Preparation And Research Of The Epoxy Resin/Amino-polysiloxane/Nano Silica Adhesive

The octamethylcyclotetrasiloxane and the N — ( βγ — aminoethyl) — γ —aminopropylmethyldimethoxysilane were chosen to prepare aminopolysiloxane with different amino number and different inherent viscosity by anion bulk polymerization. In this course, KOH was chosen as catalyst, the dimethyl sulfoxide was utilized as accelerating agent, and the hexamethyldisiloxane was used as end capping agent. Then, different formula ratio and different curing condition were used to prepare the adhesive composed of Epoxy resin / aminopolysiloxane/ nano silica. In the process of the preparation, the time, temperature, catalyst and the accelerating agent were analyzed. The following was the optimal condition: the temperature was 90℃, time was 8h, the catalyst's quantity was 0.12%(relative to the active principle of the reagent), the accelerating agent's quantity was 0.2%(relative to the active principle of the reagent),.and the coupling agent's quantity was 5% more than the octamethyl-cylotetrasiloxane. In the case of the preparation of the epoxy resin / aminopolysiloxane adhesive, we studied the influence of all the variable on the mechanic performance and adhesive performance such as the time, the temperature, the ratio of the epoxy resin to aminopolysiloxane, the amino number, inherent viscosity of the aminopolysiloxane, the kinds of cure agent, the curing time, the curing temperature and the kinds of epoxy resin. The best result was obtained when the time was 2.5h, the temperature was 100℃, the content of the aminopolysiloxane was 20%, the amino number of the aminopolysiloxane was 2.3mmol/g, the inherent viscosity of the aminopolysiloxane was 1.18 dl/g, the epoxy resin was the blending of E-44 and E-51 (30:70), the cure agent was 4,4'-diamiondiphenyl methane (MDA), the curing condition was 25℃/3h + 120℃/2h. In addition, we studied the influence of the addition of nanometer SiO₂ on the performance of epoxy resin/aminopolysiloxane/nano silica adhesive. The experimental result witnessed that the addition of nanometer SiO₂ would improve the performance of the adhesive. What's more, the adhesive performance was also influenced by the content of the nano silica in the adhesive. When the nano silica content in the adhesive was 3%, the tensile shear adhesive strength improved 4.17 Mpa, and the thermo decomposition temperature improved 72...