7.10 The measurement of bulk copolymerization of styrene (M1) and methyl methacrylate (M2) at 30°C in a feed of 0.031 mole fraction styrene with initiation by photosen- sitized decomposition of...

Extracted text: 7.10 The measurement of bulk copolymerization of styrene (M1) and methyl methacrylate (M2) at 30°C in a feed of 0.031 mole fraction styrene with initiation by photosen- sitized decomposition of benzoyl peroxide gave a value of 7.11x10-5 mol L- s-, while homopolymerization of styrene under the same conditions yielded a polymer- ization rate of 3.02x10-5 mol L-s- [H. W. Melville and L. Valentine, Proc. Roy. Soc., A, 200, 337, 358 (1952)]. Calculate the copolymerization rate from (a) chem- ical control model [Eq. (7.52)] and (b) combined model [Eqs. (7.46) and (7.56)] to compare with the experimental value. Use the homopolymerization rate constants at 30°C for styrene as k, = 46 L mol- s- and k, = 8.0x106 L mol- s- and for MMA as kp = 286 mol L- s- and k; = 2.44x10' mol L-s-. The reactivity ratios at 30°C arerį %3D 0.485 and r2 = 0.422. Make the comparison using o = 10 and o 13. Monomer density = 0.90 g/cm. Ans. Rate of copolymerizationx10°, mol Ls- Chemical control Combined model Experimental Eq. (7.52) Eqs. (7.46) and (7.56) ゆ= 10 ゆ= 10 $ = 13 $= 13 7.11 6.30 5.71 7.85 7.28