Microwave Produced Tannin-furanic Foams

A new method to produce formaldehyde-free tannin-based furanic foams has been developed. The use of microwaves as energy source allows homogeneous tannin foams to be produced in a very short time. In this paper the main characteristics of these foams are investigated and compared to the state of the art. It has been seen that the microwave production allows a high degree of repeatability in terms of bulk density. The microwave-produced foams have shown similar features to the previous tannin-furanic foams produced in the hot-press or in the oven. The high water affinity of these materials has allowed the study of partial recovering of the catalystwhile the increased fire resistance of the tannin-furanic foams leads to the assumption that there is an important effect onthe degree of polymerization in the fire resistance of these innovative, natural materials.