有机硅改性聚氨酯微球的合成及性能研究

Synthesis and characterization of PU microspheres modified by organic silicon

以甲苯二异氰酸酯(TDI)、聚己内酯二元醇(PCL)、端羟基聚二甲基硅氧烷(DHPDMS)和二羟甲基丙酸(DMPA)为主要原料,通过自乳化的方法合成DHPDMS改性聚氨酯微球。考察了n(NCO)/n(OH)、DHPDMS的质量分数、DHPDMS的分子量、乳化时间和CaCl2浓度对改性聚氨酯溶液外观、黏度(η)、溶胀率(Sw)以及微球的形态和硬度等性能的影响。并通过FTIR和SEM表征微球的化学结构和表面形态结构。FTIR表明硅氧键引入到聚氨酯中;SEM照片显示改性聚氨酯微球为表面多孔隙球形,直径为2 mm左右,内有空腔,空腔直径为1 mm左右。结果表明,DHPDMS质量分数为8%、分子量为4500时改性聚氨酯微球的耐水性和力学性能都有明显的提高。

The objective was to synthesize polyurethane（PU） microspheres from toluene diisocyanate（TDI）,polycaprolactone diols（PCL）,double-hydroxyl-terminated polydimenthlsiloxane（DHPDMS）,and dimethylol propionic acid（DMPA） by spontaneous emulsifying,and then followed by further reaction with triethylamine.A series of microparticles were prepared with different-NCO/-OH ratio,DHPDMS contents and molecular weight,emulsification time,CaCl2 concentration to investigate PU solution appearance,viscosity（η）,swelling ratio（Sw） and PU microspheres morphology,stiffness.Subsequently,PU microparticles obtained were characterized by FTIR spectroscopy and SEM to study PU microspheres chemical constitution and structural morphology.FTIR indicated the existent of Si-O-Si,SEM photos showed that the PU microparticles of 2mm diameter was porous on surface,and had an internal 1mm diameter cavity.In the end the results suggested that the water resistance and chemical property of modified PU microspheres were obviously improved when DHPDMS content was 8%,and its molecular weight was 4500.