QUV Accelerated Aging Effects on the Structure and Properties of Polyether Polyurethane Fibers

Abstract

Abstract This paper presents an experimental study about the effects of UV irradiation on polyether polyurethane (PU) fibers investigated by FTIR, SAXS and AFM, and the multiple mechanism is finally proposed.The results show that, at low UV irradiation (0.6W/m2, 0.9W/m2), the mechanism responsible for UV degradation of polyether PU fibers could be described as a primary reaction causing the break up of chemical bonds and forming the new quinone structure, along with a secondary reaction to explain hydrogen peroxide formed in the presence of UV irradiation, water and oxygen environment which promotes QUV aging by providing loose structure of polyether PU fibers. Moreover, the micro phase separation is promoted for a parallel reaction occurred to produce new polyether PUs and more compact micro domains by the residual isocyanate in pre-polymerization stage and alcohols formed under QUV aging. Under higher UV irradiation (1.2W/m2, 1.5W/m2), in addition to the primary reaction, a tertiary reaction showing the re-polymerization occurred under accumulation of aging products (carboxylic acids and alcohols) is also considered as the mechanism, while the secondary reaction would be inhibited for the peak assigned to H2O2 is not observed. Also, this decreases micro phase separation of polyether PU fibers for the primary reaction is dominant.