Continuous polymerization -> inline devolatilization -> melt transfer

A continuous free-radical CSTR makes polystyrene-like polymer at 10% conversion per pass, on published styrene/AIBN rate constants (kp 0.60 m3/mol/s at 350 K, kt 1e5 m3/mol/s, AIBN kd 9e-5 1/s; Polymer Handbook order of magnitude), which give a kinetic chain length of 259: Mn 26.9 kg/mol, Mw 53.8 kg/mol, PDI 2. The effluent flashes at 500 K and 1 atm on the real Flory-Huggins activity of the solvent, stripping 99.9% of the residual monomer for recycle and leaving a melt carrying 0.24 wt% of it. The melt then flows through a 20 m, 100 mm transfer line whose pressure drop uses a non-Newtonian melt viscosity: the reactor's own Mw, carried with the polymer through the flash and into the pipe, sets the zero-shear viscosity by the 3.4-power law (800 Pa s at 25 kg/mol, so about 10,800 Pa s here) and Carreau shear-thinning brings it to about 6,300 Pa s at the wall shear rate. The polymer is counted per chain (polymer_basis 'chain'), the basis the Flory-Huggins package reads: its molar volume is Mn over a 1040 kg/m3 melt density. Honesty notes: 'ethanol' stands in for the monomer as the Flory-Huggins solvent (its volatility, not styrene's) with monomer_mw overridden to styrene's 104 g/mol; the melt density, the viscosity reference point and the Carreau constants are typical polystyrene values, not a fit to a grade; the flash is isothermal (its duty is reported, not designed against a heater).