Process for polymerizing molecular-weight controlled polymer

A weight average molecular weight-adjustable polymer synthesis process, the polymer synthesis process comprising:

• a reactant feeding step of feeding a gaseous monomer, a surfactant, and an initiator into a reactor;
• a synthesis reaction step of conducting a synthesis reaction involving the monomer, the surfactant, and the initiator;
• and
• a product discharging step of discharging a polymer compound produced by the synthesis reaction,
• adjusting a weight average molecular weight of the polymer compound produced by the synthesis reaction by controlling a flow rate of the initiator, wherein the flow rate of the initiator fed is inversely proportional to the weight average molecular weight of the polymer compound,
• simultaneously and continuously performing the reactant feeding step, the synthesis reaction step, and the product discharging step after set-up of a reactor, and
• separating an unreacted portion of the monomer from the polymer compound by liquid-gas separation and feeding the unreacted portion of the monomer into the reactor.