Secondary polymers

The increased crosslinking may be attributed to the preferential generation of secondary polymer radicals due to the presence of excited MAH and therefore an increase in the amount of coupling of secondary polymer radicals rather than of pendant MAH radicals. 

Matting can be obtained by adding special mineral fillers, another secondary polymer that is miscible to a greater or lesser degree with the main polymer, or proprietary additives. 

Fig. 12.1.1 Dependence of order parameter, S. of the secondary polymer, spin-labeled poly (methyl methacrylate) (PMMA) and polystyrene (PST), bound to poly(maleic anhydride—styrene )-grafted silica on hexane content in ethyl acetate-hexane cosolvent. Numbers in parentheses are number average molecular weight of the secondary polymer. (From Ref. 48.)...

Depending on the fate of the secondary polymer radical produced, this could lead to either chain scission or cross-linking in the solid phase. 

The above discussion deals with the base polymer only. One can see that if the additive system imparts light scattering similar to these examples above, the effect on coloring the total resin system can be dramatic. We begin our discussion of additives by looking at polymer blends, where the secondary polymer can be considered an additive to the continuous base polymer. 

The crosslinking of EPR in the presence of radicals from peroxide decomposition (benzoylperoxide, dicumylperoxide etc.) by light or heat, is attributed to the attack on the secondary CH2 moieties and the generation of polymer radicals which couple either with similar secondary polymer radicals or polymer radicals generated by attack on the tertiary CH moieties on the propylene units in the chain. 

Hand, J.H. Williams, M.C. Effect of secondary polymer structure on the drag-reducing phenomenon. J. Appl. Polym. Sci. 1969, 13, 2499-2502. 

Sherborne et al. (1967) observed a 15% redaction in residnal oil satnration in a HPAM flood. Wreath (1989) did not observe rednction in residnal oil satnration in tertiary polymer flooding in Berea and Antolini sandstones. Wreath (1989) did not observe rednction in residnal oil satnration in one Berea core even in secondary polymer flood mode, bnt did observe rednction in one Antolini core that was a heterogeneons and eolian sandstone. For more discnssion about kj curves in polymer flooding, see Section 5.4.5. 

Ushakova, V.N. Kuleznev, Modification of the properties of secondary polymers. Moscow (2002) (in Russian). 

Asserud et al. [70] used SEC with an electrospray interface to couple to a FTMS. They characterized a variety of poly (methyl methacrylate) polymers. This allowed them to accurately determine not only the molecular weight distribution, but also the end-group functionality and observe secondary polymer distributions... 

Dispersibility of Composite 2 in Cosolvent. 230 ESR Study of Spin-Labeled Secondary Polymer 231... 

Preparation of ultrafine monodisperse hybride particles, dispersible in low polar organic solvent, from monodisperse colloidal silica by two-step polymer modification was studied. Bindings of the secondary polymer to monodisperse poly(maleic anhydride-styrene)-modified colloidal silica particles (120 nm) have made the composites in low polar solvent dispersible. The dispersion of the particles in good solvent for the secondary polymer is due to the steric repulsion of solvated polymer chains. The dispersibility of the hybrid particles in poor solvent-rich solution was controlled by delicate balance between nonpolar-nonpolar interaction and electrostatic repusion among the particles. 

The reactions of composite 1 with secondary polymer of amino-terminated poly(methyl acrylate), poly(methyl methacrylate) or polystyrene were carried out in acetone or tetrahydrofuran under refluxing for 24 h. The amount of the binding polymer decreased with increasing of the molecular weight, as shown in Table 17.1. 

Therefore, dispersion-aggregation behavior of the composite 2 in poor solvent-rich solution was probably controlled by delicate balance between the electrostatic repulsion due to negatively high -potential and nonpolar-nonpolar interaction of shrunk secondary polymer chains in interparticles. 

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