Closed‐Loop Phase Behavior and Baroplasticity of deuterated Polystyrene‐block‐Poly(n‐pentyl methacrylate) Copolymer investigated by SANS and FTIR Spectroscopy

Abstract

AbstractThe closed‐loop phase behavior of deuterated polystyrene‐block‐poly(n‐pentyl methacrylate) copolymer (dPS‐PnPMA) was investigated by small‐angle neutron scattering (SANS) and temperature‐dependent Fourier transform infrared (FT‐IR) spectroscopy. The effect of hydrostatic pressure on the transition temperatures was studied by using SANS. We found that dPS‐PnPMA has large pressure coefficients of transition temperatures (dT/dP = ±725 °C/kbar). Since this block copolymer exhibited excellent baroplastic property, it was easily molded into a desirable shape at a relatively low temperature under medium pressure. On the other hand, commercially available polystyrene‐block‐poly(ethylene‐co‐butylene)‐block‐polystyrene copolymers were not molded at the same processing condition. Finally, we investigated the driving force inducing the closed‐loop phase behavior by using temperature‐dependent FT‐IR.