Reproducibility of crosslink distribution in polysaccharides crosslinking depends on the homogeneity of the reaction mixture. If the condition of reaction homogeneity is met, the distribution of substituents (or crosslinks) should directly determine the relative reactivities of the functional groups. The resulting molecular size distribution of fragments of monosaccharide units connected by crosslinks in such a case should be given by the statistical laws of network formation. This principle is exemplified on amylose crosslinked by epichlorohydrin in a homogeneous water-alkali medium. The relative reactivities of functional groups are investigated in two ways: 1) by specific reactions; 2) calculated theoretically from the molecular size distribution of fragments of crosslinked glucose units. Good agreement of both results supported the above mentioned assumptions. The reactivity of amylose hydroxyls increases strongly in the order OH-3

Molecular size distribution in multichain polymers formed by polyfunctional homopolymerization of a single kind of repeat unit is calculated theoretically. An expression was derived for the weight fraction distribution of isomers of certain composition of units defined by a vector u. Molecular size distribution equations were derived explicitly as functions of link distribution. A formula was deduced for the link distribution, more generally than it was done for a linear substitution effect.

From the results of a structural analysis of cellulose crosslinked by a bifunctional reagent conclusions can be drawn merely on the distribution of crosslinks among individual hydroxyl groups. No information is available to what extent this distribution is caused either by different relative reactivities ofthe hydroxyl groups or incomplete accessibility of glucose units. If each glucose unit had the same chance of reaction, at low levels of conversion only monosubstituted units should be present in the reaction product. If, however, some higher substituted units are present, this means that at a certain level ofconversion there must have been a smaller number of units capable of reaction to which relatively more reagent had access. The relation between relative reactivity and accessibility of cellulose hydroxyl groups obeys certain statistical laws of random selection. A theory explaining these laws is developed in the present work and supported by good agreement with experimental results exemplified by microcrystalline cellulose crosslinked by epichlorohydrin (1 -chloro-2,3-epoxypropane). The relative reactivities of cellulose hydroxyls were found to increase in the order OH-3, OH-6, OH-2 in the crosslinking reaction with epichlorohydrin. dl Part 2: cf.'). h, Systematic IUPAC name: l-chloro-2,3-epoxypropane.

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Correlations between weight and number fraction distributions of a reaction mixture obtained by polyfunctional homopolymerization of a single kind of repeat unit under postgelation conditions are derived by virtue of an inter‐ and intramolecular bonds balance. An expression for the number average degree of polymerization was derived by means of the probability generating function of the first generation. Number fractions of a specific group of topologically distinguishable structures corresponding to a certain class of molecular trees defined by a vector u may be calculated in this way. Relations were established in terms of the link distribution function which allows for a substitution effect. Gelation phenomenon is shown to cause the number distribution mathematical relations to take two different forms while the weight fraction distribution equations remain valid throughout the whole conversion range.