Abstract:

By using a combination process of precipitation and extraction and modification by silane coupling agent A174, a 15% nano-silica polyether diol dispersion was prepared,which was directly used as raw material to react with polyether diol( poly(propylene glycol)),isophorone diisocyanate (IPDI), 2, 2-Dimethylol propionicacid(DMPA), trimethylol propane (TMP), triethylamine (TEA), ethylene diamine(EDA) to synthsize a serious of modified WPU samples with different nano-SiO₂ particle content. The influence of the amount of nano-SiO₂ on the properties of emulsion and coating film was studied. The results showed that the nano-SiO₂ modified polyether diol and prepolymer were reacted; the dispersion of modified SiO₂ in the waterborne polyurethane was good when the amount of nano-SiO₂ was 2% of prepolymer, leading a stable waterbome polyurethane dispersion, with a film elongation at break 300%, tensile strength 13 MPa, and improved water resistance, hardness thermal stability.

Key words: nano-silica, waterborne polyurethane, precipitation and extraction process

摘要： 采用沉淀和萃取相结合，硅烷偶联剂 A-174 包裹改性的方法，制备了改性的纳米二氧化硅含量为 15%的聚氧化丙烯二醇分散液，并以其直接作为原料，与聚丙二醇(PPG)、异佛尔酮二异氰酸酯(IPDI)、2，2-二羟甲基丙酸(DMPA)、三羟甲基丙烷(TMP)、三乙胺(TEA)、乙二胺(EDA)等其他原料，制备了一系列纳米 SiO₂ 粒子改性 WPU 样品。 讨论了改性纳米 SiO₂ 加入量对乳液和涂膜性能的影响。 研究表明:纳米 SiO₂ 聚醚二元醇分散液与预聚物发生了反应，纳米 SiO₂ 均匀分散在预聚物中，乳化后，纳米 SiO₂ 粒子在水性聚氨酯中分散性变好，纳米 SiO₂ 用量为预聚物质量的 2.0%时，得到了稳定的纳米二氧化硅水性聚氨酯分散液，复合涂膜的断裂伸长率为 300%，拉伸强度为 13 MPa，耐水性、硬度、热稳定性得到较大的提高。

关键词: 纳米二氧化硅, 水性聚氨酯, 沉淀和萃取法