Preparation and Characterization of Flame Retardant Polyurethane Acrylate UV Curing Adhesive

Abstract

P and N flame retardant elements were introduced into the molecular structure of prepolymer PUA by grafting and copolymerizing with discussing the factors of synthetizing phosphorus-containing and phosphorus-containing urethane acrylates. Besides, the mechanical properties, flame retardancy and thermal stability of the UV-curable adhesive prepared were investigate. The results show that when n(HMDI): n(PDEGA3000): n(FRC-2): n(HEA)=2.3: 1: 1: 1, w(DBTDL)=0.3%, w(MEHQ)=0.3%, w(HDDA)=20%, a prepolymer P-PUA1 with of Mn 7200 and PDI of 1.53 was synthesized; when n(HMDI): n(FRC-6): n(HEA)=2.05: 1: 2, w(DBTDL)=0.45%, w(MEHQ)=0.3%, w(HDDA)=20%, a prepolymer P-PUA2 with of Mn 1800 and PDI of 1.02 was synthesized; when m(PUA): m(P-PUA1): m(P-PUA2)=1: 1: 1, w(Irgacure1173)=3%, w(dimethylaniline)=2%, w(HDDA)=25%, a UV-curable adhesive with the viscosity of 6900 mPa•s, shear strength of 8.19 MPa, hardness of 57 HD, LOI of 25%, flame retardant grade of UL94V-2, and excellent thermal stability can be obtained.