Preparation And Properties Of Halogen Free Flame Retardant Addition Type Room-temperature Vulcanized Silicone Rubber

In this thesis，the synthesis conditions of methyl vinyl polysiloxane，the effects on themechanical properties of addition silicone rubber were studied.And the silicone rubber withgood mechanical properties was prepared; Then, on this basis, synthesized a new graftmacromolecular modifier PDMS-g-TEOVS and used it to modify aluminum hydroxidewhich be used as flame retardant，and obtained the flame retardant silicone rubber with goodmechanical properties, which the vertical flame test rating FV-0.The main contents of thispaper are as follows:In this paper, we first studied the methyl vinyl polysiloxane synthesis conditions, andfound that when using tetramethyl ammonium hydroxide as a catalyst for polymerization,the relationship of catalyst concentration on polymerization rate was1/2; when the amountof catalyst was0.015%, the temperature was100℃, only need0.5h, the reaction conversioncould reach to88.7%. The effects of the vinyl content of methyl vinyl silicone rubber,hydrogenous silicone oil on the mechanical properties were reviewed. Results show that thetensile strength and the tear strength could reach6.7MPa and33.1kN/m respectively in thepresence of100phr methyl vinyl silicone rubber with the vinyl content being0.16%,4phrhydrogen silicone oil with the hydrogen content being1.0%,0.05phr Karstedt catalyst and40phr amorphous silica.Using aluminum hydroxide as flame retardant to prepared flame retardant siliconerubber, when the addition of aluminum hydroxide was80phr, LOI of the flame retardantsilicone rubber could reach to37.5%and the vertical flame test rating FV-0. But addingunmodified aluminum hydroxide could badly damage the mechanical properties of flameretardant silicone rubber. In order to improve the mechanical properties of flame retardantsilicone rubber, using hydrosilylation reaction to synthesis a new graft macromolecularmodifier PDMS-g-TEOVS and used it to modify aluminum hydroxide, the results show thatafter the macromolecular modified, the tensile strength of flame retardant silicone rubberincreased20%, to reach4.91MPa, and the tear strength increased30%, up to21.7kN/m.the modification effect better than silane coupling agent A-151.