Functionalization of polyolefins by reactive processing

Abstract

From the study of the modi cation of PE and PP with maleic anhydride, maleic acid and an acid salt of maleic acid (sodium maleate) in a liquid or solid state, it was shown that the main controlling factor in the solid state modi cation of polyole ns is the joint plastic deformation of the system components. The changes of molecular characteristics were investigated by gel permeation chromatography. It was shown, that the molecular weight of modi ed PP samples increases at times by linking with intermolecular associates in the solutions. The formation of associates plays essential role in the behaviour of solutions of modi ed PP. The morphology of modi ed PP samples was investigated by scanning electron microscopy. It was shown, that intermolecular association strongly in®uences on the processes of formation and growth of nucleus and the structure of generated polymeric materials.

Preparation and Characterization of Extruded Composites Based on Polypropylene and Chitosan Compatibilized with Polypropylene-Graft-Maleic Anhydride

“…Additionally, its hydrophilic character does not allow its homogeneous dispersion in the PP matrix that is hydrophobic; however, the addition of compatibilizer improved the homogeneity of the films, as shown in Figure 3(2A–2C). This behavior is consistent with the literature where it was reported that the use of polymers grafted with maleic anhydride are good compatibilizers for immiscible binary mixtures [13,14,15,16]. Moreover, films with smaller chitosan particle size (Figure 3(3A–3C)) showed better dispersion of the particles of chitosan in the PP matrix, so in these films the formation of agglomerates is almost unnoticeable, which is attributed to the good dispersion of the chitosan particles in the PP matrix.…”

Reactive melt modification of polyethylene by ethyl acrylate/acrylic acid copolymers: rheology, morphology and thermal behavior

“…Peroxide-initiated free radical polymerization is probably the simplest, oldest and most widely used method for the synthesis of graft copolymers which is also adaptable to a variety of commercial applications [10]. The blends of polyolefins and polyacrylates are of clear technological interest [11].…”

Degradability of extruded polyethylene/chitosan blends compatibilized with polyethylene‐graft‐maleic anhydride under natural weathering

“…The resulting blend of these two types of polymers is generally immiscible. Polymers grafted with maleic anhydride are used as compatibilizers for immiscible binary mixtures, showing good results …”