多检测GPC测试二醋片的分子量及其分布和特性粘度

Analysis of Molecular Weight and its Distribution and Intrinsic Viscosity of Cellulose Diacetate Flake by GPC with Multiple Detectors

采用凝胶渗透色谱(GPC)/示差(RI)/小角激光光散射(LALLS)/四毛细管示差粘度(DV)三检测器联用技术对二醋酸纤维素片(二醋片)的重均分子量(Mw)、数均分子量(Mn)、分子量分布(Mw/Mn)和特性粘度(IV)进行了测试。结果表明:①采用GPC/RI/LALLS/DV技术可以准确地测试二醋片的Mw、Mn、Mw/Mn和IV;②以软木浆和短棉绒为原料生产的二醋片的Mw、Mn较高、Mw/Mn较宽;③热解后二醋片的Mw/Mn变宽,IV降低,并有裂解分子的聚合现象。

The weight-average molecular weight （Mw）, number average molecular weight （Mn）, molecular weight distribution （Mw/Mn） and intrinsic viscosity （IV） of cellulose diacetate flake were analyzed by GPC coupled with multiple detectors, including refractometer index （RI） , low angle laser light scattering （LALLS） and four-capillary differential viscosity （DV）. The results showed that ： 1 ） Mw, Mn, Mw/Mn and IV of cellulose diacetate flake could be determined accurately by GPC/RI/LALLS/DV; 2） the Mw and Mn were higher and Mw/Mn range was wider for cellulose diacetate flake made from soft wood pulp and short cotton linter; 3 ） when cellulose diacetate flake was pyrolyzed, the Mw/Mn range became wider, IV decreased, and the pyrolyzed polymerization might emerge.