Determination of reaction mechanisms and evaluation of flame retardants in wood-melamine resin-composites

Extrudable wood-melamine resin-composites with up to 70% wood content are a novel material with numerous advantageous properties. Reduction of the flammability of this material is a precondition of many potential applications. Based on the state of the art a flame retardant system with sufficient fire resistance was developed and characterised. Understanding of the flame retardance mechanisms, pyrolysis and burning processes was achieved by investigation of the pyrolysis products, reaction temperatures, reaction enthalpies and determination of the proportions of solid, liquid and gaseous pyrolysis products.The well-known reaction mechanism of acidic degradation of phosphorus-based flame retardants was verified with these methods. Interesting new results were obtained with boron-based flame retardants. These compounds act in different ways which explains the good flame protection of the composites. Dependent on the type of boron compound used we found a combination of reaction mechanisms: on the one hand acidic degradation and on the other hand protection by formation of a tight barrier.