Provided is a novel fiberglass binder comprising a polycarboxy polymer and a polyol. The amount of polycarboxy polymer and polyol contained in the binder is such that the ratio of equivalents of hydroxyl groups to carboxy groups is preferably in the range from about 0.6/1 to 0.8/1. It is further preferred that the molecular weight of the polycarboxy polymer is less than 10,000, and more preferably less than 5000.