Butadiene-maleic acid copolymers, properties

Mixtures of PPE and PS, or styrene-butadiene-styrene block copolymers have been extruded with maleic anhydride of fumaric acid to obtain compatibi-lized blends [42], In the same way, PPE with pendant glycidyl groups can be co-extruded with a poly(olefin) having anhydride groups [28], PPE can be grafted onto poly(ethylene) by melt kneading both modified polymers in the presence of a binder such as phenylenedi-amine. Both polymers are modified with maleic anhydride. The grafting takes place in situ. Amines may enhance the improvement of certain physical properties when used in combination with various compati-bilizers [29]. 

Additionally to the procedures described earlier, improvements for thermostabilization is copolymerisation of vinyl chloride with suitable monomers. A great number of monomers were investigated to optimize the properties of resins. But only vinyl acetate, vinylidene chloride, ethylene, propylene, acrylonitrile, acrylic acid esters, and maleic acid esters, respectively, are of interest commercially [305,436,437]. The copolymerization was carried out in emulsion, suspension, and solution in connection with water- or oil-soluble initiators, as mentioned elsewhere. Another possibility for modifying PVC is grafting of VC on suitable polymers [305,438], blends of PVC with butadiene/styrene and butadiene/ methacryl acid esters copolymers [433], and polymer-analogous reactions on the macromolecule [439,440] (e.g., chlorination of PVC). 

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