Research On The Preparation Of PDMC With High And Serial Molecular Weight

Methacrylatoethyltrimethyl ammonium chloride (DMC) is one of the commonly used cationic monomer, its copolymer studied more but its homopolymer remains to be studied. In this paper, a new preparation method for poly(methacrylatoethyltrimethyl ammonium chloride) (PDMC) is optimized to obtain PDMC with high molecular weight, while a controlled polymerization method of PDMC with high monomer conversion and serial molecular weight is reasearched. Further, the realationship between structure and thermal properties of serial molecular weight PDMC is researched.Firstly, using industrial monomer solution of methacrylatoethyltrimethyl ammonium chloride(DMC) as the raw material, peroxide(A) as the initiator and tetrasodium EDTA(Na4EDTA) as the chelating agent, the preparation method was researched with the method of adding initiator all at once, two-step increasing of temperature for aqueous polymerization. The influencing factors such as w(DMC), m(Na4EDTA):m(DMC), m(A):,(DMC) and the temperature of initiation T1 on the intrinsic viscosity of PDMC were investigated via the orthogonal experimental method. The results showed that the functional strength order of the factors was w(DMC)>m(Na4EDTA):m(DMC)>T1>m(A):m(DMC), and the optimal process condition were w(DMC)=72.5%, m(A):m(DMC)=0.20%, m(Na4EDTA):m(DMC)=0.18%, and polymerization carried out at 40℃ and then 55℃, each for 3 h. The intrinsic viscosity of PDMC product and monomer conversion under optimal process conditions reached 10.38 dL/g and 98.40% respectively. The intrinsic viscosity of PDMC product exceeds the maximum value which has been reported in the literature. Structure of the product was characterized via FTTR and 1HNMR and the Mn was measured with GPC-MALLS.Then, without any transferring and inhibiting agents added, the series of PDMC with intrinsic viscosities range from 2.00 to 10.00 dL/g and monomer conversion more than 98.00% could be obtained by only controlling initial amount of monomer DMC combined with A amount added. This method has not yet been reported in the literature, while establishing a controllable preparation for the PDMC products with serial molecular weight. Structure of the series product were characterized via FTIR and 1HNMR and the Mn were measured with GPC-MALLS.Finally, thermal decomposition were determined by TG-DSC. The realationship between structure and thermal properties of serial molecular weight PDMC was obtained. The PDMC products with serial molecular weight and the realationship between structure and thermal properties were the foundation to the structure, properties and its application.