|
Abstract
|
A new approach for compatibilizing polyamide-66 (PA-66)/high density polyethylene blends using polyamide-grafted ethylene vinyl alcohol copolymer (EVOH-g-PA) is presented in this study. EVOH-g-PA was prepared through sequential reactions of adipoyl chloride and hexamethylenediamine with hydroxyl groups of EVOH chains. Two different EVOHs having 44 and 88 mol% ethylene monomer were modified to obtain EVOH44-g-PA and EVOH88-g-PA, respectively. The efficiency of modified EVOHs in compatibilization of PA/PE blends were evaluated by morphological observations as well as rheological and crystallization measurements. The PE droplets in the PA matrix became finer when EVOH44-g-PA or EVOH88-g-PA were incorporated in the blends. However, the compatibilizing effects of EVOH88-g-PA were more pronounced due to higher ethylene content in the primitive EVOH chain promoting its diffusion into the PE droplets. The complex viscosity of compatibilized blends were also enhanced showing the improved adhesion between PA and PE phases. A reduction in the crystallization temperatures (Tc) of PA matrix was noticed upon inclusion of modified EVOHs which was associated with the lowered nucleating activity of the interface due to decreased interfacial tension in the compatibilized blends. Eventually, the results revealed the opportunity of using EVOH-g-PA as a compatibilizing agent in the PA/PE blends.
|