Premium
Drawing in high pressure CO 2 —a new route to high performance fibers in memory of late Roger Porter
Author(s) -
Hobbs Terry,
Lesser Alan J.
Publication year - 2001
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10716
Subject(s) - materials science , crystallinity , composite material , polyethylene terephthalate , ultimate tensile strength , polyethylene , polymer , supercritical fluid , ultra high molecular weight polyethylene , high pressure , modulus , nylon 66 , nylon 6 , engineering physics , polyamide , chemistry , organic chemistry , engineering
In this paper, we introduce a new draw technique for polymer orientation and apply it to different polymer fibers: poly(ethylene terephthalate) or PET, nylon 6,6, and ultra‐high molecular polyethylene (UHMWPE). In this technique, a polymer is drawn uniaxially in supercritical CO 2 using a custom high‐pressure apparatus. This technique can be used in replacement of a traditional drawing process or as a post‐treatment process. With PET, the technique is not effective at temperatures at or below 130°. In contrast, the process is highly effective for nylon 6,6 where CO 2 drawn fibers show significantly higher crystallinity and orientation along with improved mechanical properties. While the fibers are plasticized, the drawability of the fibers is only slightly dependent on temperature. High pressure CO 2 drawing of ultrahigh molecular weight polyethylene (UHMWPE) fibers is equally effective. Commercial high performance fibers can be drawn up to a ratio of 1.9 in asecond stage, resulting in large increases in tensile modulus and small improvements in tensile strength.