The Study Of Reinforcement And Flame Retardation Of Phenolic Foam

The synthesis process of fire retardant thermal insulation phenolic resin foam was fully studied and improved in this work. More specifically, synthetic conditions of foamable phenolic resin, the foaming process, factors effecting on reinformance and flame retardation properties of the as-prepared phenolic foam, cost accounting for the whole industrial production process were studied in this work.Firstly, in the foamable phenolic resin synthetic process, formaldehyde solution was replaced by paraformaldehyde partly. Therefore, there is no industrial effluents containing phenol and methanal during this process, since it is no need to distill the water from the foamable resin. Sodium hydroxide, barium hydroxide and N,N-Dimethylethanolamine were taken together as catalyst to synthesise the foamable resin, which present high solid content,short gel time and modest viscosity. Also, the viscosity was monitoring timely by testing its refractive index in the synthetic process, which made the test of resin’s viscosity more easier than the traditional ways.Secondly, the resin’s viscosity, the amount of foam stabilizer, the selection of different foaming agent and different kinds of curing agent were studied in the process of producing phenolic foam. The formed foam was characterized using SEM to have smaller cells with a diameter of 50-60 μm and a hexagon shape. The optimal parameters for the synthesis process was also obtained. The resin’s viscosity was better in the range of 3000 ± 500 MPa·s, while polydimethylsiloxane and tween-80 taken as foam stabilizer was better with the same quality.Petroleum ether with the boiling point of(30-60 ℃) was taken as foaming agent and the curing agent was phenolsulphonic acids which had good intermiscibility with resin. Moreover,the foaming process was better performed in the temperature of 80 ± 5 ℃.Thirdly, it was found that flexibilizer-1 and flexibilizer-2 were added into the resin to enhance the tensile strength of phenolic foam. As a cross-linking agent, glycerinum can increase the crosslinking density of the resin. The adding of flexibilizer-1 and flexibilizer-2can improve the oxygen index, enhance the tensile strength and reduce the decreasing of thermostability of phenolic foam.Fourthly, the fire resistance of phenolic foam was investigated by adding different kinds of flame retardants. The binary and ternary mixture of flame retadants showed a better fire resistantce performance than using the unitary flame retardant solely. The sample containing ternary flame retardants is 100 ℃ higher than the sample without any flame retardants inTPO process when the weight loss is 50%. The expandable graphite was empolied to reduce the heat conductivity coefficient, which will increase by the adding of flame retardants.Finally, pilot scale experiments were performed based on our bench scale results to optimize the technological parameters in the industrial production. Cost accounting was calculated based on the production of 100 m3 of phenolic foam in the factory. The results showed that certain economic benefits will be created by employing our new technologies.