Bio-based aerospace composites

Important results from the project

Bio-based materials which technically and performance-wise surpasses today´s fossil-based materials in advanced applications and which solves concrete technical problems in a unique way, can pave the way for a broader industrial implementation of bio-based materials. Bio-based benzoxazines have the potential for lower dielectric loss factor and lower water uptake than today´s fossil -based materials. Laser carbonization with the aim to create structures preventing static electricity has been demonstrated. High temperature resistance is also a desirable property.

Expected long term effects

New variants of bio-based benzoxazines were developed for lower melting points and to enable filling of fabrics and molds in composite production. A unimolecular resin based on naringenine benzoxazine (NarBz) has been prepared. The availability of a unimolecular resin system is expected to have the effect of making it easier to correlate molecular structure with properties which can facilitate material development. Achieved results show that bio-based benzoxaziner are promising as future aerospace composites.

Approach and implementation

The initial syntheses gave monomers with too high a melting point preventing composite casting, and new monomers were developed. The method of processing cast benzoxazine specimens to exact dimension did not work as planned. The existing method of laminating benzoxazines between sheets of foam plastic led to the migration of monomers into the foam plastic and to uncertainties in dielectric measurements. These problems led to the failure to obtain reliable measurements of dielectric losses. In the future, methods to casting sample into exact dimensions are planned.