Structure-based Polymer Representations

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Structure-based polymer representations enclose only a portion or a structure within brackets. One or more bonds cross each of the enclosing brackets. The crossing bonds "match up", making the polymer structure more explicit.

You create a structure-based polymer representation by enclosing a portion of a structure in brackets with a bracket type of SRU (n). The subscript "n" is recommended by IUPAC to notate structure-based representations of unknown size, but you can edit the text using the text tool.

A structure-based representation of poly(vinyl chloride) is shown below.

You can also use the Bracket Usage types "Crosslink (xl)", "Graft (grf)", and "Modification (mod)" to represent specific types of repeating units in a structure-based representation, but they are rarely encountered and using them is discouraged.