Properties of PET fibers with high modulus and low shrinkage (HMLS). I. Yarn properties and morphology

Classical morphological analysis has been performed on novel PET fibers of high modulus and low shrinkage (HMLS). As expected, amorphous orientation controls the degree of shrinkage and tenacity. The uniqueness of these materials is derived from a high “effective” crosslink density which results in a high retractive force during elevated temperature shrinkage and significant stress‐amplification during room temperature extension. Although the morphological origin of the high effective crosslink density is unknown, it is speculated that the interfibrillar regions contribute to the observed behavior by suppressing yielding.