Study On Synthesis And Properties Of Novel Borate Ester Surfmer And Its Polymers

Borate ester surfactants is a kind of special surfactants with excellent surface activity,which possess much characteristic features compared with ordinary surfactants, e.g.antistatic, antiwear, flame retardancy, etc.. In the paper, novel non-ionic borate surfmerBES and its homopolymer PBES, BES/acriamide copolymer P(BES-AM) were developed.The effects of several factors on synthesis/polymerization were investigated, andoptimized synthesis techniques were obtained. The structures of synthesized productswere characterized by FT-IR,¹H-NMR,GPC and intrinsic viscosity measurement. Usingsurface tension and TEM method, their surface physical-chemistry properties, e.g. surfaceactivity, mixed solution effects., were studied, and their applications in aqueous system,such as the metal corrosion inhibition and dispersion property in the preparation of solublenano-Ni catalyst.The results showed BES has strong antihydrolysis ability and homo- and co-polymerization properties, with excellent surface activity. At 25℃, pH=7, critical micelleconcentration(cmc) is 0.066 mmol·L^-1,γ_cmc is 29.2 mN·m^-1, that is better than severaltypes of ordinary surfactants with the same hydrocarbon chain. The relative moleculeweight range of PBES products is approximately 1.5×10⁴～3.5×10⁴, with cmc 0.066mmol·L^-1,γ_cmc 29.2 mN·m^-1, which is similar to surface activity of ordinary low-molecule-weight surfactants. The mixed solutions of BES/PBES with sodiumdodecylbenzene sulfonate have obviously strong synergistic interactions. The presence ofPBES results in the emerge of two transition points C₁ and C₂ along the surfacetension-concentration curve of LAS aqueous solution, C₁＜C₂＜cmc_LAS. The intrinsicviscosity of copolymer borate P(BES-AM) is the range of 47～88 mL·g^-1(calculated relativemolecule weight is 9.8×10⁴～2.2×10⁵), andγ_cmc iS 30.5～40.5 mN·m^-1, cmc is 0.23～2.30g·L^-1, which is also close to the surface activity of ordinary low-molecule -weightsurfactants.PBES molecules can spontaneously self-assembly to form vesicles in aqueoussolution. PBES vesicles have the shape of circle or ellipse, a diameter of 150～250 nm at0.1 mol·L^-1 NaCl aqueous solution, and have strong stability at the mixed aqueous solutionof alcohol-NaCl. Adopting packing parameter theory, the formation mechanism ofself-assemble structures of BES and PBES molecules at solution based on the approximateprocess for PBES molecules was investigated, and the model of their structures was given. BES and PBES, P(BES-AM) have good metal corrosion inhibition property superiorto regular inhibitor OP-10, Tween-85. The inhibition effect of PBES on the corrosion of45# carbon steel in 1 mol·L^-1 HCl solution is the best at 30℃and 50℃, with inhibitionefficiency up to 97%. The second is BES. The inhibition efficiency of P(BES—AM) mayalso exceed 87%. Using several surfaetants as dispersion agent, soluble nano-Ni catalystswere prepared for the synthesis of chloroaniline through catalytic hydrogenation ofehloronitrobenzene. Based on recycled catalysts, the conversion of synthesis reaction reachthe highest 90.2% by using PBES compared with other surfactants.