P(DADMAAC‐co‐DMAA): Synthesis, thermal stability, and kinetics

Abstract

The kinetics of copolymerization is one of the key factors for optimization the process in large scale of production. Copolymerization of N, N‐dimethyl‐N,N‐diallyammonium chloride (DMDAAC) with N,N‐dimethyl acrylamide (DMAA) was studied by a dilatometer technique using ammonium persulfate ([NH4]2S2O8) as an initiator. The effect of the parameters (including molar ratio of DMDAAC to DMAA, concentrations of monomers [M] and initiator [I], and the temperature) on the polymerization rate was analyzed. From these analyses it was found that the polymerization rate (Rp) with the above variables can be represented as the following relationship: Rp∝ [M]2.63; Rp∝ [I]0.40 andRp∝[MDMDAAC:MDMAA]‐0,86.The negative order found in the relationship of the reaction rate and the monomer composition indicated that the DMDAAC concentration in the monomers composition conversely affected the polymerization rate. The overall activation energy for the polymerization rate was 39.56 kJ/mol in the temperature range between 40°C and 60°C. Based on the experimental results, the mechanism of polymerization is discussed in detail. Different thermal properties for DMDAAC and DMDAAC‐DMAA were observed by differential scanning calorimetry (DSC), and thermogravimetry (TG) analysis. Addition of DMAA to DMDAAC lowered the thermal stability relative to the home polymer of DMDAAC.