Poly -liquid-crystalline tensile strength

More recently, Wilczynski, Ward and Hine [24] have proposed an inverse calculation method where the elastic constants of a fibre can be estimated from fibre resin composite and the elastic constants of the resin. The method was confirmed by measurements on polyethylene/epoxy and carbon fibre/epoxy resin composites. It has been applied [25] to the determination of the elastic constants of a new organic fibre, poly 2,6-dimidazo[4,5-6 4 5 -e]pyridinylene l,4(2,5-dihydroxy)pheny-lene (PIPD). This fibre is a lyotropic liquid crystalline fibre with a very high Young s modulus of 285 GPa and a much higher tensile strength (5.21 GPa) and compressive strength (5OOMPa) than other polyaramid fibres such as Kevlar. 

The liquid crystalline-forming polymer, poly(l,4-benzamide), has a modulus and tensile strength still higher than the ultradrawn polyethylene. The properties of poly(l,4-benzamide) are compared with the well-known fibers nylon and rayon. The latter are much softer but are more extensible. 

---