Synthesis and properties of reactive polyurethane hot melt adhesive based on a novel phosphorus-nitrogen-containing polyol
Zhaoyong Lu, Weilan Xue, Zuoxiang Zeng, Zhiyuan Zhou
Abstract
A novel phosphorus-nitrogen-contaning polyol (BHAPE) was synthesized from formaldehyde solution, 2, 2'-iminodiethanol and diethly phosphite by typical Kabachnik-Fields reaction. Reactive polyurethane hot melt adhesives with hydrolysis resistance and enhanced flame retardant properties (HMPURs) were prepared from poly (1, 4-butylene adipate), poly (carbonate diol), poly (tetramethylene ether glycol) and BHAPE. The bonding strength, thermal stability, flame retardant performance, mechanical properties and hydrolytic resistance of the HMPURs were studied. The results illustrate that the incorporation of BHAPE for HMPURs could cause a higher thermal stability and more char yield. The melt viscosity, Young's modulus, tensile strength and elongation at break of HMPURs increase with the increase of BHAPE content, and then decrease when the BHAPE content reaches 4 wt%.The optimal content of BHAPE is 4–6wt% and the obtained HMPURs have the limit oxygen index (LOI) of 27.1–31.7% and the higher green strength. Meanwhile, introducing polycarbonate diol to HMPUR can effectively improve its hydrolysis resistance.