聚硅氧烷改性环氧衣康酸酯水性UV固化树脂的制备及性能

Preparation and Properties of Waterborne UV Curable Epoxy Itaconate Resin Modified by Polysiloxane

利用端氢聚硅氧烷改性环氧衣康酸酯(IE)树脂,将所得聚硅氧烷改性环氧衣康酸树脂(SiIE)与半封端异氰酸酯中间体接枝共聚,制得聚硅氧烷改性半封端异氰酸酯环氧衣康酸酯树脂(IPDIHSiIE)。采用红外光谱(FT-IR)、核磁氢谱(~1H NMR)表征了IPDIHSiIE的化学结构,考察了聚硅氧烷用量对改性树脂及漆膜理化性质的影响。实验结果表明:聚硅氧烷与IE树脂在90℃下8 h可反应完全,通过硅氢加成可成功制备目标产物。随着聚硅氧烷用量的增加,改性树脂水分散体的粒径逐渐增大,贮存稳定性变差,凝胶率先上升后下降,当聚硅氧烷用量为5%时,水分散体的Z均粒径为129.8 nm,水分散体呈半透明,贮存一个月无明显变化,凝胶率达到最大,为93.1%。漆膜的疏水性能随聚硅氧烷用量的增加而提高,改性漆膜具有良好的热稳定性能;随着聚硅氧烷用量的增加,漆膜的铅笔硬度和柔韧性得到提高,附着力略有下降,玻璃化转变温度逐渐下降。

Semi⁃terminated isocyanate epoxy itaconate resin modified by silicone(IPDIHSiIE)was synthesized by graft copolymerization of polysiloxane modified epoxy itaconate resin(SiIE)that was prepared from the reaction between hydroterminated polysiloxane modified epoxy itaconic acid ester resin and half⁃terminated isocyanate.The chemical structure of IPDIHSiIE was characterized by FT⁃IR and 1 H NMR.Effects of the amount of polysiloxane on the physical and chemical properties of the modified resin and the film were investigated.The results showed that the reaction between polysiloxane and epoxy itaconate resin was completed at 90℃for 8 h,indicating that the target product could be successfully prepared by silicohydride addition.With the increase of the amount of polysiloxane,the particle size of the modified resin dispersion gradually increased,the storage stability became worse,and the gel first risen and then fell.When the content of polysiloxane was 5%,the Z⁃mean particle size of aqueous dispersion was 129.8 nm,the aqueous dispersion was translucent and had no obvious change after storage for one month.Meanwhile,the gel rate reached the maximum of 93.1%.The hydrophobic property of the modified film was improved with the increase of polysiloxane content,and the film had good thermal stability.With the increase of polysiloxane content,the pencil hardness and flexibility of the film were improved,the adhesion decreased slightly and the glass transition temperature decreased gradually.