Standard Glycol Adipate Polyols
Tri-iso distributes a wide range of standard glycol adipate polyols that allow formulators to produce high quality polyurethane adhesives. Polyols contain reactive hydroxyl (OH) groups which react with isocyanate (NCO) groups on isocyanates to form polyurethane adhesives.
Standard glycol adipate -based polyurethane adhesives enhanced UV resistance, excellent resistance to oils and fuels, and better abrasion resistance and tensile and tear strength compared to polyether-based polyurethane adhesives. However, polyester-based polyurethane adhesives are more susceptible to hydrolysis and provide poor resistance to weak acids and bases compared to polyether-based polyurethane adhesives.
Standard glycol adipate polyols are formed by the condensation reaction of a glycol with a dicarboxylic acid. The nature of this reaction results in a relatively high polydispersity (broad molecular weight distribution).
There are several key characteristics which define what performance properties a given glycol adipate polyol will impart in a given polyurethane adhesive. These characteristics include: the hydroxyl number or hydroxyl value (OH value), OH equivalent weight, molecular weight, and the functionality of the glycol adipate polyol.
Hydroxyl number (OH ) is the measure of the hydroxyl group content of gram of polyol. Hydroxyl value is measured by titrating a known mass of glycol adipate polyol against potassium hydroxide (KOH), and is expressed as mg KOH/g. Lower hydroxyl values indicate lower hydroxyl content and a higher molecular weight for the overall glycol adipate polyol.
OH equivalent weight is the number of grams of a given product that contains one equivalent of hydroxyl groups (NCO). Equivalent weight = 56100/OH
Molecular Weight is determined by multiplying the equivalent weight by the glycol adipate polyol functionality
Polyol functionality refers to the number of OH groups per molecule. Increasing the number of OH groups results in greater crosslinking. Greater crosslinking yields stiffer, harder products with enhanced chemical and thermal resistance. Polyols that contain 2 hydroxyl groups are called diols, polyols with 3 functional groups are called triols, polyol groups with 4 hydroxyl groups are called tetrols.
Your Tri-iso Technical Sales Representative is available to assist you in the selection of the appropriate standard glycol adipate polyol that will provide the specific properties you are trying to obtain. Click here to request a quote.