SRAY-APPLIED POLYURETHANE foam is a unique roofing material. It is sprayed as a liquid directly onto the roofing substrate; within seconds it foams, expanding 20 to 30 times its original volume.
Their properties are categorized based on the foam structure. The foam has two types of structure:(1) Open-cell structure (2) Closed-cell structure.
The basic chemistry of flexible polyurethane foams is not difficult to grasp. It is the reaction of an alcohol or OH group with an isocyanate or NCO group.
On Oct 18, MEE announced that use of HCFC-141b, a.k.a. Dichlorofluoroethane, will be prohibited in three industries, namely refrigerator & freezer ,...