On the cross‐fractionalion of copolymers

A method of theoretical analysis of copolymers fraction is described. Using the method the cross‐fractionation of copolymers is considered. It is found for copolymers of a typical molecular and composition distribution that: the differential molecular distribution curves for almost all the fractions are symmetrical in shape; most of the fractions have sufficiently broad composition distribution, the composition heterogeneity of some light fractions being especially high; the molecular distribution curves of the original copolymer constructed from the cross‐fractionation data deviate, although insignificantly, from the true curves; the composition distribution curve of the original copolymer constructed from the cross‐fractionation data deviates essentially from the true curve, but does not distort the character of composition heterogeneity of the original sample in such degree, as in the case of successive precipitation procedure. The efficiency of the procedure of the cross‐fractionation of copolymers is discussed.