SIMULTANEOUS DETERMINATION OF MOLECULAR WEIGHT AND COMPOSITION OF SHORT CHAIN COPOLYMER BY QUANTITATIVE SIZE EXCLUSION CHROMATOGRAPHY
定量SEC法同时测定短链共聚物的组成和分子量

he specific refractive index increments(dn/dc) of short chain polymerexhibit pronounced molecular weight dependency due to the fact that end groupcontributes much to the optical property of whole polymer chain. From the weightfraction additivity rule.(da/dc) of the whole polymer chain is the sum of thoseof corresponding structural units and it is indicated that changing the end group ofa given polymer,the molecular weight and (da/dc) of the polymer chain stem could be determined simultaneously by measuring (da/dc) of the whole polymers. Itis also possible to estimate the composition of the copolymer from (dn/dc) of the chain stem. This principle especially applicable to short chain polymers with pronounced end group effect.This principle is checked by quantitative size exclusion chromatography to measure (da/dc) of the benzene solution of oxyethylene-oxypropylenecopolymer with different end groups and satisfactory results are obtained.A method for simultaneously estimation of the molecular weight and composition of short chain copolymer by measuring (da/dc) of the sample solution withquantitative SEC was proposed.