Process Optimization Studies for Synthesis and Applications of P(DADMAC) Cationic Homopolymer for Enriched Hair Care Formulation

Abstract In the present research work, the free radical solution polymerization technique was established to synthesize the stable P(DADMAC) [poly(diallyl dimethyl ammonium chloride)] cationic homopolymer in an aqueous medium. The polymerization of DADMAC monomer was accomplished through initiation by using water‐soluble initiators such as ammonium persulfate (APS) and potassium persulfate (KPS) and propagation through two vinyl double bonds at 70–75 °C for the reaction period of 5 h. The effect of initiator concentration and reaction temperature on the conversion of DADMAC to P(DADMAC) homopolymer was optimized based on the elucidation of structural properties and evaluation of the average molecular weight and viscosity of the product. The chemical structure of the P(DADMAC) was examined using Fourier transform infrared spectroscopy (FT‐IR) and subsequently verified through proton nuclear magnetic resonance spectroscopy ( 1 H‐NMR). The gel permeation chromatography (GPC) technique was employed to estimate the average molecular weight of the P(DADMAC) cationic homopolymer. The surface active properties of the P(DADMAC) homopolymer were analyzed by using a surface tensiometer at 1–1000 mg/L at 25 °C, which demonstrated the reduction of surface tension of water from 72 to (40.4 to 47.6) mN/m compared to (DMAPMA ‐co‐ C 12 DM) and (DMAPMA ‐co‐ C 10 MVBA) polymers that are reported in the literature. The hair care properties of P(DADMAC) were examined through the formulation of conditioning shampoo, the evaluation of surface activity, and the physicochemical and rheological characteristics of the formulation.