Due to the increasing interest in applying a wider range of wood species for structural purposes, nine European softwood and hardwood species (ash, beech, birch, hornbeam, larch, oak, poplar, black locust and spruce) were assessed for their ability to be bonded with three different commercial adhesive systems (melamineurea-formaldehyde, one-component polyurethane and phenol-resorcinol-formaldehyde). Tensile shear strength and delamination tests were conducted according to European standards, for all tests including the corresponding wood species as adhesive joints and as a solid wood reference. When tested in dry condition, the threshold of solid wood tensile shear strength was reached by all species-adhesive combinations. By contrast, testing in wet condition revealed distinct performance reductions for certain combinations. This trend was confirmed by delamination testing. Overall, the results indicate that extrapolation of test results achieved with a specific wood species (as recommended in the current standard for lapjoint tests) towards other species is highly problematic and has to be done with caution.

Coatings fulfill an important function in providing functionality and service life to wood surfaces. In the present study, the potential of nanocellulosic fillers toward improving waterborne wood coating mechanics is evaluated using free-standing coating films. At 2% filler content, significant improvements in static and dynamic mechanical properties were observed. The extent of these improvements was different depending on whether high-aspect-ratio cellulose nanofibrils of short cellulose nanocrystals were used. Chemical surface modification of cellulose nanofibrils did not provide further improvement. The water-vapor sorption properties of the coating films, which were also evaluated, did not show significant effects due to addition of nanocellulose, while optical transparency slightly decreased.

The synthesis of polyamides and poly­(ester amide)­s derived from 2,5-furandicarboxylic acid frequently leads to amorphous polymeric materials. Formation of intramolecular hydrogen bonds between the oxygen heteroatom in the furan ring and hydrogens of the amide bonds reduces the intermolecular hydrogen bonds that are usually responsible for the high thermal and mechanical performance of these materials. To circumvent this problem, aliphatic–aromatic poly­(ester amide)­s were synthesized in this study from dimethyl 2,5-furandicarboxylate, 1,10-decanediol, and a preformed aliphatic diol containing two internal amide bonds (amido diol). Wide-angle X-ray diffraction and differential scanning calorimetry experiments revealed that polymers obtained were semicrystalline over the whole composition range and crystallized rapidly from the molten state, indicating that intramolecular H-bonding is effectively suppressed. Depending on the ratio of 1,10-decanediol and amido diol, the thermal properties could be adjusted over a wide temperature range. The polymers exhibit T g and T m in a range of −4 to 27 °C and 102 to 175 °C, respectively. Elastic modulus and hardness increased almost linearly with the amount of ester–amide moieties. The method presented herein allows for the successful synthesis of semicrystalline poly­(ester amide)­s from 2,5-furandicarboxylic acid without undesired intramolecular hydrogen bonds. This finding could set the stage for further bio-based poly­(ester amide)­s from 2,5-furandicarboxylic acid suitable for high-performance applications.