Executive Summary : | Polymeric methylene diphenyl diisocyanate (pMDI) is one of the commonly used adhesive for bonding wood materials. The faster reactivity of isocyanates with wood material makes them best suitable for using them in wood bonding applications. However, achieving a uniform bondline thickness with these adhesives is a major problem. This is due to excess permeation of isocyanates into the pores of wood material. Non-uniform bondline thickness problem can be minimized by adding the compatible fillers in pMDI. In this present work, it is proposed to utilize the green fillers compatible with wood and pMDI i.e. cellulosic fillers. Cellulosic fillers are compatible with wood; they are rich in hydroxyl groups which can readily react with pMDI. Cellulosic fillers like microcrystalline cellulose, lignin, and lignocellulosic fillers are proposed to use in this work. Lignin and lignocellulose will be extracted from Tamarindus indica bark which has rich in lignin content. The results will be compared with microcrystalline cellulose reinforced samples. With increasing industrial demand for wood based products, the effect of functional green fillers on the bondline thickness need to be estimated. The reaction rate of fillers with wood and pMDI will be studied using Fourier transform infrared spectroscopy. The effect of fillers addition on lap-shear strength of bonded joints and their thermal stability will be studied in detail at different weight fractions of fillers. Finally, long-term durability of all the joints will be studied. |