Statistical Multipolymers

To supplement the kinetic data in Fig. 3.1.3, Tables 4.1.1 and 4.1.2, wt%AA data are shown below using H-NMR methods with pyridine-d5 as solvent. Copolymer spectfa were obtained using a Varian-400 MHz spectrometer. Solid copolymer samples were dissolved in a 5 mm NMR test tube with a concentration of 0.1 g/ml. The H-NMR was performed at 50°C and the measurement parameters were as follows acquisition time of 2.502 s, spectral width of 5,000 Hz, pulse width of 4.5 s, and number of scans equal to 16. The C-NMR analysis was done at room temperature using the following acquisition parameters acquisition time of0.640 s, spectral width of 25,000 Hz, pulse width of 4.5 s, and number of scans between 2,000 and 8,000. 

Proton and C-NMR plots for pyridine and a typical S/AA copolymer are shown inFigs.4.1.6. 1.8. 

All the GPC results in Tables 4.1.1 and 4.1.2 show unimodal peaks. This could indicate relative absence of random S/AA copolymer species. Also, molecular weights from the RI detector measurements are consistently larger than those from UV detector measurements. This indicates the disproportionate presence of AA in 

For the products in Fig. 3.1.3, solubilities in toluene as well as % solids in emulsion were obtained. Emulsification was generally done by dissolving the product in THF and then adding ammonia-water. Finally, the THF was stripped off with heat combined with addition of makeup water. 

It is evident that the FRRPP products (using DEE as solvent) were mostly soluble in toluene. Equivalent solution products seemed to be less soluble in toluene. This indicates the formation of significant random copolymer and/or homopolymers. As far as emulsifying capability is concerned, the higher the AA content of the FRRPP product, the more emulsifiable it is in water. Finally, it is worth noting the potential of products made from cyclohexane (see Tables 4.1.1-4.1.2), due to relatively high molecular weight products with relatively narrow MWDs. However, based on Table 4.1.3, these cyclohexane-based mns form less amphiphihc materials compared to those from the ether-based runs (Caneba et al., 2(X)3). 

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Poly(vinyl acetate)-Based Statistical Multipolymers... 

In this chapter, implications of the FRRPP phenomenon are presented in terms of unique polymerization production system systems. Control over the rate of polymerization has been exploited, resulting in the formation of new types of statistical and block multipolymers. 

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