Synthesis, characterization, and optical properties of polymers comprising 1,4-dithiane-2,5-bis(thiomethyl) group

Abstract

ABSTRACT:To obtain an optical polymer with a high refractive index ( n D ) and Abbe's number (n D ), a series of 1,4-dithiane-2,5-bis(thiomethyl) (DBT) group-bearing poly( Salkylcarbamate) and polyvinylsulfide were synthesized by the polyaddition of 2,5-bis(mercaptomethyl)-1,4-dithiane (BMMD) with diisocyanates and by the addition polymerization of 2,5-bis(2-thia-3-butenyl)-1,4-dithiane (TBD) in bulk, respectively. Their n D : n D values, ranging from 1.598 : 38.2 to 1.678 : 34.8, are comparable to those of flint glass. Some of the polymers having a high transparency and glass transition temperature were suggested to be useful as optical polymers. The DBT group contribution to the increase of the n D value of the obtained polymer was explained in terms of the f value defined by the ratio of molar refraction to molar volume and was concluded to be of primary importance because the value for the DBT group (0.38) was greater than that for the residual group making up the polymer structure. This group's contribution in preventing the degradation of the n D of the polymers was also discussed based on the UV spectrum of BMMD, which only showed a suppressed absorption band. BMMD and TBD are useful monomers for preparing an optical polymer with high n D and n D values.

Development of High Refractive Index Plastics

“…At present, PTUs are being experimented for various uses such as lenses, prisms, optical fibers, optical filters, information recording medium and light emitting diode [26][27][28][29][30][31][32][33]. Polysulphones have a high refractive index of 1.634 -1.675 and are desirable for many lens applications as they can be easily cast into thin lenses.…”

“…Sulfur containing monomers are good candidates for producing high refractive index optical materials; ready polarizability of a sulfur produces a strong interaction between the material and incident light, resulting in high refractive index [55]. Sulfur containing polymers including polythiourethanes are therefore, nowadays, being developed as optical materials because of their high refractive index [26][27][28][29][30][31][32][33].…”

“…The polythiourethanes have a high refractive index, low dispersion of refractive index and they are light weight, colorless and transparent [26][27][28][29][30][31][32][33]80]. Aliphatic or alicyclic polyisoyanates have been used alongwith thiol compounds to prepare high refractive index optical plastics having a refractive index greater than 1.60.…”

Research on Preparation, Structure and Properties of TiO2/Polythiourethane Hybrid Optical Films with High Refractive Index

“…It has been exploited in many industrial fields such as coatings, adhesive, sealant and lenses. [30][31][32][33] Moreover, PTU polymers have a relative higher refractive index than conventional PU materials due to the introduction of sulfur. [32,33] Thus it is interesting that titania was incorporated into high refractive index PTU to fabricate a higher refractive index hybrid materials.…”

“…[30][31][32][33] Moreover, PTU polymers have a relative higher refractive index than conventional PU materials due to the introduction of sulfur. [32,33] Thus it is interesting that titania was incorporated into high refractive index PTU to fabricate a higher refractive index hybrid materials. In this paper, we designed a high refractive index polythiourethane polymer with the pendant triethoxysilane groups on the side chains and then it was incorporated into titania sol to synthesize a series of transparent hybrid thin films with high refractive index (Scheme 1).…”