Critical solution point and chain dimension of branched-polystyrene solutions

Summary

Critical solution point and chain dimension were measured for branched polystyrene(BPS) in solution as a function of molecular weight(M) and compared with those for linear polystyrene(LPS). The critical concentration φ_c of BPS was quite different from that of LPS at a fixed M, but the same at a fixed overlap-concentration φ^*, i.e., plots of φ_c vs. φ^* fall on a single straight line for both BPS and LPS (gf_c ∝ φ^*). Reduced critical temperature τ_c defined by gt_c=(θ−T_c)/θ [T_c: critical temperature, θ: the θ-temperature] was related to φ_c as τ_c ∝ φ_c ^∼2 for BPS, whereas τ_c ∝ φ_c for LPS.