This project is regarding glue, finding the optimal temperature for glue to be applied for maximum adhesiveness, or its ability to stick to a surface and its strength. This is to help industries use glue more effectively.
First, what do we know about glue? We know first that while it is usually called glue, the proper term for it is an adhesive so that is what we will be using for this part of the paper.
The temperature of adhesive systems can alter some of the properties of monomer solutions, such as viscosity and degree of conversion, which are important bond effectiveness parameters. (1. Silikas N & Watts DC (1999) Rheology of urethane dimethacrylate and diluent formulations Dental Materials 15(4) 257-261. 2. Andrzejewska E (2001) Photopolymerization kinetics of multifunctional monomers Progress in Polymer Science 26(3) 605-665.)
We also know that there are two types of bonding that make glue possible, mechanical and chemical bonding. For mechanical bonding, the adhesive penetrates the holes, cracks and crevices of the material and solidifies (William D. Callister Jr., David G. Rethwish (2010). Materials Science and Engineering: an Introduction. (8th ed.) John Wiley & Sons, Inc.). This results in the glue being markedly more difficult to pull out of these holes, somewhat akin to trying to pull your hands out of handcuffs.
Chemical bonding, on the other hand, uses forces known as cohesive adhesive forces to adhere themselves together as well as to the materials you are trying to stick together (Petrucci, et al. General Chemistry: Principles & Modern Applications: AIE (Hardcover). Upper Saddle River: Pearson/Prentice Hall, 2007).Our independent variables in this case would be the temperature of the adhesive upon application. Dependent variables are the amount of mass the adhesive allows the joint to withstand before it sags to touch the ground. Controlled variables are the type of adhesive used (UHU glue), the time provided for the adhesive to dry (5 minutes), length of the boards and the position of the supports relative to the boards.
1.1 Research Questions
What is the optimal temperature to apply glue in?
What causes some glue applied to be of limited adhesiveness?
As glue is supposed to have decreased stability at high temperatures (Kinloch, p. 2.), we hypothesise that as the temperature of glue increases, its adhesive strength decreases and conversely when its temperature decreases, its adhesive strength increases.