Kinetic parameters, polyamides

Effects of maleated ethylene-propylene diene rubber (EPDM) on the thermal stability of pure polyamides, and polyamide/EPDM and polyamide/poly (ethylene terephthalate) blends kinetic parameters and reaction mechanism/Zl. Vieira, V.L. Severgnini, D.J. Maasra MS. Soldi, E.A Pinheiro, AT.N. Pires and V. ScAAilPolymer degradation and stability (2001), 74 1 151-157. 

Detailed kinetic schemes have also been proposed for many other polymers and the work of Bockhom et al.6-8 is representative of this large area of the literature for schemes relating to polyamide 6, PP, PE, and other polymers. Other experimental approaches, mainly aimed at identifying Arrhenius parameters in similar schemes, are discussed by Howell,9 Lehrle et al.,10 Shyichuk,11 Wilkie,12 and Holland and Hay.1314... 

Second-order rate constants for some acid-catalyzed polyesterifications and polyamidations obtained by the above method are shown in Table 5.3. The Arrhenius parameters A and E of the equation k = Aqxp —E/RT) are also tabulated for those reactions that have been studied kinetically at more than one temperature. 

Polyamides clearly dominate the field of thin-film composites by interfacial polymerization. The composition and morphology of the membranes depend on different parameters, including the concentration of the reactants, their partition coefficients and reactivities, the kinetics and diffusion rates of the reactants, the presence of by-products, competitive side-reactions, cross-linking reactions and postreaction treatment... 

Analysis of the kinetics of the recovery process in terms of r ,ax, To (see Fig. 13.2) provides a further means to quantitatively assess phase behavior (Ellis 1990 Hong et al. 1998). The structural dependence of these parameters has made it possible to investigate the phase behavior of blends containing aromatic polyamides (Ellis 1990). Despite the similarity in structure of the blend components and therefore the close proximity of the glass transition temperatures, Ellis was able to confirm the immiscibUity behavior predicted using the mean field binary interaction model (ten Brinke et al. 1983 Paul and Barlow 1984). 

Several parameters have to be taken into account in order to explain the differences in reactivity observed when using various polyamide and polyether blocks. Considering the nature of the polyether block, the nature of the functional end-group is one of the major factors influencing the polyesterification kinetics. 

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