Number - average molecular weight , number - average molar mass 数均分子量
With this initiating system , the number - average molecular weights of the obtained polymers increased in direct proportion with monomer conversion , and the molecular weight distributions ( mwds ) were narrow throughout the reactions ( 1 . 31 . 4 ) 将该体系应用于甲基丙烯酸丁酯的聚合反应,所得聚合物的相对分子质量分布窄( 1 . 3与单体转化率呈线性关系。