EFFECTS OF CHEMICAL MODIFICATION OF LIGNIN IN THE PREPARATION OF LIGNIN-UVCURABLE RESINS

摘要

The effect of chemical modification of lignin with glycidyl methacrylate (GMA) in preparation of lignin-UV curable systems was studied. The lignin was treated by GMA with different ratio of GMA: Lignin (1:1, 2:1 and 3:1). The treated lignin was then incorporated into aliphatic urethane acrylate with the presence of photoinitiator and surfactant. The mixture was cured by 1ST Strahlentechnik UV machine with a UV radiation range of 180-450 nm. Various testing on the film were conducted such as gel content, pendulum hardness, cross hatch adhesion, abrasion resistance and Fourier transform infrared spectroscopy (FTIR). From the results of weight percentage gain (WPG) and iodine number, more unsaturation sites were found in lignin after it was treated with GMA. FTIR studies showed the unsaturated group of the treated lignin was consumed after it was exposed to UV radiation. The incorporation of GMA treated lignin as a filler in UV curable resin had enhanced the strength of the coating film (5% loading oftreated lignin). However, further increment of the amount of GMA treated lignin has decreased the strength of the film. This was due to the plasticization effect of GMA treated lignin. In addition, the abrasion resistance of the film was also enhanced with the presence of lignin.