Study On Synthesis And Property Of Water-soluble Polyelectrolyte

AbstractPoly(allylamine hydrochloride) (PAH), poly(acrylic acid) (PAA), polyacrylamide (PAM) and polyethylene amine (PVAm) are water-soluble polyelectrolyte. There are great significance in the polymerization preparation and modification as well as practical applications, because of the reactive amino, carboxyl and amide groups in polymer molecular chains, respectively.The main contents of the thesis are as follow:(1) PAH was synthesized by solution polymerization with allylamine hydrochloride (AH) as monomer, ammonium persulfate(APS)/sodium bisulfite as redox initiators, respectively. The chemical structure and properties of PAH were studied through Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance (NMR) and thermogravimetric analyzer (TGA). Meanwhile, the effects of reaction temperature, initiator concentration and monomer concentration on polymerization conversions and relative viscosity of PAH was also studied. The results showed that PAH was prepared because the 998cm-1 C=C double bond characteristic peak was disappeared in IR spectra, and the polymer was very different from monomer with peak profile, peak areas and chemical shift in 1H-NMR spectra. The PAH had two-decomposing stages. It was decomposed completely at 700℃, which showed good thermal stability. The conversion of monomer increased and the relative viscosity of PAH decreased with the increasing of initiator concentration. Both the conversion of monomer and the relative viscosity of PAH increased with the increasing of monomer concentration.(2) PAA was synthesized by aqueous solution polymerization with acrylic acid (AA) as monomer, APS as initiators, respectively. The structure of PAA was characterized by FTIR, at the same time, the effects of reaction temperature, initiator and monomer concentration on solid content and viscosity-average molecular weight (Mη) of PAA were studied. The intrinsic viscosity of PAA solution was analyzed in the different pH conditions. The results showed that PAA was prepared because the 1600-1650cm-1 C=C double bond stretching vibration characteristic peaks was disappeared in IR spectrum. PAA solid content and Mη increased with the increasing of monomer concentration. PAA solid content increased and Mηdecreased with the increasing of initiator concentration. The intrinsic viscosity of PAA solution increased at first then decreased with the increasing of pH value of solution, and there was the maximum of intrinsic viscosity when pH value was about 8. PAA solid content was higher (13%) and the Mηwas up to 1 million when the experimental conditions was that the initiator concentration was 0.3%, monomer concentration was 13%, the pH value was 6.0, the polymerization temperature was 70℃and the reaction time was 2 h, respectively.(3) PAM was prepared by aqueous solution polymerization with acrylamide (AM) as monomer and APS/sodium bisulfite as redox initiators, respectively. Furthermore, PVAm and polyvinylamine hydrochlorid (PVAm·HCl) was prepared through Hofmann degradation of PAM. The chemical structures and properties of the polymers were studied through FTIR and TGA. Meanwhile, the effects of reaction temperature, monomer concentration, initiator concentration and pH value on conversion of monomer and Mηof PAM were studied. The 998cm-1 characteristic peak was disappeared in FTIR spectrum, which meant that the double bond was fractured and PAM was prepared. The 1670cm-1 C=O absorption peak was disappeared in FTIR spectrum showed that PVAm was prepared. Results of TGA showed that the thermal stability of PVAm is lower than that of PAM.. It was found that Mηof PAM decreased with the decreasing of initiators concentration and the increasing of monomer concentration. The conversion of monomer increased with the increasing of reaction temperature, and Mηof PAM decreased in the overall trend. The conversion of monomer increased at first then decreased with the increasing of pH value, and the maximum conversion of monomer was appeared when pH value was 7.0. The Mηof PAM was from 200000 to 300000 when the experimental conditions was that the initiator concentration was 0.4%, monomer concentration was 10%, the pH was 7.0 and the polymerization temperature was 50℃, respectively.