step growth polymerization

[syarif]

Oh my friends, I can't solve the polymerization reaction in polycondensation reactor.. I have difficulty to understand the mechanical and chemical reaction in polycondensation reaction especially in step growth polymerization for producing polyethylene terephtalate from PTA and EG, How the monomer become polymer in melted state and polymer become polymer with hight intrinsic viscosity in solid state polycondensation so degree of polymerization can achieved required molecular weight of PET bottle grade, How the reaction happen?? Huh.. I'm very confuse because there are different references explain the mechanism and kinetical of its reaction and non of them explain it clearly. I hope can solve immediately..anyone can help me? thank u very much.