Kinetics of Interfacial Reactions and Molecular Characterization

Low molecular weight reactants such as phthalic anhydride and dimethylsuccinic anhydride were used as model compounds for trimellitic anhydride terminated polystyrene and styrene-maleic anhydride (SMA) copolymer. As amine functional species, benzyl-amine and 1,2 diphenylethylamine, were employed, the transposal of the knowledge gained from model compounds to a real polymer blend system reacted in the melt under shear was only slightly instmctive. The low reactivity observed in the case of the reactive polymers has been ascribed to a chemically different environment and not to a diffusion-controlled process as is generally considered. 

The graft copolymer, in situ formed during reactive compatibilization, has to be isolated from the blend and well purified prior to characterization. Experiments of selective solvent extraction and hydrolysis always precede the spectroscopic characterization. It is fiequently a difficult task to efficiently isolate the species that bear the chemical grafts. 

The addition of solvent to the reacting components completely changed the reaction features. In Fig. 3.3 the extent of conversion of the EMA/PS-OH reaction in a blend is 

Schafer et al. [15] have also investigated the reaction kinetics of an oxazoline functionalized butadiene-co-acrylonitrile copolymer with a poly(ethylene-co-methacrylic acid). A two-layer specimen was used for the kinetics study. FTIR spectroscopy was carried out on the two-layer specimen annealed at different temperatures from 170 to 

230 °C for various time intervals. The formation of esteramide link is probed via the decrease of the oxazoline band (N = C) at 1664 cm and the appearance of the amide band (C = 0) at 1648cm . The FTIR spectra of the reacted systems at the indicated temperature and time conditions are given in Fig. 3.4. As shown in Fig. 3.5, the plot of the integration value as a function of the annealing time at the indicated temperature reveals clearly the effect of the reaction temperature on the reaction rate and conversion. As 

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