Preparation And Cure Kinetics Of Non-isocyanate Polyurethane

Traditional polyurethane has been widely applied because of its excellentperformance, but one of raw materials prepared PU is isocyanate. And there are manyproblems in the process of preparation and application. In this paper, different types ofcyclic carbonate were synthesized by different types of epoxy resin reacted with CO2.Then non-isocyanates were synthesized by cyclic carbonate reacted with polyamines.The relationship between structure and properties of NIPU has been also studied. Andthe material with excellent mechanical and thermal properties was prepared bychanging the ratio of raw materials.The main contents and conclusions of this paper were listed as follows:1) Poly-cyclic carbonates which have five-membered cyclic carbonate in theend of the molecular chain were prepared by poly-epoxy resin and non-toxic andresources-rich CO2. And NIPU was synthesized based on cyclic carbonate andpoly-amine. At the same time, the chemical structure of synthetic products wascharacterized by infrared spectrum (FI-IR) and nuclear magnetic resonance hydrogenspectrum (1H-NMR).2) Hybrid cyclic carbonate was prepared by using different mass ratio ofPEG400DGE and bis-phenol F epoxy resin NPEF-170. This paper also investigatedthe effect of type and the dosage of catalyst, reaction temperature, carbon dioxidepressure, reaction time on the reaction. The result showed that mixture epoxy resincould achieve better conversion rates when the catalyst was TBAB, the catalystconcentration was0.5%, reaction temperature was120℃, CO2pressure was1.8MPa,and reaction time was7h.3) The paper researched the curing kinetics of cyclic carbonate at different heating rates by non-isothermal DSC and optimized the curing process. The researchindicted that the initial temperature Ti, peak temperature Tpfinishing temperature Tfand reaction time were373.25K,448.70K,506.80K, and17min, respectively.4) Under the same conditions, this paper also studied the effect of differentproportions of cyclic carbonate on the mechanical properties and thermodynamicperformance of NIPU. The study showed that NIPU could achieve superior mechanicaland thermodynamic performance when the mass ratio of PEG-CC and NPEF-CC was7:3. The maximum tensile strength could reach7.58MPa, the elongation at failure was347%, and the glass transition temperature (Tg）could reach11.16℃.