Soluble and Thermally Stable Polysulfones Prepared by the Regiospecific and Alternating Radical Copolymerization of 2,4-Hexadiene with Sulfur Dioxide

Abstract

We synthesized the alternating copolymers of 1,3-diene monomers with sulfur dioxide (SO 2 ) as a new class of thermally stable polymers by the radical copolymerization process and the subsequent hydrogenation. The copolymerizations of 2,4-hexadiene (HD), 1,3-butadiene (BD), and isoprene (IP) with SO 2 were carried out at -78 to 0 °C in toluene in the presence of tert-butyl hydroperoxide, which acts as one component in the redox initiating system in combination with SO 2 . The resulting poly(diene-alt-SO 2 )s were found to consist of highly controlled repeating units, that is, an alternating and 1,4-regiospecific repeating structure. Poly(HD-alt-SO 2 ) was soluble in several organic solvents, such as chloroform, nitromethane, tetrahydrofuran, acetone, and dimethyl sulfoxide. In contrast, poly(IP-alt-SO 2 ) was soluble only in dimethyl sulfoxide, whereas poly(BD-alt-SO 2 ) was insoluble in all of the solvents. The poly(diene-alt-SO 2 )s readily degraded upon heating because of the expected fast depolymerization. We have demonstrated that the thermal stability of the poly(diene-alt-SO 2 )s is modified by the hydrogenation of the double bond in the polymer main chain. The hydrogenation of poly(HD-alt-SO 2 ) resulted in a drastic increase in the 5% weightloss temperature from 135 to 317 °C.

Tunable thermal degradation and refractive index of poly(norbornene sulfone)s via two different polymerization methods

“…The T95 and T50 value were increased from 255 to 283 °C and from 310 to 315 °C, respectively. A glass transition temperature ( T g ) determined by DSC measurement are 252 and 267 °C (Figure ), and the scission of the CS bond in the main chain first occurs below 200 °C, the more complicated polymer decomposition occurred in the temperature region over 200 °C. In the experiment of the polymerization, the free radical polymerization is easy to local overheating, resulting in uneven distribution of molecular weight, and the coordination polymerization molecular weight distribution is more uniform.…”

A new addition to the family of polyesters—Synthesis and characterization of novel (alternating) poly(ether ester)s, poly(butylene 3-/4-hydoxy benzoate)s

“…The unsaturated double bonds in UPEEs were reduced using TSH to yield PBHBs as shown in Scheme 2. TSH has been used for the reduction of unsaturated double bonds in polybutadienes and other polymers carrying unsaturated bonds before [7][8][9][10][11][12][13][14][15][16].…”

Kinetics and mechanism of the thermal degradation for the synthesis of poly(norbornene sulfone)s by two different polymerization methods

“…In recent research, various kinds of polymers have been synthesized by copolymerization of SO 2 with unsaturated hydrocarbons, such as vinyl butyl carbonate, norbornene, styrene, propylene oxide, diene, and vinyl chloride, [2][3][4][5] and the formed polymers with high transparency, low dielectric constants, excellent chemical resistance, and good barrier properties, which are used as etching resists, transient electronic packaging, and drug delivery vehicles. [6][7][8][9] But different research groups choose different ways of polymerization, such as free radical polymerization, cationic polymerization, and coordination polymerization. [10,11] Effect of different polymerization methods on the copolymerization of olefins and sulfur dioxide has not been studied yet.…”