Molecular weight vs. conversion

Figure 6. Molecular weight vs. conversion for poly(methyl methacrylate)...

Rate constant for initial weight loss /J dMA M, df j,=0 Molecular weight against time Molecular weight vs. conversion Introduction of chain transfer... 

Fig, IA. Number of polymer chains vs conversion. B Number average molecular weight vs conversion. C Rate of polymerization vs time. D Conversion vs time. Diagnostic plots for instantaneous initiation (At), with various chain transfers (A2a, A2b, A2c) and for slow initiations (A3a, A3b)... 

Figure 2,5 Molecular weight vs conversion plot for Grignard metathesis polymerization of 2-bromo-5-chloromagneslum-3-dodecylthiophene initiated by nickel terminated poly(3-hexylthiophene) [Mht]q = 0.02 mol [Ni(ll)]o = 0.6 x 10 mol [MotJo = 0.04 mol L THF 18-20°C. Reprinted with permission from M. C. lovu, E. E. Sheina, R. R. Gil and R. D. McCullough. Experimental evidence for the quasi- living nature of the Grignard metathesis method for the synthesis of regioregular poly(3-alkylthiophenes). Macromolecules 38(21), 8649-8656 (2005). Copyright 2005 American Chemical Society...

Figure 2.7 Molecular weight vs conversion plots for nickel- and palladium-mediated GRIM polymerization of 2,5-dibromo-3-hexylthiophene). Nickel-mediated GRIM [M]o = 0.1 mol THF [Ni o= 15 x 10 mol L 23°C. Palladium-mediated GRIM [M]o = 0.1 mol [Pd]o = 1.5 x 10 mol 45°C...

Deviations in the emulsion polymerization of VC from the expected behavior were discussed by Chedron [104] in terms of the aqueous polymerization and its competition with the micellar polymerization. The monomer-saturated aqueous phase and precipitation of growing radicals should support the importance of the aqueous-phase polymerization. The molecular weights of poly(vinyl chloride) slightly decreased with emulsifier concentration and increase with conversion. The trend of the molecular weights vs conversion dependence was similar to that in Ref. [102]. 

Molecular weight vs. conversion curves as followed by GPC vfc. polystyrene standards indicate that relatively high molecular weights are obtained at tow conversions (Mn 20,000 for the polymerization of 2fi 4000 for 3500 for 2bX This supports a chain growth mechanism. Figure 3 shows a comparison of the Mw vs. time curve for 2a coiq>ared to the expected molecular weights calculated for a step growdi process. 

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