Differences between tensile testing standards for aromatic polyamide fibers
Aromatic polyamide fibers are fibers composed of linear macromolecules formed by aromatic groups linked by amide or imide bonds. At least 85% of the amide or imide bonds are directly connected to two aromatic rings, and when imide bonds are present, their percentage does not exceed that of amide bonds. Based on the substitution position of the aromatic groups, aromatic polyamide fibers are further divided into para-aramid fibers and meta-aramid fibers. Para-aramid fibers have a linear molecular chain arrangement; a typical product is poly(p-phenylene terephthalamide) fiber, abbreviated as para-aramid (also known as aramid 1414 in my country). Meta-aramid fibers have a zigzag molecular chain arrangement; a typical product is poly(m-phenylene isophthalamide) fiber, abbreviated as meta-aramid (also known as aramid 1313 in my country). This article mainly introduces and compares the currently implemented testing standards for meta-aramid and para-aramid fibers, analyzing the differen...