Kinetics Investigation of UV Curing of Tri (2, 3-epoxypropyl) Phosphate

Shiliang Fan1,3, Vanda Yu. Voytekunas1, Liliya Amirova2, Rustem Amirov2, Freddy Y.C. Boey3 and Marc J.M. Abadie1,3

1Polytech’Montpellier, Laboratory of Polymer Science & Advanced Organic Materials - LEMP/MAO, Université Montpellier 2, S.T.L., Place Bataillon, 34095 Montpellier Cedex 05, France

2Kazan State University, 18 Kremlyvoskaya st., Kazan. 420008, Republic of Tatarstan, Russian Federation
3Advanced Materials Research Centre, School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore

Abstract

Phosphorus function group has a kind of property to act as flame retardant. Materials incorporating such groups show higher performance in high temperature environment. A radiation curable phosphorus-containing epoxy resin, Tri (2, 3-epoxypropyl) Phosphate, possessing high performance of thermal stability, was synthesized with high yield and investigated by using the differential photo calorimetry (DPC), FTIR and TGA. The photo curing process and kinetics (enthalpy, induction time, time to reach the peak maximum, degree of conversion, rate coefficient) were conducted by using DPC. The reaction conditions, such as temperature, concentration of photoinitiator (Cyracure@ UVI-6974, purchased from Dow Chemical), the intensity of the UV lamp used, were optimized systematically. The curing behavior was analyzed by using an autocatalytic model. The activation energy, conversion and reaction rate were calculated. The results indicate that the UV curing reaction is fast with high conversion ratio, but it is also controlled strictly by temperature and was affected strongly by the viscosity of the multi-functionalized resins. The thermal resistance properties were studied. Thermal degradation behavior was also investigated by using TGA. The temperature at 5% weight loss Td is around 180°C. Comparing with the normal epoxy products, the result shows that the thermal resistance of such epoxy coating film was improved relatively due to the existing phosphorus group.