【摘要】 1.本文叙述所用渗透计及测定方法,在实验技术方面,討論半透膜對溶剂的透过性在使用中的變化,和在渗透计上半透膜在测定进行中可能有的变形。 2.又曾用九個丁苯橡膠级份的甲苯溶液在25°時作了渗透壓测定,得到的数據π/C对C是非線性的,但是可用（π/C）^1/2對C作线性外推,得到M_n和A₂的数值,且A₂M_n/[η]为一常数。 3.從粘度及渗透壓数據,得到: [η]=1.25×10^-4M^0.78分升/克（甲苯溶液,30°）所得a值较前人测定的为高,并在文中加以詮釋。更多还原

【Abstract】 The molecular weights of nine fractionated samples of butadiene-styrene copolymer were determined osmometrically in toluene at 25°. Experimental technique for the use of osmometer and the swelling of cellophane membrane in 5—30 pct NaOH solutions have been described. The change of permeability during repeated use of the membrane and its possible deformation during a determination were discussed.π/C vs C plots for the system studied are non-linear, while the experimental data permitted linear extrapolation on （π/C）^1/2 vs C plots to give M_n and A₂ values. The ratio A₂M_n/[η] was found to be a constant, independent of M_n.The[η]-M relation obtained is [η]=1.25×10^-4M^0.78dl/g in toluene at 30°. The somewhat higher value of a obtained is explained by the fact that previous workers applied linear extrapolation on π/C vs C plots and the possible branching of the samples used was neglected.更多还原