Preparation, characterization, and performance of cross-linkable maltodextrin-based lignocellulosic adhesives

A rapid-setting, starch-based lignocellulosic adhesive is described which could be cured at ambient temperature to form a film having a clear appearance and significant moisture resistance when tested under ambient conditions. Maltodextrins with a dextrose equivalent (DE) range of 5-25 were reacted as an intimate mixture in the dry state with N-methylolacrylamide (N-MAM) to give products containing the corresponding carbohydrate methyleneacrylamido ethers, which were characterized by NMR spectroscopy and electrospray mass spectrometry. The reaction products, comprising mixtures of maltodextrins and methyleneacrylamido ethers, were formulated in water for paper adhesive use and tested for performance, Paper strip peel tests showed a time to fibre tear of 2 min, an initial time to paper tear of 5 min, and 10 min to full paper adhesion. The failure load was 2.4 kN, diminishing to I kN after a 24 h cold water soak.