二氧化碳共聚物的分子量表征(GPC和特性粘数法)

MOLECULAR WEILGHT CHARACTERIZATION FOR CO_2 COPOLYMERS BY GPC-INTRINSIC VISCOSITY METHOD

脂肪族聚碳酸酯的分子量表征问题可以从GPC数据阳特性粘数较迅速可靠地解决,同时求出其数均,粘均,重均,动力学平均分子量,及其分子量—特性粘数关联参数。为此须对以往方法作较大的改进,其关键是用迭代法进行特性粘数(dL/g)与分子量的关联。如此对聚碳酸亚丙酯和碳酸亚乙酯分别得到以下关系: ln(η)=-6.671+0.328ln(?)v+0.0186(ln(?)v)~2 (25℃,THF) (η)=6.64×10^(-5)(?)v^(0.76) (25℃, CHCl_3)

Molecular weight characterization for aliphatic polycarbonates can be accomplished by evaluation of GPC and intrinsic viscosity data to give simultaneously the number-, viscosity-, weight-,Z-average molecular weights, the hydrodynamic molecular weights, in addition to the parameters for the intrinsic viscosity-molecular weight correlation. The calculation procedures were significanlty improved with the key process of trial and error test for the intrinsic Viscosity ((η) dL/g)-viscosity-average molecular weight (_y) correlation. Thus satisfatory correlations were obtained for poly-(propylene carbonate) and poly(ethylene carbonate) respectvely; In (η)=-6.671+0.3281n_v+0.0186(In_v)~2 (25℃, with THF) (η)=6.64×10^(-5)_v^(0.78) (25℃, with CHCl_3)