Research On Synthesis Of Polyurethane/SiO₂ Hybrid Material, Properties Of Polypropylene And Polyurethane/SiO₂ Composites

Polyurethane(PU) posseses many excellent properties such as heat resistant, oil resistant, solvent resistant, toughness, cohesiveness and flexibility;but the processability, water resistant and cold resistant are poor. Based on organic-inorganic hybrid technique, using tetraethoxysilane(TEOS) as rawal material, PU/SiO₂ hybrid materials were prepared , and the heat aging, damp aging and mechanics in low temperature of PU were improved. Using PU/SiO₂ hybrid material as mother materials to modify polypropylene(PP), PP/PU /SiO₂ composites with excellent mechanics properties were prepared. This paper included two parts:1. SiO₂ functional particles were synthesized by the the hydrolysis and polycondensation of TEOS, and the PU/SiO₂ organic-inorganic hybrid materials were prepared by the precusor of PU copolymerized with SiO₂ functional particles in stiu or by water-in-oil emulsion method. The parameters of systhesis such as material ratios, reaction temperature and time, catalyst etc., were investigated. Finally, the materials were characterized by UV, IR, DSC, TEM etc.. The results showed that the SiO₂ particles diffused in hybrid materials were linked with the PU matrix by chemical binds, and the hybrid materials had the best quality when the content of SiO₂ is 4%.2. On the view of material design, using PU/SiO₂ hybrid materials as mother materials to modify PP, PP/PU/SiO₂ composites were prepared. The mechanical property of the composites was analyzed by Tensiometry, Antibounce, SEM etc.. The results show that PU/SiO₂ hybrid materials diffused very well in PP matrix. Moreover, PP/PU/SiO₂ composites had best tensile strength when the content of PU/SiO₂ is 1%, and best impact strength when the content of PU/SiO₂ is 3%.