Cationic Polymerization of (3-Aminopropyl)-trisfurfuryloxysilane Derivatives-a New Strategy for Complex Hybrid Material Synthesis

摘要

The trifunctional (3-aminopropyl)-tris-furfuryloxysilane monomer (1) is able to undergo both twin polymerization and reaction with electrophilic compounds such as isocyanates. 1 can be readily synthesized from 3-aminopropyptrimethoxysilane (APTMS) and furfuryl alcohol (FA). The reaction of 1 with three different aromatic isocyanates, namely phenyl isocyanate, diphenylmethane- 4,4'-diisocyanate (MDI), and a prepolymer consisting of MDI end-capped polytetramethylene ether glycole (PTMEG), to the corresponding substituted urea derivatives is presented. Three urea derivatives 1-phenyl-3-(3-tris-furfuryloxysilyl) propylurea (2), diphenylmethan-4,4'-bis3(tris-furfuryloxysilyl)propyl urea (3), bis3(tris-furfuryloxysilyl)-propylurea-capped PTMEG-MDI-prepolymer (4) as well as 1 were polymerized to multicomponent organic/inorganic hybrid materials in a one step procedure using methane sulfonic acid as catalyst. The simultaneous formations of poly furfuryl alcohol and polysiloxane networks within the hybrid material are proven by means of solid-state NMR spectroscopic measurements. The homogeneous distribution of silicon within the solidified hybrid materials is analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy, and high-angle annular dark field-scanning transmission electron microscopy (HAADF)-STEM. Homogeneous nanostructured hybrid materials with silicon cluster sizes in the range of 2 nm have been obtained by polymerization of the urea derivatives 2, 3, and 4.