Interfacial Modification of Heterogeneous Materials Based on Polypropylene

4 INTERFACIAL MODIFICATION OF HETEROGENEOUS MATERIALS BASED ON POLYPROPYLENE 

It is well accepted that the good properties of the isotactic polypropylene as an engineering polymer matrix in thermoplastic composite materials and engineering blends are seriously affected by the inability of this polymer to develop an adequate level of interfacial interaction with polar components such as mineral fillers (calcium carbonate) and reinforcements (talc, mica, wollastonite), synthetic reinforcements (glass fibers, carbon fibers, and nanotubes), or engineering polymers such as polyamide, aliphatic polyesters, and so on. 

In order to preserve the affinity with the nonpolar polypropylene matrix, the substitution of a small fraction of the matrix by another polypropylene with just a few polar groups grafted onto its backbone has been proven, in the last 20 years, to be a very effective strategy to promote isotactic polypropylene for engineering polymer applications. 

Among the different polar groups chosen to be grafted into polypropylene, maleic anhydride has proven to be of the highest efficiency as follows from the 

From the point of view of designing at the interface level, there is not yet available any mathematical model based on the physicochemistry of this spatial region for general application to develop any composite material based on organic matrices like polypropylene. 

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