Study On Hydrophobic Alkyd Resin /SiO₂ Organic-inorganic Hybrid Material

Basing on solution polymerization method,adipic acid and polyethylene glycol 400(PEG400)are used to synthesize alkyd resin in this paper.The effects of material ratio,reaction time,reaction temperature,heating mode and catalyst etc. on yield and molecular weight of alkyd resin are investigated.The optimized synthesis parameters for alkyd resin are as follow:molar ratio of adipic acid/PEG400 is 1:1.2,molar ratio of catalyst(Tin(â…¡)octanoate)/reactant is 8×10^-3, a non-linear heating mode from 140℃to 190℃is adopted.Basing on sol-gel method,tetraethoxysilane(TEOS),methylethoxysilane (MTES),alkyd resin are used to synthesize hydrophobic alkyd resin/SiO₂ organic inorganic hybrid material by two-step method.The Si-methyl groups of MTES contribute to hydrophobicity of the hybrid material.The contact angleθon the surface of hybrid material increases with the increase of the MTES wt%and keeps stable at about 126°for MTES wt%＞15.The transform infrared spectroscopy (FTIR)and X-ray photoelectron spectroscopy(XPS)spectra show that alkyd resin can hybridize with silica sol and form Si-O-C bonds.Moreover,the differential scanning calorimetry(DSC)results show that the heat resistant property of the hydrophobic alkyd resin /SiO₂ organic inorganic hybrid material has being improved with the increase of the SiO₂wt%Basing on solvent evaporation method,a compound emulsion agent is used to prepare alkyd resin/SiO₂ emulsion.The effects of the dosage and component of compound emulsion agent,stirring rate etc.on the properties of alkyd resin/SiO₂ emulsion are investigated.In compound emulsion agent,the anion emulsion agent is sodium dodecyl benzene sulfonate,while the non-ionic emulsion agent is composed of OP-10 and span-80(the weight ratio of OP-10/span-80 is 1:20).When the weight ratio of anion/non-ionic emulsion agent is 35/65 and the dosage of compound emulsion agent is 9wt%,the alkyd resin/SiO₂ emulsion is more stable. The emulsion particle size decreases with the increase of stirring rate and changes unobviously for stirring rate over 500r/m.