| Perfluorocyclobutyl aryl ether(PFCB)polymers are a class of novel amorphous semifluorinated polymers,which have a wide range of potential applications due to their unique properties.A new fluorosilicon structure is constructed by the conbination of the fluorine-containing structure of perfluorocyclobutyl aryl ether and the organosilicon structure of siloxane,which is a new fusion of organosilicon chemistry and organofluorine chemistry,and has important research value.In this paper,high temperature vulcanized fluorosilicone rubber containing perfluorocyclobutyl aryl ether structure was synthesized.Firstly,polyvinyl silicone oil and hydrogen silicone oil containing perfluorocyclobutyl aryl ether structure in the main chain were synthesized,and then peroxide and addition vulcanized high temperature vulcanized fluorosilicone rubber(PFCB-MVQ)were successfully prepared by using them as cross-linking agents.The main research contents and conclusions are as follows:(1)The siloxane monomer M4 containing perfluorocyclobutyl aryl ether structure was successfully synthesized,and then three kinds of silicone oil containing PFCB structure in the main chain were prepared by hydrolysis polycondensation reaction and acid-catalyzed equilibrium reaction with common silane monomers.The structure and properties of fluorosilicone oil were analyzed and characterized.The results showed that when anhydrous acetic acid was used as catalyst,reactant and solvent,and the reaction temperature was 90?,the molecular weight of PFCB-C oil was higher(Mn:6373 g/mol,PDI:1.455).In addition,TGA analysis showed that the polyvinyl silicone oil containing PFCB in the main chain obtained under the condition of anhydrous acetic acid was more stable than that obtained under the condition of NH3·H2O.Three kinds of silicone oils containing PFCB in the main chain had good low temperature resistance and were dissolved in most commonly used organic solvents at room temperature.(2)Based on the centralized crosslinking theory,the peroxy PFCB-MVQ fluorosilicone rubber was successfully prepared by using polyvinyl silicone oil with PFCB structure in the main chain(PFCB-C oil)as the concentrated cross-linking agent,and the properties of the vulcanizate were studied.The results showed that the mechanical properties of fluorosilicone rubber prepared with PFCB-C2 oil as concentrated cross-linking agent were better than those of fluorosilicone rubber prepared with PFCB-C1 oil as centralized cross-linking agent.The tensile strength,tear strength and hardness of PFCB-MVQ vulcanizate increased at first and then decreased with the increase of PFCB-C2content.When the amount of PFCB-C2 oil was 10%,the comprehensive mechanical properties of the prepared fluorosilicone rubber were the best(tensile strength:10.35 MPa;tear strength:21.78 kN/m;elongation at break:735%;hardness:72 Sh A).The thermal stability of fluorosilicone rubber prepared by adding PFCB-C oil was obviously better than that of vulcanizate prepared by common polyvinyl silicone oil,and it had good low temperature resistance and excellent hydrophobicity.(3)The additive PFCB-MVQ fluorosilicone rubber was prepared by using hydrogen-containing silicone oil with PFCB structure in the main chain as cross-linking agent,and the properties of vulcanizate were studied.The results showed that with the increase of PFCB content in cross-linking agent PFCB-H-Oil,the tensile strength and hardness of PFCB-MVQ vulcanizate increased and became stable,but the tear strength decreased.When the content of PFCB in PFCB-H-Oil was 5%,the comprehensive mechanical properties of PFCB-MVQ vulcanizate were the best(tensile strength:10.94 MPa;tear strength:28.70 kN/m;elongation at break:854%).The glass transition temperature of PFCB-H-Oil increased with the increase of PFCB content,but the Tg of PFCB-MVQ vulcanizate did not change obviously and had good low temperature resistance.PFCB-MVQ fluorosilicone rubber had good thermal stability and excellent hydrophobicity. |
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