Key Monomer Of High Refractive Index Surfur-Containing Optical Resin-Synthesis, Characterization And Properties

Polymer optical materials have been widely applied in the realms of eyeglass,building materials, adornment, auto light, etc, owing to their excellent performances inoptical property, weight, impact resistance, machinability, and abrasive resistance. Thistraditional glass has been replaced by polymer optical material in most areas especiallyin eyeglass industry. Now CR-39resin is the main material used for eyeglass on themarket, but its refractive index is only1.50. In order to make the eyeglass thinner andlower curvature, the refractive index of polymer optical material must be improved.In this thesis, we synthesize a thiirane resin with high refractive index and Abbenumber in the way that brings in sulfur in the form of sulfydryl and thiirane tomesitylene. The reaction steps are as follows. Firstly, bromo mesitylene withN-bromosuccinimide to get1,3,5-tribrooethyl benzene (A1). Secondly, throughthiourea hydrolyzing alkylation, we obtain1,3,5-trithiomethyl benzene (A2). Thirdly,through the ring-opening and ring-closing reactions with epichlorohydrin to get1,3,5-tri sepithiopropylthiomethyl benzene (A3). Finally,1,3,5-tri(thiiran-2-ylmethylthio)methyl benzene (A4) is synthesized by the reaction of the exchangement betweenoxygen and sulphur. Compound A1~A4are characterized by FT-IR, NMR and MS.Then checkout the refractive index of A4is1.662, Abbe’s number is46. And we alsocheckout the mass loss of A4, T5%=111℃, T10%=171℃, Tmax=289℃, these show thatA4is not thermo stability.We also researched the conditions of polymerization include hardener, temperature,air bubble and mold. At last, we used A2as hardener, and heat A4in glass orpolytetrafluoethylene mold at70℃~120℃to form optical polymer A5. Then testedthe performance of A5in light transmission, stability, surface hardness, etc. We got data as follows. The refractive index of A5is1.671, Abbe’s number is31, at thisproperty we achieved the goal. Ultraviolet-visible transmission of A5is89%, which isclose to theoretical value. Surface hardness reach5H, higher than CR-39. Density is1.251g/cm~3, lighter than glass. The data of TG and DMA show that A5has excellentthermo stability. And the maximum moisture rate of it is only0.112%, compared withothers, it’s preeminent.