Scientific study activities and laboratory research and development allow us to update our formulations daily.
CORIUM project by Borma Wachs
As part of the CORIUM project, new formulations for the functional protection of wood have been studied and developed, the result of advanced research in the field of flame retardant, intumescent materials, anti-UV and anti-scratch nanomaterials.
The acronym for the CORIUM project is a Latin word that means “leather”, “bark”, “protective layer” symbol of the general objective of research activities focused on the development of high-tech chemical specialties for the protection of wood.
Particular attention was paid to the topic of nanocomposites, a class of materials with significantly improved properties. The fundamental understanding of how two dissimilar materials interface on the nanoscale has huge implications for macro-scale performance and properties. Therefore, the study of polymeric nanocomposites is not limited to capturing the media hype of nanotechnology, but concerns the understanding of structure-property relationships and the science of molecular and macromolecular scale interphases.
Applications of nanostructured additives
Historically, Toyota developed the first polymer nanocomposites by adding clay nanostructures to a polyamide-6 (nylon-6) polymer for automotive applications. The improved high temperature resistance of the nanocomposite allowed it to be used as part of the engine, resulting in weight savings in a machine. Additional initial applications for nanocomposite technology have included improved gas barrier properties (food and beverage packaging), electrical conductivity for electromagnetic applications and increased mechanical strength and toughness for engineering use.
Flame retardant properties of nanomaterials
Flammability applications for polymer clay nanocomposites have been recently discovered, and the CORIUM project has been focused on industrial research and development in the wood sector for furniture, coatings and construction. Polymer nanocomposites for flammability applications are interesting because the formation of a nanocomposite not only improves the properties of fire but also improves other properties (for example, mechanical properties), leading to the concept of multi-functionality of materials.
As part of the project, the concepts of “gradient structure” and “nanostructured micrometric particles” were also addressed, focusing on the need to avoid the use of nanoparticles and nanopowders, whose danger to human health and the environment is not it has still been sufficiently studied. For this reason, the new Borma Wachs formulations use nanomaterials and REACH registered substances.
Although flame retardants can differ from each other in terms of chemical structure, some general mechanisms of action are applicable to various classes of flame retardants. The first separation line normally distinguishes flame retardants active in the gas phase and in the condensed phase. The flame retardants active in the gas phase mainly act through the inhibition of free radicals responsible for the radical chain reactions in the flame. This is the chemical mechanism of action in the gas phase. Other flame retardants generate large quantities of non-combustible gases, which dilute flammable gases, sometimes dissociate endothermically, decrease the temperature by absorbing heat. This slows down combustion and may eventually cause the flame to extinguish. This is the physical mechanism of action in the gas phase.
The condensed phase action mechanisms are more numerous than those of the gas phase. Carbonization is the most common condensed mode of action. Again, carbonization could be promoted by chemical interaction of the flame retardant with the polymer phase or by physical polymer residues in the condensed phase. Carbonization could also be promoted by catalysis or oxidative dehydrogenation.
Nanomaterials vs nanostructured micrometric materials
Some additives in the form of nanoparticles dispersed in polymers have an effect of delaying and reducing the flame due to the formation of carbon layers, the labyrinth effect and the depression of molecular mobility. However, free nanoparticles (single particles or dry and dispersible agglomerates) can enter the gas phase during combustion processes, presenting a risk of inhalation. Extensive research programs launched for the development of new nanostructured flame retardants for polymeric materials have already shown some beneficial effects, such as a decrease in the rate of heat release, the limitation of dripping and the improvement of extinguishable properties. The use of free nanoparticles results in an unacceptable risk.
On the contrary, gradient systems and nanostructured micrometric materials represent a viable way.
Multifunctionality has the great potential to simplify the science and engineering of materials by having only one material that does the job of many. In the case of wood formulations, different requirements must be met, in addition to those relating to the impact on human health (previous paragraph). The identified nanostructured additives have allowed to increase flame resistance, scratch resistance and wear resistance. In addition, in the case of commercial products, it was necessary to consider the cost, density, color, recyclability, environmental impact and compatibility with polymeric matrices, oils and resins from renewable sources. With such a long list of requirements, it was not easy to find nanostructured materials that could meet all needs.