• Nowadays adhesive structural bonding has become a bigger alternative to welding and brazing in industries.
• The adhesive should wet the adherents surface before it cures to achieve good adhesion, making accelerated curing with properties necessary to get the desired properties.
• The one component moisture curable adhesives take more time to achieve handling strength due to which longer fixation times are required after the installation for the joints to develop handling strength without slipping.
• By the artificial addition of moisture/hydroxyl groups (or both), the low curing rate is reduced by accelerated curing rate and reduced fixation time significantly.
• Therefore, there is a need for improved cellulosic particle-based one-component polyurethane adhesive wherein the cellulosic particles act as relative fillers and moisture reservoirs for enhancing the curing rate and addressing the mentioned issues.

Present Patent literature discloses a method for preparing cellulosic particle-based one-component polyurethane adhesive material. The method comprises the steps of:

• Pre-heating one-component polyurethane adhesive (PU) at 80 degree C for 2 to 3 hours.
• Pre-heating the filter material (either Microcrystalline Cellulose (MCC) or Saw Dust (SD)) that acts as a reactive filter and moisture reservoir.
• The filter material is well dispersed in the PU adhesive results in quick consumption of isocyanates, thereby reinforced polyurethane bonded joints showed improved lap-shear strength with little strain reduction.

A graphical representation of the lap shear configuration of the cellulosic particle based one-component polyurethane adhesive is shown in FIG 1, and shapes of microcrystalline cellulose & sawdust powder particles with insets are shown the particle size distribution respectively is shown in FIG 2.

The method for preparing the Cellulosic Particles Based One-component Polyurethane Adhesive PU adhesive is given in the following steps:

• Pre-heating one-component polyurethane adhesive (PU) at 80 degree C for 2-3 hours to facilitate thorough mixing of at least one filler material (MCC and SD).
• Pre-heating the filler material at 80 degree C for 3 hours.
• The one-component polyurethane adhesive (PU) is manually mixed with the filler material (Microcrystalline Cellulose (MCC) and Saw Dust (SD)) for 2 minutes in order obtain enhanced curing rate of moisture curable one-component polyurethane adhesive.