PET-Fibers



In-situ reinforcement of PET monofilaments with new non-crystalline liquid crystalline polyesters
	Project description Poly(ethylene terephthalate) (PET) fibers are employed in industrial applications such as tire cords, composites, belts, and textiles. For these applications an improvement in fiber modulus without sacrificing tenacity accompanied by a minimal increase in manufacturing costs would be readily accepted by industry. One concept of PET fiber reinforcement is the formation of in-situ composites with thermotropic liquid crystalline polyesters (TLCP). The objective of the work in this research project was the evaluation of a newly developed amorphous TLCP as an in-situ reinforcement component in PET blend fibers. A typical fibrillar microstructure of the TLCP for as-spun fibers was found in SEM (figure left) investigations. The modulus of hot-drawn blend fibers blend showed a modest increase in modulus of about 22 % to 22.6 GPa at 1200 MPa tenacity and a load level 3 wt% was determined.
The SEM micrograph above shows a TLCP blend fiber obtained by blending PET with 10wt% of a special designed TLCP. The LCP phase is visible in long extended fibrills which are responsible for the reinforcing effect.
Equipment used in this project:
Retsch ZM 100 Ultra Mill Carver 25 ton press High Shear Twin Screw Mixer Randcastle 1/4-inch "Microtruder" with fiber die SWO Capillary Spinner "Meltflixer"	Drawing rig INSTRON Universal Tester Olympus BX60 Polarizing Microscope Rheology, X-Ray and SEM Facilities
Publications and Patents: W. Grasser, R. Giesa, and H.-W. Schmidt, Polymer, 42(21), 8517- 27 (2001) Fibers spun from poly(ethylene terephthalate) blended with a thermotropic liquid crystalline copolyester with non-coplanar biphenylene units W. Grasser, R. Giesa, and H.-W. Schmidt, Polymer, 42(21), 8529-40 (2001) Thermotropic liquid crystalline copolyesters with non-coplanar biphenylene units tailored for blend fiber processing with PET R. Giesa, S. Joslin, D. Melot and R. J. Farris, Polymers & Polymer Composites 3(5), 333 (1995). Properties of Fibers Spun from Blends of a Thermotropic Liquid Crystalline Block Copolymer with Poly(ethyleneterephthalate) R. Giesa, S. Joslin and R. J. Farris, Polymer 35, 4303 (1994). Thermotropic Liquid Crystalline Polymers with flexible Moieties blended with Poly(ethylene terephthalate) Liquid Crystal Copolymer Containing Alkoxy-Substituted Para-Phenylene Terephthalate Groups Inventors: A. Tendolkar, S. Narayan, S. W. Kantor; R. W. Lenz, R. J. Farris, S. L. Joslin and R. Giesa, WO 9409194 (1994) Polyester Fibers Containing Liquid Crystal Copolymers Containing Alkoxy-Substituted para-Phenylene Terephthalate Groups Inventors: R. J. Farris, S. L. Joslin and R. Giesa, US-Patent 5,232,778 (August 1993)
Complete publication list