Free-radical polymerization is irreversible, and the primary chains formed earlier are expected to possess larger branching density compared with those formed later, leading to a branching density distribution (BDD) among primary chains. In addition to the BDD, the primary chain length distribution (CLD) may change during polymerization. For a primary CLD with a shift toward smaller chain length during polymerization, the expected g-ratio for a given number k of branch points can be approximated reasonably well with that for the random branched polymers having the accumulated primary CLD. On the other hand, when the primary CLD moves toward larger chain length during polymerization, the expected g-ratio may become smaller than the corresponding random branched polymers, due to an “unnatural” combination in the length of backbone and branch chains. The compactness of branched architecture could be controlled through the consideration of the maximum end-to-end path length.

中文翻译：

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分批自由基聚合链转移到聚合物中支化点分布对回转半径的影响

自由基聚合是不可逆的，预期较早形成的主链与后形成的主链相比具有更大的支化密度，从而导致主链之间的支化密度分布（BDD）。除BDD外，聚合过程中主链长度分布（CLD）可能会发生变化。对于在聚合过程中向较小链长转移的初级CLD，对于给定数目的k个支化点，预期的g比可以与具有累积的初级CLD的无规支链聚合物的合理地很好地近似。另一方面，当初级CLD在聚合过程中移向更大的链长时，预期的g由于主链和支链长度的“非天然”组合，比值可能会比相应的无规支链聚合物小。分支架构的紧凑性可以通过考虑最大的端到端路径长度来控制。