Reactive latex blends for the woodworking industry

20. July 2021

A new IHD research project jointly pursued with the Fraunhofer Institute for Applied Polymer Research (IAP) is aimed at developing a reactive latex blend and test its usability for practical application.

The research idea behind it is to apply a novel crosslinking concept on the basis of a reactive latex blend for water-resistant 1K-PVAc dispersion adhesives. In contrast to commercial systems, this concept is based on a PVAc adhesive formulation consisting of two complementary functionalised PVAc latex dispersions, the so-called “two-component adhesive in a single pot”.

The functional groups are selected in the project in such a way that they react with each other only at increased temperatures, thus crosslinking the adhesive film and achieving adhesive joints of high water resistance. This reactive latex mixture can avoid undesirable discoloration of wood, e.g., caused by tannic acid reactions.

Reluctance of the functional groups to react at room temperature allows their storage as a one-component system. The concept is based on the idea that the reactive groups in the dispersion are limited to individual latex particles and are, therefore, unable to react with each other. This ensures the required storage stability over a longer period of time. However, after application of the system, polymer diffusion across interparticle boundaries should bring the reactive groups into contact and cause them to react, this process taking place during hot pressing in the press.

The principal feasibility of the new crosslinking concept could be demonstrated in a previous IGF project, but the results achieved revealed some remaining challenges. Further need for research mainly consists in the scalability on order to obtain a ready-to-use solution.

Contact at the IHD:
Christoph Scheffel
christoph.scheffel@ihd-dresden.de

Contact at the IAP:
Dr. Daniel Zehm
daniel.zehm@iap.fraunhofer.de