Low-melt-viscosity polyether sulfone/polyetherethersulfone copolymers

Abstract

The rheological, mechanical, and thermal properties of random, alternating, and three block of polyether sulfone/polyetherethersulfone copolymers are compared. These copolymers have similar molecular weights and chemical composition (phenyl:ether:sulfone = 7:4:3). Differential scanning calorimetry and dynamic mechanical analysis results indicate that all copolymers possess extremely close glass transition temperature. On this basis, it is interesting to find that the alternating copolymer exhibits the melt viscosity of 281 Pa·s, which is much lower than those of random copolymer (1641 Pa·s). For block copolymers, the gradual increase with the preceding length increases in melt viscosity. In addition, the stress–strain test curves of copolymers were investigated, which revealed that sequence distribution has important influence on the tensile strengths and elongations at break. All these can be highly related to their different sequence distribution. These results obtained were discussed and interpreted.