Multi-chain Polymerization
A monomer with functionality 3 has 3 functional groups which participate in the polymerization. This will introduce branching in a polymer and may ultimately form a cross-linked macrostructure. The point at which this three-dimensional network is formed is known as the gel point, signaled by an abrupt change in viscosity.
A more general functionality factor fav is defined for multi-chain polymerization, as the average number of functional groups present per monomer unit. For a system containing N0 molecules initially and equivalent numbers of two function groups A and B, the total number of functional groups is N0fav.
And the modified Carothers equation is
- , where p equals to
Read more about this topic: Step-growth Polymerization