Reactivity Of Maleic Anhydride Research Articles

Real time assessment of the compatibilization of polypropylene/polyamide 6 blends during extrusion

The reactivity of maleic anhydride and acrylic acid polypropylene graft copolymers with amine groups and their effect in the compatibilization of polymer blends was analyzed in real time during the reactive processing of compatilized polypropylene/polyamide 6 (PP/PA6) blends. The presence of compatibilizers in the blend produces a block copolymer PP-PA6, which stays in the blends interface, lowering the interfacial tension and reducing the PA6 particle size, affecting the light extinction phenomena. The in-line optical detector is able to indirectly quantify the conversion of the compatibilization reaction of the blends. The signal intensity of the detector increases with the increase of the PA6 content due to the increase in the number of particles. Quantitative off-line FTIR analyses of the compatibilized blends have shown that the amount of block copolymer formed when polypropylene grafted with acrylic acid (PP-g-AA) is used as compatibilizer increases with its content in the blend. There is a good correlation between the in-line optical measurement and the off-line amidic bond content formed. Non-reacted compatibilizers are always present in the reactive blends whose content is proportional to its initial concentration. The PA6 particle size data obtained from scanning electron microscopy analysis showed good correlation with the in-line measurements. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers

Nucleophilic reactivity analysis: atom-bond electronegativity equalization method

The reactivity of maleic anhydride and β-propiolactone with respect to different nucleophiles is studied using atom-bond electronegativity equalization method. From our study, hardness and softness are found to be relative properties and that the Fukui function is not the only factor to determine the selectivity of a chemical reaction, while the hard and soft acid and base principle, in a local sense, can be used to understand this kind of reactivity.

The reactivity of maleic anhydride toward the 1-phenylethyl radical

The behaviour of the 1-phenylethyl radical as an initiating species was investigated using the end group method of Bevington et al. for a number of copolymerisations of methyl methacrylate with maleic anhydride and similar species. A strong selectivity for addition of the 1,2 disubstituted monomer was found in each case. The reactivity ratios obtained for addition of the 1-phenylethyl radical to styrene and maleic anhydride, when compared with published equivalents for the poly(styrene) radical, showed addition to the 1-phenylethyl radical to be more selective by a factor of approximately two. Similar results were found for each of the other species examined and it is suggested a penultimate effect of steric origin is responsible for the decreased selectivity of the poly(styrene) radical. No significant solvent effect was found on the reactivity of the 1-phenylethyl radical in the copolymerisation of methyl methacrylate and maleic anhydride.