have them at positions 1 and 3. That is, the attachment points are diametrically opposite each other in para-aramids, and two atoms apart in meta-aramids. The illustration thus shows a para-aramid.