Abstract: A process for polymerization of vinyl chloride may include contacting vinyl chloride, demineralized water, at least one stabilizer agent, at least one dispersing agent, an initiator and optionally one or more comonomers; continuously feeding the vinyl chloride, demineralized water, at least one stabilizer agent, at least one dispersing agent, an initiator and optionally one or more comonomers into a tubular reactor having a length of at least 20 times an internal diameter of the tubular reactor; and continuously polymerizing the vinyl chloride, and optionally the one or more comonomers.

Abstract: A process for propylene preliminary polymerization in liquid phase that occurs in a continuous preliminary polymerization reactor may include feeding a propylene monomer and a Ziegler-Natta catalyst system having (a) a pro-catalyst having an internal electron donor comprising a substituted phenylene aromatic diester, (b) a catalyst activator and optionally (c) an external donor, into the continuous preliminary polymerization reactor, wherein the feeding is carried out without pre-contact of the pro-catalyst with the catalyst activator, and also without pre-contact of the catalyst activator with the propylene monomer before entering the continuous preliminary polymerization reactor.