Tri-iso distributes a wide range of polycarbonate polyols that allow formulators to produce high quality polyurethane sealants. Polyols contain reactive hydroxyl (OH) groups which react with isocyanate (NCO) groups on isocyanates to form polyurethane sealants.
Polycarbonate diols are premium polyester polyols. Compared to standard polyester polyols, polycarbonate diols provide significantly enhanced hydrolytic stability, impact resistance, hardness, and chemical resistance. Polycarbonate-polyurethane sealants enhanced UV resistance, excellent resistance to oils and fuels, and better abrasion resistance and tensile and tear strength compared to polyether-based polyurethane sealants.
There are several key characteristics which define what performance properties a given polycarbonate diol will impart in a given polyurethane sealant. These characteristics include: the hydroxyl number or hydroxyl value (OH value), OH equivalent weight, and the molecular weight
Hydroxyl number (OH ) is the measure of the hydroxyl group content of gram of polycarbonate diol. Hydroxyl value is measured by titrating a known mass of polyol against potassium hydroxide (KOH), and is expressed as mg KOH/g. Lower hydroxyl values indicates lower hydroxyl content and a higher molecular weight for the overall polycarbonate diol..
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 polyol functionality (2).
Your Tri-iso Technical Sales Representative is available to assist you in the selection of the appropriate polycarbonate diol that will provide the specific properties you are trying to obtain. Click here to request a quote.