LIQUID CRYSTAL POLYMERS
PBO (Zylon®)
PBO (Poly (p-phenylene-2, 6-benzobisoxazole)) is a rigid-rod lyotropic liquid crystal polymer developed by Japan-based Toyobo under the trade name Zylon®. PBO is a gold fiber with an initial modulus that is significantly higher than other high modulus yarns, including aramids. Among PBO’s desirable properties are high thermal stability, low creep, high chemical resistance, high cut and abrasion resistance, and excellent resistance to stretch after repeated folding. PBO is also quite flexible and has a soft hand. Less desirable is PBO’s poor resistance to both UV and visible light, which, unless a UV film is used, greatly reduces the working life of the sail.
Vectran®
Vectran is a polyester-based high performance LCP (liquid crystal polymer) produced by Hoechst Celanese. It is naturally gold in color and has a modulus similar to Kevlar 29, but suffers negligible strength loss with flex. This is a benefit in endurance applications and for cruising sails where durability is key. Additional advantages of Vectran fiber include zero creep, high chemical and abrasion resistance and high tensile strength. Although it was initially though that Vectran’s UV resistance was lower than those of the Aramids or of Spectra, it has been shown that, over an extended test period, the UV degradation of Vectran levels off after roughly 400 hours of exposure, while the Aramids and Spectra® continue to degrade. To learn more about the latest developments in Vectran sailcloth, refer to A Case for Vectran. And, for technical information about the fiber, click here.
