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

摘要: 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(M_w)、数均分子量(M_n)、分子量分布(M_w/M_n)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M_w、M_n、M_w/M_n和IV;②以软木浆和短棉绒为原料生产的二醋片的M_w、M_n较高、M_w/M_n较宽;③热解后二醋片的M_w/M_n变宽,IV降低,并有裂解分子的聚合现象。

Abstract: The weight-average molecular weight(M_w),number average molecular weight(M_n),molecular weight distribution(M_w/M_n) 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) M_w,M_n,M_w/M_n and IV of cellulose diacetate flake could be determined accurately by GPC/RI/LALLS/DV;2) the M_w and M_n were higher and M_w/M_n range was wider for cellulose diacetate flake made from soft wood pulp and short cotton linter;3) when cellulose diacetate flake was pyrolyzed,the M_w/M_n range became wider,IV decreased,and the pyrolyzed polymerization might emerge.