A melamine ring containing copolymer and a method of manufacturing a melamine ring containing copolymer are described. The method includes mixing melamine and cashew nut shell liquid, heating the mixture, and reacting the mixture for about 4 to 6 hours. The melamine ring containing copolymer can have a dynamic viscosity of about 0.5.times.10.sup.4 P to about 3.times.10.sup.4 P or a viscosity that continues to increase upon heating.