A formaldehyde free co-binder solution formed by using a polyol to crosslink polycarboxylic acid and a polyacid monomer is provided. In forming the co-binder solution, the polyacid monomer and the polyol are mixed in any conventional device with heat and agitation for a period of time sufficient for the chemicals to react and form a reaction product. The resultant product is then admixed with polycarboxylic acid to form a co-binder solution. In a preferred embodiment, the polyacid is maleic anhydride and the polyol is triethanolamine.