The synthesis, modification and characterization of nano-sized emulsion polymers using functional vinyl monomers

In the first part of this work; the structure of oligomeric N-methylol acrylamide (o-NMA) having two different functionalitiy, reactive functional end groups and unsaturation, was determined. It was designed to be used as a reactive surfactant in vinyl acetate (VAc) based copolymers. At a later stage, preliminary studies were done for the determination of process type, components, quantities and the other conditions of emulsion polymerization of VAc with two maleic acid diester, dibutyl maleate (DBM) and dioctyl maleate (DOM). Using information from these studies, a copolimerization procedure that thought the most efficient polymerization would be carried out and would be used at the other studies was developed. Formed the basis for this recipe, the copolymerizations were composed of five different series. In these series comonomer type and ratio, the amount of emulsifier and the changes of amounts of initiator and reactive surfactant, o-NMA, in the reactor and nutrition were examined. A large number of characterization methods were applied for the revealing the impact on resulting copolymer latexes and their films.In the first series, without changing the total amount of thermal initiator potassium persulfate (K2S2O8) five different copolymerizations were performed in the semi-batch emulsion polymerization of VAc/DOM monomer pair. In these polymerizations the amount of VAc/DOM used in the reactor initially (in nucleation process) were changed between 10-50% by weight. As a result of characterization of copoymer latexes and their films, the most stable latex was obtained the rate of 50% and a later series of experiments were based on this rate.In the second series, without changing the total amount of functional, reactive surfactant, o-NMA, that used in the semi-batch emulsion polymerization of VAc/DOM monomer pair, five different copolymerizations were performed. In these copolymerizations the amount of VAc/DOM used in the reactor initially (in nucleation process) were changed between 0-100 % by weight. The characterizations of both latexes and films showed that participitation of o-NMA in copolymerization is the highest when it is not in the reactor in other words all of it is in the feeding. The stability of copolymer latexes would be reduced if the ratio of this compound in the reactor got over 50%. It was concluded that this situtain caused by the tendency to homopolymerization of reactive compound in the water phase. The later series of experiments it was decided to use the rate 50 % by weight of o-NMA in the reactor initially.In the third series, five different copolymers that contained various amount of emulsifier were synthesized. In these copolymerizations, type, composition and ratio in the reactor of non-ionic emulsifier system of 10-ethoxylated nonylphenol and 30-ethoxylated nonylphenol (NP 10 and NP 30) were determined as a result of preliminary experiments. When the latex and film properties of copolymers were analyzed, it was concluded a limit emulsifier ratio should be considreded for the VAc/DOM semi-batch system.In the last two series, using the DOM and DBM comonomers and changing the ratio of these comonomers in monomer mixture nine polymerizations were performed with these two different monomer pairs, VAc/DOM and VAc/DBM. The effects of these two comonomers on emulsion polymer of VAc were compared. It was seeen that the changes in the ratio of comonomers in monomer mixture were created significant differences on physical, physicochemical and film properties of copolymers. When the amount of these two comonomers came up a certain rate the main characteristics of comonomers such as latex stability, minimum film forming temperature (MFFT), glass transition temperatrure (Tg) and resistance to water had provided a significant advantage against the homopolymer of VAc.