The Study Of Acrylamide/Acrylic Acid Controlled Polymerization

Atom transfer radical polymerization （ATRP）, was developed in1995, a newpolymerization. By ATRP technique, it can be obtained very narrow molecular weightdistribution of polymers; can control the polymer molecular weight; can be easily prepared byblock, star, graft, etc.,which has a strong structure of copolymers. So in controlled radicalpolymerization, ATRP research is very active. In recent years, it has becomed the studyingfocus of many scholars. Reverse atom transfer radical polymerization （RATRP） is derived onthe basis of the ATRP, it has overcome the shortcomings of the conventional ATRP initiatorhas toxic, catalytic metal ions can not be keep, these have become an important aspect of thestudy of RATRP. Water-soluble monomer RATRP research is one aspect of the presentstudy;in addition, using of green solvents-water as a reaction medium is also an effectiveway to achieve RATRP.In this paper, using the RATRP, in homogeneous aqueous media using Cu （Ⅱ）, Fe （Ⅲ）two kinds of catalysts as the catalytic systems, water-soluble initiator to lead the acrylamide-acrylic acid controlled copolymerization. The main contens of the paper are:1、In the aqueous phase, using potassium sulfate （KPS） as initiator, the complex of copperchloride （CuCl₂） and ethylenediamine （en） to formed as a catalys to carry out the acrylamide（AM）-acrylic acid （AA） controlled radical polymerization. Inspect the raw materials ratio,polymerization temperature, reaction time and other conditions; let the reaction showed acertain degree of controllability. The controllability of acrylamide-acrylic acidcopolymerization discussed by measuring the monomer conversion rate, ln（[C]0/[C]） withtime that the linear correlation coefficient R². Through the infrared spectra to verify thestructure of the polymer, and proved the polymer is the acrylamide-acrylic acid copolymer.When the materials ratio are: n（AM/AA）: n（CuCl₂）: n（en）: n（KPS）=400:0.75:1.5:0.25,temperature is45℃, the mass fraction of the monomer is10%, reaction time is7h, the linearcorrelation coefficient is0.99271, linear relationship is good, under this condition the reactionsystem controllability performance is good.2、 In the aqueous phase, using potassium sulfate （KPS） as initiator, the mixture of o-phenanthroline （phen）/ethylenediaminetetraacetic acid （EDTA） complexes with ferricchloride （FeCl₃） as the ligand to carry out the acrylamide （AM）-acrylic acid （AA） controlledradical polymerization. Inspect the raw materials ratio, polymerization temperature, reactiontime and other conditions; let the reaction showed a certain degree of controllability. Thecontrollability of acrylamide-acrylic acid copolymerization discussed by measuring themonomer conversion rate, ln（[C]0/[C]） with time that the linear correlation coefficient R².Through the infrared spectra to verify the structure of the polymer, and proved the polymer isthe acrylamide-acrylic acid copolymer. When the materials ratio are: n（AM/AA）:n（complex）: n（KPS）=800:0.5:0.9, the reaction temperature is50℃, the mass fraction of themonomer is10%, reaction time is8h, system dynamics linear curve is better，the linearcorrelation coefficient is0.99336, molecular weight of the polymer increases themonomer conversion with linearly, controlled polymerization is achieved.