1) Chemical property 
If one of the monomers in a copolymerization has a functionality greater than 2, a branched copolymer can be formed. It is also possible for the branches to react and create cross-links. In this way, `infinite” polymer networks called gels are made. Definitions: PA = probability that A reacts PB = probability that B reacts NAo = original numbe.....
the stage at which a liquid begins to exhibit pseudoelastic (jellylike) properties NOTE - This stage may be conveniently observed from the inflection point on a viscosity-time plot.