Synthesis of crosslinker containing fluorine to maintain fluorine content during fluorosilicone curing

초록

In order to improve the fluorine content during fluorosilicone curing, we plan to increase the fluorine in crosslinker that we product. For this reason, we set up various reaction conditions prior to the experiment. For crosslinker, we use octamethylcyclotetrasiloxane(D4), tetramethylcyclotetrasiloxane(HD4), 1,3,5-Tris[(3,3,3-trisfluoropropyl)-methyl]cyclotrisiloxane(FD3) are required, and hexamethylsiloxane. The reason why 1,3-divinyltetramethyldisiloxane(Vinyl End-blocker) and ViD4 are not used is that during curing Si-H group in HD4 and vinyl group in those materials can be cured itself. We set up the various conditions such as FD3:D4 ratio, initiator amount and reaction time. First, we put all of the materials in reactor except HD4 Then, we add HD4 in small amounts for 30min through the dropping funnel because it has so much high reactivity. In some cases, the reaction was so explosive that we stopped the reaction. After adding the initiator, the reaction is carried out for 2 hours, and then we add end-blocker for termination. For the reaction, the reaction temperature is maintained at 90oC. Finally, we make the reactor vacuum through aspirator for removing the unreacted materials and by-products from back-biting phenomenon