What are the differences between aramid 1313 and 1414?

Aramid 1313 and 1414: Two Critical Aromatic Polyamide Fibers

Aramid 1313 and 1414 represent two essential types of aromatic polyamide fibers (Aramid fiber), with their numerical designations reflecting distinct chemical structural differences. The specific meanings are as follows:

1. Aramid 1313 (Meta-aramid, meta-oriented aramid)

Chemical Structure:
Formed by polymerization of isophthaloyl chloride and m-phenylenediamine, where the amide linkages (—CO—NH—) connect to the benzene ring at the meta-positions.

Nomenclature:

• "13" indicates the amide bonds are attached at the *1,3-positions* (meta-positions) of the benzene ring.

• The dual "13" signifies that both monomers (diamine and diacid chloride) feature meta-oriented bonding.

Properties:

• Heat-resistant (long-term service temperature ~200°C), flame-retardant, and electrically insulating.

• Lower mechanical strength compared to 1414.

Applications:

• Firefighting gear, high-temperature filtration materials, electrical insulation paper (e.g., DuPont’s Nomex®).

2. Aramid 1414 (Para-aramid, para-oriented aramid)

Chemical Structure:
Polymerized from terephthaloyl chloride and p-phenylenediamine, with amide bonds linked at the para-positions of the benzene ring.

Nomenclature:

• "14" denotes amide bonding at the *1,4-positions* (para-positions).

• The dual "14" reflects para-oriented bonding in both monomers.

Properties:

• Ultra-high strength, high modulus, and impact-resistant (tensile strength ~5× that of steel).

• Slightly inferior heat resistance compared to 1313.

Applications:

• Bulletproof vests, tire cords, optical fiber reinforcement (e.g., DuPont’s Kevlar®, Teijin’s Twaron®).

Key Terminology

Comparative Summary

This classification system highlights how molecular orientation (meta vs. para) dictates material performance, enabling tailored applications across industrial, military, and aerospace sectors.