Two of those beams were laminated using phenol-resorcinol-formaldehyde (PRF) resin (5210J resin with 6310L hardener produced by Momentive Glue Company), while an additional two beams were laminated using a formaldehyde-free isocyanate resin (GT20 with a GT205 hardener produced by Purbond).
The constitutive behavior depicted in Figure 1 reinforces the fact the both types of beams had similar MOE, while the MOR for isocyanate resin was higher.
Polyurethane 2-pack paints, when mixed, cure by the reaction of a polyalcohol in Part A with an isocyanate resin
to form a urethane polymer (equation 1):
Effect of polyol on thermo-oxidative degradation of isocyanate resin
for wood adhesives.
For all cases, the amount of catalyst and polyol added was based on the volume of isocyanate resin
patent for the process technology of making a straw-based engineered board with isocyanate resin
According to a report prepared by CARB, urea formaldehyde resins cost about half as much as phenol formaldehyde resins and about one-fourth the cost of isocyanate resins
By definition, the isocyanate resins
contain nitrogen, and functionality is to some extent a measure of the isocyanate content.
However, he said some of the challenges these manufacturers must overcome include ironing out manufacturing bugs and costs associated with raw material procurement and the use of more expensive isocyanate resins
Both P-F resins and isocyanate resins
would add substantially to the cost of the product.