Effects of heat treatment on tensile properties of high-strength poly(vinyl alcohol) fibers

The tensile properties of high-strength poly(vinyl alcohol) (PVA) fibers af ter heat treatment in air, water, and engine oil were studied. The results show that heat treatment in air, water, and engine oil have a different inf luence on the tensile properties of high-strength PVA fibers. After heat tr eatment in air, the fibers possess excellent heat stability of the tensile properties. But in water, especially in hot water, the tenacity, Young's mo dulus, and specific work of rupture of the fibers decrease, while the elong ation at break of the fibers increases. Similarly, engine oil has a signifi cant influence on the tensile properties of the fibers. When the temperatur e of engine oil is above 120 degrees C, the tensile properties of the fiber s decrease drastically. We also discuss the influence of heat, water, and e ngine oil on the tensile properties of high-strength PVA fibers in relation to the structure of the fibers. (C) 2000 John Wiley & Sons, Inc.