Effect self-compatibilization

The described peculiarities of MFCs can be expected and realized when the blend partners are condensation polymers or, at least, functionalized polyolefins. The latter restriction however, concerns only the self-compatibilization effect but by no means the basic principles of MFC manufacturing, i.e., MFCs can be prepared also from polyolefin partners provided the basic temperature requirements for their preparation are satisfied. 

These reactions result in the formation of a copolymeric layer at the interface, playing the role of a compatibilizer, i.e., one deals with a self-compatibilization effect in that there is no need to introduce an extra synthesized copolymer of the blend components, as in the common approach [5]. Compatibilization can be effective only in the initial stages of chemical interaction. During prolonged thermal treatment, the reaction goes to completion and finally involves the entire amount of the molten blend components in the formation of block copolymers, thus transforming the homopolymeric (molten) blend into copolymers. 

First, the compatibDizing copolymer is automatically formed at the interface between the two immiscible polymers where it is needed to stabilize morphology. In contrast, when a compatibilizing copolymer is added as a separate entity to a polymer blend, it must diffuse to the polymer-polymer interface to be effective for promoting morphology stabilization and interfacial adhesion between dispersed and continuous phases. However, that added copolymer may prefer to self-associate in micelles and form a separate phase that is useless for compatibilization. 

Blends used to create MFCs can be separated into two broad categories those containing two condensation polymers that will cause a self-compatibilisation effect in the composite, and those requiring the addition of a compatibilizer if a chemical reaction between the constituent polymers is desired. For example, blends combining polyesters with polyamides fall into the former category while blends containing a polyolefin component belong to the latter. 

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