In various embodiments the present invention comprises 2,4,6-trisubstituted-1,3,5-triazine capping agents comprising one, two, or three leaving groups as substituents with any remaining substituents being essentially inert to reaction with a nucleophilic group on a polymer or monomer, or reactive with a nucleophilic group on a polymer or monomer at a slower rate than any leaving group. The invention also comprises polymers or monomers with nucleophilic groups capped with a triazine moiety. Still other embodiments of the invention comprise processes for capping nucleophilic groups in a polymer or monomer which comprises combining and reacting the polymer or monomer with a triazine-comprising capping agent.