Degradation of Nylon 6,6 and Glass Fiber Reinforced Nylon 6,6 by Aqueous Solutions of Ethylene Glycol and Calcium Chloride

Glass fiber reinforced nylon 6,6 (GFNY66) composites widely used for automotive applications are highly deteriorated when contacted repeatedly with aqueous solutions of ethylene glycol (EG) and calcium chloride resulting in reduced molecular weight, disruption of intra- and intermolecular hydrogen bonding and interfacial failure between glass fiber and nylon 6,6 (NY66) matrix. Hence, it is important to understand clearly the degradation and hydrogen bond breaking mechanism of NY66 and interfacial failure mechanism in GFNY66 in order to improve the mechanical properties of recycled NY66. From ATR-IR spectrum of aq. EG and aq. calcium chloride (CaCl2) treated NY66 specimens, the breakage of intra- and intermolecular hydrogen bonding has been noticed from the shifting of carbonyl stretching band towards lower frequency. The mechanical properties of aq. CaCl2 treated NY66 has been found to be better than that of aq. EG treated NY66 due to lesser reduction in molecular weight for aq. CaCl2 treated NY66 specimens. Among all the specimens, aq. EG treated GFNY66 exhibited pronounced deterioration in mechanical properties, which is associated with more contribution of interfacial failure between glass fiber and NY66.