Polyolefin-polyamide blends

Polyolefin/polyamide blends can be used for a variety of applications where one polymer will enhance the properties of the other polymer. Research on these blends has so far been very fundamental, exploring different possibilities to compatibilize and improve the properties of otherwise very incompatible pol5miers. 

Willis J M and Favis B D (1988) Processing-morphology relationships of compatibilized polyolefin/ polyamide blends. Part I The effect of an ionomer compatibilizer on blend morphology, Polym Eng 28 1416-1426. 

Blends based on polyolefins have been compatibilized by reactive extrusion where functionalized polyolefins are used to form copolymers that bridge the phases. Maleic anhydride modified polyolefins and acrylic acid modified polyolefins are the commonly used modified polymers used as the compatibilizer in polyolefin-polyamide systems. The chemical reaction involved in the formation of block copolymers by the reaction of the amine end group on nylon and anhydride groups or carboxylic groups on modified polyolefins is shown in Scheme 1. 

It is worthwhile to note that chemistry plays a major role in the morphology and control of mechanical properties in complex systems like PPE blends with crystalline polymers, such as polyolefins, polyamides (PA) and polyesters (18). The amount of copolymer formed during the reactive extrusion between functionalised PPE and PA has a significant effect on the impact-strength of blends. The latter levels off only above 10% of copolymer. 

Polyamide -i- Polyolefin Binary Blends (excepting polypropylene)... 

Polyolefin-polyamide melt blends are striking in not only the lack of miscibility, but also the large interfacial tensions between the two melt phases. Investigations of these phenomena in our laboratories (118,124-126) have made numerous studies of these polymer blend systems and found that their phase morphology are quite unstable and trend to coalesce especially under quiescent or low deformation rate conditions. Similar to polyolefin-polystyrene blends, they also show weak interfacial adhesion (118,124,127) (as shown in Fig. 2.9). The mechanical properties of the... 

Functionalized Polyolefins and Aliphatic Polyamide Blends Interphase Interactions, Rheology, and High Elastic Properties of Melts... 

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