Studies On The Preparation And Properties Of 2-Hydroxy-3-Phenoxypropyl Starches And Its Dervivatives

2-Hydroxy-3-phenoxypropyl starches were synthesized by environmentally friendly process using phenyl glycidyl ether (PGE) as a hydrophobic reagent, water as a solvent and sodium hydroxide as a catalyst. The reaction conditions were investigated and optimized. Optimum conditions were obtained as follows:n(PGE):n(AGU)= 1.5, volume of solvent was V(H2O)=30mL,amount of NaOH was n(NaOH):n(AGU)=2.0, reaction time was 6 h, reaction temperature was 60℃,molar substitution (MS) of 2-hydroxy-3-phenoxypropyl was up to 0.84,the reaction efficiency(RE) was 56%.Under this conditions, different MS of 2-hydroxy-3-phenoxypropyl starches were prepared, the products were characterized by IR, 1H-NMR..When study the solubility properties of different degree of substitution of 2-hydroxy-3-phenoxy propyl starch ether (HPPSs) which have a good solubility with the degree of substitution MS= 0.05-0.32. The results of surface activity and emulsifying properties showed that the critical micelle concentration of HPPSs was varied from 1.54-0.24g/L with different degree of substitution of the hydrophobic group. The surface tension of the HPPSs was decreased with the increased of the degree of substitution of the hydrophobic group, when MS was 0.32, the lowest surface tension was 45.6mN/m. The emulsion stability of the HPPSs was increased with the increased of the concentration of the HPPSs. When the concentration was up to 4g/L to continue to increase on concentration will not significantly increase the stability of the emulsion. At the same time as the degree of substitution of the hydrophobic groups to increase, their emulsion stability also increased-2-Hydroxy-3-phenoxypropyl carboxymethyl Starches were synthesized by water insoluble 2-hydroxy-3-phenoxypropyl starches, water as solvent and sodium hydroxide as a catalyst, chloroacetic acid as a etherification agent. The results of surface activity and emulsifying properties showed that:the surface tension was gradually reduced as the hydrophilic groups and hydrophobic groups tend to balance, when the degree of substitution carboxymethyl MS =0.9, hydrophobic degree of substitution MS=0.84 the lowest surface tension is 43.2 m N/ m. At the same time, investigated the effect of pH value on the surface tension show that the best pH value was around 7.It can conclude that the better conditions for emulsification are pH= 7,hydrophobicity of the MS was about 0.7 to 0.9, carboxymethyl MS was about 0.6 to 0.8 at room temperature without salt conditions.