Research On The Preparation Process Of PDMDAAC With Low Residual Monomers And Narrow Distribution

In this paper,the preparation process of PDMDAAC with low residual monomers and narrow distribution was researched by using industrial dimethyldiallylammonium chloride (DMDAAC) as a raw material, ammonium persulfate(APS) as an initiator and aqueous solution polymerization as a synthetic method.On the base of literature methods and the principles of polymerization, the feed methods of initiator were researched by using molecular weight distribution and monomer conversion as assessment indicators. Based on the optimum feed method of initiator, the process factors of polymerization such as amount of initiator, initial concentration of monomer, initiating and maturation temperature, amount of Na4EDTA and reaction time were researched, and the optimum process conditions were obtained by using monomer conversion as the primary assessment indicator, intrinsic viscosity and molecular weight distribution as the secondary assessment indicators.The PDMDAAC product with intrinsic viscosity1.03dL/g, monomer conversion99.96%and molecular weight distribution1.87was obtained. The corresponding optimum process conditions as follows:m(APS):m(DMDAAC)=3.0%, w(DMDAAC)=60%, T1=50, T2=75℃, m(Na4EDTA):m(DMDAAC)=0.0142%,t=7h.And the PDMDAAC product with intrinsic viscosity0.58dL/g, monomer conversion99.95%,molecular weight distribution1.66was obtained.The corresponding optimum process conditions as follows:m(APS):m(DMDAAC)=4.0%, w(DMDAAC)=55%,T1=50, T2=75℃, m(Na4EDTA):m(DMDAAC)=0.0071%,r=8h.Furthermore, on the base of the optimum process conditions, the effect of process factors on the intrinsic viscosity, monomer conversion and molecular weight distribution of polymer products were studied.The above research results of preparing PDMDAAC with low residual monomers and narrow distribution have offered an experimental foundation for PDMDAAC with a series of intrinsic viscosities, low residual monomers and narrow distribution.